<!--
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# DSL: Ash.Resource.Dsl
## attributes
A section for declaring attributes on the resource.
### Nested DSLs
* [attribute](#attributes-attribute)
* [create_timestamp](#attributes-create_timestamp)
* [update_timestamp](#attributes-update_timestamp)
* [integer_primary_key](#attributes-integer_primary_key)
* [uuid_primary_key](#attributes-uuid_primary_key)
### Examples
```
attributes do
uuid_primary_key :id
attribute :first_name, :string do
allow_nil? false
end
attribute :last_name, :string do
allow_nil? false
end
attribute :email, :string do
allow_nil? false
constraints [
match: ~r/^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+.[a-zA-Z0-9-.]+$/
]
end
attribute :type, :atom do
constraints [
one_of: [:admin, :teacher, :student]
]
end
create_timestamp :inserted_at
update_timestamp :updated_at
end
```
## attributes.attribute
```elixir
attribute name, type
```
Declares an attribute on the resource.
### Examples
```
attribute :name, :string do
allow_nil? false
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-name" href="#attributes-attribute-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the attribute.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-type" href="#attributes-attribute-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the attribute. See `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-constraints" href="#attributes-attribute-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Constraints to provide to the type when casting the value. For more, see the [constraints topic](/documentation/topics/constraints.md).
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-description" href="#attributes-attribute-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the attribute.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-sensitive?" href="#attributes-attribute-sensitive?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sensitive?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute value contains sensitive information, like PII. See the [Security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-source" href="#attributes-attribute-source">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
source
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
If the field should be mapped to a different name in the data layer. Support varies by data layer.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-always_select?" href="#attributes-attribute-always_select?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
always_select?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not to ensure this attribute is always selected when reading from the database, regardless of applied select statements.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-primary_key?" href="#attributes-attribute-primary_key?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
primary_key?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether the attribute is the primary key. Composite primary key is also possible by using `primary_key? true` in more than one attribute. If primary_key? is true, allow_nil? must be false.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-allow_nil?" href="#attributes-attribute-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute can be set to nil. If nil value is given error is raised.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-generated?" href="#attributes-attribute-generated?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
generated?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the value may be generated by the data layer.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-writable?" href="#attributes-attribute-writable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
writable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the value can be written to. Non-writable attributes can still be written with `Ash.Changeset.force_change_attribute/3`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-private?" href="#attributes-attribute-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
The attribute is not publically writable, and should not be exposed over any public interfaces. See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-default" href="#attributes-attribute-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(-> any) | mfa | any()</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A value to be set on all creates, unless a value is being provided already.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-update_default" href="#attributes-attribute-update_default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
update_default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(-> any) | mfa | any()</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A value to be set on all updates, unless a value is being provided already.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-filterable?" href="#attributes-attribute-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute can be referenced in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-attribute-match_other_defaults?" href="#attributes-attribute-match_other_defaults?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
match_other_defaults?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Ensures that other attributes that use the same "lazy" default (a function or an mfa), use the same default value. Has no effect unless `default` is a zero argument function.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Attribute`
## attributes.create_timestamp
```elixir
create_timestamp name
```
Declares a non-writable attribute with a create default of `&DateTime.utc_now/0`
Accepts all the same options as `d:Ash.Resource.Dsl.attributes.attribute`, except it sets
the following different defaults:
writable? false
private? true
default &DateTime.utc_now/0
match_other_defaults? true
type Ash.Type.UTCDatetimeUsec
allow_nil? false
### Examples
```
create_timestamp :inserted_at
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-name" href="#attributes-create_timestamp-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the attribute.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-type" href="#attributes-create_timestamp-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
<code class="inline">Ash.Type.UtcDatetimeUsec</code>
</td>
<td style="text-align: left" colspan=2>
The type of the attribute. See `Ash.Type` for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-constraints" href="#attributes-create_timestamp-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Constraints to provide to the type when casting the value. For more, see the [constraints topic](/documentation/topics/constraints.md).
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-description" href="#attributes-create_timestamp-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the attribute.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-sensitive?" href="#attributes-create_timestamp-sensitive?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sensitive?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute value contains sensitive information, like PII. See the [Security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-source" href="#attributes-create_timestamp-source">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
source
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
If the field should be mapped to a different name in the data layer. Support varies by data layer.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-always_select?" href="#attributes-create_timestamp-always_select?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
always_select?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not to ensure this attribute is always selected when reading from the database, regardless of applied select statements.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-primary_key?" href="#attributes-create_timestamp-primary_key?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
primary_key?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether the attribute is the primary key. Composite primary key is also possible by using `primary_key? true` in more than one attribute. If primary_key? is true, allow_nil? must be false.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-allow_nil?" href="#attributes-create_timestamp-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute can be set to nil. If nil value is given error is raised.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-generated?" href="#attributes-create_timestamp-generated?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
generated?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the value may be generated by the data layer.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-writable?" href="#attributes-create_timestamp-writable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
writable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the value can be written to. Non-writable attributes can still be written with `Ash.Changeset.force_change_attribute/3`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-private?" href="#attributes-create_timestamp-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
The attribute is not publically writable, and should not be exposed over any public interfaces. See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-default" href="#attributes-create_timestamp-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(-> any) | mfa | any()</code>
</td>
<td style="text-align: left">
<code class="inline">&DateTime.utc_now/0</code>
</td>
<td style="text-align: left" colspan=2>
A value to be set on all creates, unless a value is being provided already.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-update_default" href="#attributes-create_timestamp-update_default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
update_default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(-> any) | mfa | any()</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A value to be set on all updates, unless a value is being provided already.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-filterable?" href="#attributes-create_timestamp-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute can be referenced in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-create_timestamp-match_other_defaults?" href="#attributes-create_timestamp-match_other_defaults?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
match_other_defaults?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Ensures that other attributes that use the same "lazy" default (a function or an mfa), use the same default value. Has no effect unless `default` is a zero argument function.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Attribute`
## attributes.update_timestamp
```elixir
update_timestamp name
```
Declares a non-writable attribute with a create and update default of `&DateTime.utc_now/0`
Accepts all the same options as `d:Ash.Resource.Dsl.attributes.attribute`, except it sets
the following different defaults:
writable? false
private? true
default &DateTime.utc_now/0
match_other_defaults? true
update_default &DateTime.utc_now/0
type Ash.Type.UTCDatetimeUsec
allow_nil? false
### Examples
```
update_timestamp :updated_at
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-name" href="#attributes-update_timestamp-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the attribute.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-type" href="#attributes-update_timestamp-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
<code class="inline">Ash.Type.UtcDatetimeUsec</code>
</td>
<td style="text-align: left" colspan=2>
The type of the attribute. See `Ash.Type` for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-constraints" href="#attributes-update_timestamp-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Constraints to provide to the type when casting the value. For more, see the [constraints topic](/documentation/topics/constraints.md).
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-description" href="#attributes-update_timestamp-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the attribute.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-sensitive?" href="#attributes-update_timestamp-sensitive?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sensitive?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute value contains sensitive information, like PII. See the [Security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-source" href="#attributes-update_timestamp-source">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
source
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
If the field should be mapped to a different name in the data layer. Support varies by data layer.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-always_select?" href="#attributes-update_timestamp-always_select?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
always_select?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not to ensure this attribute is always selected when reading from the database, regardless of applied select statements.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-primary_key?" href="#attributes-update_timestamp-primary_key?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
primary_key?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether the attribute is the primary key. Composite primary key is also possible by using `primary_key? true` in more than one attribute. If primary_key? is true, allow_nil? must be false.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-allow_nil?" href="#attributes-update_timestamp-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute can be set to nil. If nil value is given error is raised.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-generated?" href="#attributes-update_timestamp-generated?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
generated?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the value may be generated by the data layer.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-writable?" href="#attributes-update_timestamp-writable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
writable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the value can be written to. Non-writable attributes can still be written with `Ash.Changeset.force_change_attribute/3`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-private?" href="#attributes-update_timestamp-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
The attribute is not publically writable, and should not be exposed over any public interfaces. See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-default" href="#attributes-update_timestamp-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(-> any) | mfa | any()</code>
</td>
<td style="text-align: left">
<code class="inline">&DateTime.utc_now/0</code>
</td>
<td style="text-align: left" colspan=2>
A value to be set on all creates, unless a value is being provided already.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-update_default" href="#attributes-update_timestamp-update_default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
update_default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(-> any) | mfa | any()</code>
</td>
<td style="text-align: left">
<code class="inline">&DateTime.utc_now/0</code>
</td>
<td style="text-align: left" colspan=2>
A value to be set on all updates, unless a value is being provided already.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-filterable?" href="#attributes-update_timestamp-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute can be referenced in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-update_timestamp-match_other_defaults?" href="#attributes-update_timestamp-match_other_defaults?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
match_other_defaults?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Ensures that other attributes that use the same "lazy" default (a function or an mfa), use the same default value. Has no effect unless `default` is a zero argument function.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Attribute`
## attributes.integer_primary_key
```elixir
integer_primary_key name
```
Declares a generated, non writable, non-nil, primary key column of type integer.
Generated integer primary keys must be supported by the data layer.
Accepts all the same options as `d:Ash.Resource.Dsl.attributes.attribute`, except for `allow_nil?`, but it sets
the following different defaults:
writable? false
primary_key? true
generated? true
type :integer
### Examples
```
integer_primary_key :id
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-name" href="#attributes-integer_primary_key-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the attribute.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-type" href="#attributes-integer_primary_key-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
<code class="inline">:integer</code>
</td>
<td style="text-align: left" colspan=2>
The type of the attribute. See `Ash.Type` for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-constraints" href="#attributes-integer_primary_key-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Constraints to provide to the type when casting the value. For more, see the [constraints topic](/documentation/topics/constraints.md).
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-description" href="#attributes-integer_primary_key-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the attribute.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-sensitive?" href="#attributes-integer_primary_key-sensitive?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sensitive?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute value contains sensitive information, like PII. See the [Security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-source" href="#attributes-integer_primary_key-source">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
source
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
If the field should be mapped to a different name in the data layer. Support varies by data layer.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-always_select?" href="#attributes-integer_primary_key-always_select?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
always_select?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not to ensure this attribute is always selected when reading from the database, regardless of applied select statements.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-primary_key?" href="#attributes-integer_primary_key-primary_key?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
primary_key?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether the attribute is the primary key. Composite primary key is also possible by using `primary_key? true` in more than one attribute. If primary_key? is true, allow_nil? must be false.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-generated?" href="#attributes-integer_primary_key-generated?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
generated?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the value may be generated by the data layer.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-writable?" href="#attributes-integer_primary_key-writable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
writable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the value can be written to. Non-writable attributes can still be written with `Ash.Changeset.force_change_attribute/3`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-private?" href="#attributes-integer_primary_key-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
The attribute is not publically writable, and should not be exposed over any public interfaces. See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-default" href="#attributes-integer_primary_key-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(-> any) | mfa | any()</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A value to be set on all creates, unless a value is being provided already.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-update_default" href="#attributes-integer_primary_key-update_default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
update_default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(-> any) | mfa | any()</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A value to be set on all updates, unless a value is being provided already.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-filterable?" href="#attributes-integer_primary_key-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute can be referenced in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-integer_primary_key-match_other_defaults?" href="#attributes-integer_primary_key-match_other_defaults?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
match_other_defaults?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Ensures that other attributes that use the same "lazy" default (a function or an mfa), use the same default value. Has no effect unless `default` is a zero argument function.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Attribute`
## attributes.uuid_primary_key
```elixir
uuid_primary_key name
```
Declares a non writable, non-nil, primary key column of type `uuid`, which defaults to `Ash.UUID.generate/0`.
Accepts all the same options as `d:Ash.Resource.Dsl.attributes.attribute`, except for `allow_nil?`, but it sets
the following different defaults:
writable? false
default &Ash.UUID.generate/0
primary_key? true
generated? true
type :uuid
### Examples
```
uuid_primary_key :id
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-name" href="#attributes-uuid_primary_key-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the attribute.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-type" href="#attributes-uuid_primary_key-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
<code class="inline">:uuid</code>
</td>
<td style="text-align: left" colspan=2>
The type of the attribute. See `Ash.Type` for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-constraints" href="#attributes-uuid_primary_key-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Constraints to provide to the type when casting the value. For more, see the [constraints topic](/documentation/topics/constraints.md).
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-description" href="#attributes-uuid_primary_key-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the attribute.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-sensitive?" href="#attributes-uuid_primary_key-sensitive?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sensitive?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute value contains sensitive information, like PII. See the [Security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-source" href="#attributes-uuid_primary_key-source">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
source
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
If the field should be mapped to a different name in the data layer. Support varies by data layer.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-always_select?" href="#attributes-uuid_primary_key-always_select?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
always_select?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not to ensure this attribute is always selected when reading from the database, regardless of applied select statements.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-primary_key?" href="#attributes-uuid_primary_key-primary_key?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
primary_key?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether the attribute is the primary key. Composite primary key is also possible by using `primary_key? true` in more than one attribute. If primary_key? is true, allow_nil? must be false.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-generated?" href="#attributes-uuid_primary_key-generated?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
generated?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the value may be generated by the data layer.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-writable?" href="#attributes-uuid_primary_key-writable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
writable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the value can be written to. Non-writable attributes can still be written with `Ash.Changeset.force_change_attribute/3`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-private?" href="#attributes-uuid_primary_key-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
The attribute is not publically writable, and should not be exposed over any public interfaces. See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-default" href="#attributes-uuid_primary_key-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(-> any) | mfa | any()</code>
</td>
<td style="text-align: left">
<code class="inline">&Ash.UUID.generate/0</code>
</td>
<td style="text-align: left" colspan=2>
A value to be set on all creates, unless a value is being provided already.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-update_default" href="#attributes-uuid_primary_key-update_default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
update_default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(-> any) | mfa | any()</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A value to be set on all updates, unless a value is being provided already.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-filterable?" href="#attributes-uuid_primary_key-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the attribute can be referenced in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="attributes-uuid_primary_key-match_other_defaults?" href="#attributes-uuid_primary_key-match_other_defaults?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
match_other_defaults?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Ensures that other attributes that use the same "lazy" default (a function or an mfa), use the same default value. Has no effect unless `default` is a zero argument function.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Attribute`
## relationships
A section for declaring relationships on the resource.
Relationships are a core component of resource oriented design. Many components of Ash
will use these relationships. A simple use case is loading relationships (done via the `Ash.Query.load/2`).
See the [relationships guide](/documentation/topics/relationships.md) for more.
### Nested DSLs
* [has_one](#relationships-has_one)
* [has_many](#relationships-has_many)
* [many_to_many](#relationships-many_to_many)
* [belongs_to](#relationships-belongs_to)
### Examples
```
relationships do
belongs_to :post, MyApp.Post do
primary_key? true
end
belongs_to :category, MyApp.Category do
primary_key? true
end
end
```
```
relationships do
belongs_to :author, MyApp.Author
many_to_many :categories, MyApp.Category do
through MyApp.PostCategory
destination_attribute_on_join_resource :category_id
source_attribute_on_join_resource :post_id
end
end
```
```
relationships do
has_many :posts, MyApp.Post do
destination_attribute :author_id
end
has_many :composite_key_posts, MyApp.CompositeKeyPost do
destination_attribute :author_id
end
end
```
## relationships.has_one
```elixir
has_one name, destination
```
Declares a `has_one` relationship. In a relational database, the foreign key would be on the *other* table.
Generally speaking, a `has_one` also implies that the destination table is unique on that foreign key.
See the [relationships guide](/documentation/topics/relationships.md) for more.
### Examples
```
# In a resource called `Word`
has_one :dictionary_entry, DictionaryEntry do
source_attribute :text
destination_attribute :word_text
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-name" href="#relationships-has_one-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the relationship
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-destination" href="#relationships-has_one-destination">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
destination
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The destination resource
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-manual" href="#relationships-has_one-manual">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
manual
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A module that implements `Ash.Resource.ManualRelationship`. Also accepts a 2 argument function that takes the source records and the context.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-no_attributes?" href="#relationships-has_one-no_attributes?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
no_attributes?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
All existing entities are considered related, i.e this relationship is not based on any fields, and `source_attribute` and `destination_attribute` are ignored. See the See the [relationships guide](/documentation/topics/relationships.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-allow_nil?" href="#relationships-has_one-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Marks the relationship as required. Has no effect on validations, but can inform extensions that there will always be a related entity.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-from_many?" href="#relationships-has_one-from_many?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
from_many?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Signal that this relationship is actually a `has_many` where the first record is given via the `sort`. This will allow data layers to properly deduplicate when necessary.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-description" href="#relationships-has_one-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the relationship
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-destination_attribute" href="#relationships-has_one-destination_attribute">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
destination_attribute
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The attribute on the related resource that should match the `source_attribute` configured on this resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-validate_destination_attribute?" href="#relationships-has_one-validate_destination_attribute?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
validate_destination_attribute?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not to validate that the destination field exists on the destination resource
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-source_attribute" href="#relationships-has_one-source_attribute">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
source_attribute
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
<code class="inline">:id</code>
</td>
<td style="text-align: left" colspan=2>
The field on this resource that should match the `destination_attribute` on the related resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-relationship_context" href="#relationships-has_one-relationship_context">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_context
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Context to be set on any queries or changesets generated for managing or querying this relationship.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-private?" href="#relationships-has_one-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the relationship will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-not_found_message" href="#relationships-has_one-not_found_message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
not_found_message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A message to show if there is a conflict with this relationship in the database on update or create, or when managing relationships.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-writable?" href="#relationships-has_one-writable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
writable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the relationship may be managed.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-read_action" href="#relationships-has_one-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action on the destination resource to use when loading data and filtering.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-api" href="#relationships-has_one-api">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
api
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The API module to use when working with the related entity.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-filter" href="#relationships-has_one-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A filter to be applied when reading the relationship.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-filterable?" href="#relationships-has_one-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
If set to `false`, the relationship will not be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-sort" href="#relationships-has_one-sort">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sort
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A sort statement to be applied when loading the relationship.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-could_be_related_at_creation?" href="#relationships-has_one-could_be_related_at_creation?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
could_be_related_at_creation?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not related values may exist for this relationship at creation.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_one-violation_message" href="#relationships-has_one-violation_message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
violation_message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A message to show if there is a conflict with this relationship in the database on destroy.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Relationships.HasOne`
## relationships.has_many
```elixir
has_many name, destination
```
Declares a `has_many` relationship. There can be any number of related entities.
See the [relationships guide](/documentation/topics/relationships.md) for more.
### Examples
```
# In a resource called `Word`
has_many :definitions, DictionaryDefinition do
source_attribute :text
destination_attribute :word_text
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-name" href="#relationships-has_many-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the relationship
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-destination" href="#relationships-has_many-destination">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
destination
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The destination resource
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-manual" href="#relationships-has_many-manual">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
manual
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A module that implements `Ash.Resource.ManualRelationship`. Also accepts a 2 argument function that takes the source records and the context.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-no_attributes?" href="#relationships-has_many-no_attributes?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
no_attributes?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
All existing entities are considered related, i.e this relationship is not based on any fields, and `source_attribute` and `destination_attribute` are ignored. See the See the [relationships guide](/documentation/topics/relationships.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-description" href="#relationships-has_many-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the relationship
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-destination_attribute" href="#relationships-has_many-destination_attribute">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
destination_attribute
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The attribute on the related resource that should match the `source_attribute` configured on this resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-validate_destination_attribute?" href="#relationships-has_many-validate_destination_attribute?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
validate_destination_attribute?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not to validate that the destination field exists on the destination resource
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-source_attribute" href="#relationships-has_many-source_attribute">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
source_attribute
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
<code class="inline">:id</code>
</td>
<td style="text-align: left" colspan=2>
The field on this resource that should match the `destination_attribute` on the related resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-relationship_context" href="#relationships-has_many-relationship_context">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_context
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Context to be set on any queries or changesets generated for managing or querying this relationship.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-private?" href="#relationships-has_many-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the relationship will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-not_found_message" href="#relationships-has_many-not_found_message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
not_found_message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A message to show if there is a conflict with this relationship in the database on update or create, or when managing relationships.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-writable?" href="#relationships-has_many-writable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
writable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the relationship may be managed.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-read_action" href="#relationships-has_many-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action on the destination resource to use when loading data and filtering.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-api" href="#relationships-has_many-api">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
api
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The API module to use when working with the related entity.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-filter" href="#relationships-has_many-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A filter to be applied when reading the relationship.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-filterable?" href="#relationships-has_many-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
If set to `false`, the relationship will not be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-sort" href="#relationships-has_many-sort">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sort
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A sort statement to be applied when loading the relationship.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-could_be_related_at_creation?" href="#relationships-has_many-could_be_related_at_creation?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
could_be_related_at_creation?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not related values may exist for this relationship at creation.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-has_many-violation_message" href="#relationships-has_many-violation_message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
violation_message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A message to show if there is a conflict with this relationship in the database on destroy.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Relationships.HasMany`
## relationships.many_to_many
```elixir
many_to_many name, destination
```
Declares a `many_to_many` relationship. Many to many relationships require a join resource.
A join resource is a resource that consists of a relationship to the source and destination of the many to many.
See the [relationships guide](/documentation/topics/relationships.md) for more.
### Examples
```
# In a resource called `Word`
many_to_many :books, Book do
through BookWord
source_attribute :text
source_attribute_on_join_resource :word_text
destination_attribute :id
destination_attribute_on_join_resource :book_id
end
# And in `BookWord` (the join resource)
belongs_to :book, Book, primary_key?: true, allow_nil?: false
belongs_to :word, Word, primary_key?: true, allow_nil?: false
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-name" href="#relationships-many_to_many-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the relationship
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-destination" href="#relationships-many_to_many-destination">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
destination
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The destination resource
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-source_attribute_on_join_resource" href="#relationships-many_to_many-source_attribute_on_join_resource">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
source_attribute_on_join_resource
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The attribute on the join resource that should line up with `source_attribute` on this resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-destination_attribute_on_join_resource" href="#relationships-many_to_many-destination_attribute_on_join_resource">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
destination_attribute_on_join_resource
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The attribute on the join resource that should line up with `destination_attribute` on the related resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-through" href="#relationships-many_to_many-through">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
through
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The resource to use as the join resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-join_relationship" href="#relationships-many_to_many-join_relationship">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
join_relationship
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The has_many relationship to the join resource. Defaults to <relationship_name>_join_assoc
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-description" href="#relationships-many_to_many-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the relationship
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-destination_attribute" href="#relationships-many_to_many-destination_attribute">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
destination_attribute
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
<code class="inline">:id</code>
</td>
<td style="text-align: left" colspan=2>
The attribute on the related resource that should match the `source_attribute` configured on this resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-validate_destination_attribute?" href="#relationships-many_to_many-validate_destination_attribute?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
validate_destination_attribute?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not to validate that the destination field exists on the destination resource
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-source_attribute" href="#relationships-many_to_many-source_attribute">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
source_attribute
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
<code class="inline">:id</code>
</td>
<td style="text-align: left" colspan=2>
The field on this resource that should match the `destination_attribute` on the related resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-relationship_context" href="#relationships-many_to_many-relationship_context">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_context
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Context to be set on any queries or changesets generated for managing or querying this relationship.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-private?" href="#relationships-many_to_many-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the relationship will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-not_found_message" href="#relationships-many_to_many-not_found_message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
not_found_message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A message to show if there is a conflict with this relationship in the database on update or create, or when managing relationships.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-writable?" href="#relationships-many_to_many-writable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
writable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the relationship may be managed.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-read_action" href="#relationships-many_to_many-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action on the destination resource to use when loading data and filtering.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-api" href="#relationships-many_to_many-api">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
api
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The API module to use when working with the related entity.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-filter" href="#relationships-many_to_many-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A filter to be applied when reading the relationship.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-filterable?" href="#relationships-many_to_many-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
If set to `false`, the relationship will not be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-sort" href="#relationships-many_to_many-sort">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sort
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A sort statement to be applied when loading the relationship.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-could_be_related_at_creation?" href="#relationships-many_to_many-could_be_related_at_creation?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
could_be_related_at_creation?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not related values may exist for this relationship at creation.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-many_to_many-violation_message" href="#relationships-many_to_many-violation_message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
violation_message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A message to show if there is a conflict with this relationship in the database on destroy.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Relationships.ManyToMany`
## relationships.belongs_to
```elixir
belongs_to name, destination
```
Declares a `belongs_to` relationship. In a relational database, the foreign key would be on the *source* table.
This creates a field on the resource with the corresponding name and type, unless `define_attribute?: false` is provided.
See the [relationships guide](/documentation/topics/relationships.md) for more.
### Examples
```
# In a resource called `Word`
belongs_to :dictionary_entry, DictionaryEntry do
source_attribute :text,
destination_attribute :word_text
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-name" href="#relationships-belongs_to-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the relationship
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-destination" href="#relationships-belongs_to-destination">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
destination
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The destination resource
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-primary_key?" href="#relationships-belongs_to-primary_key?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
primary_key?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether the generated attribute is, or is part of, the primary key of a resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-allow_nil?" href="#relationships-belongs_to-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether this relationship must always be present, e.g: must be included on creation, and never removed (it may be modified). The generated attribute will not allow nil values.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-attribute_writable?" href="#relationships-belongs_to-attribute_writable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
attribute_writable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether the generated attribute will be marked as public & writable.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-define_attribute?" href="#relationships-belongs_to-define_attribute?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
define_attribute?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
If set to `false` an attribute is not created on the resource for this relationship, and one must be manually added in `attributes`, invalidating many other options.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-attribute_type" href="#relationships-belongs_to-attribute_type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
attribute_type
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
<code class="inline">:uuid</code>
</td>
<td style="text-align: left" colspan=2>
The type of the generated created attribute. See `Ash.Type` for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-description" href="#relationships-belongs_to-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the relationship
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-destination_attribute" href="#relationships-belongs_to-destination_attribute">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
destination_attribute
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
<code class="inline">:id</code>
</td>
<td style="text-align: left" colspan=2>
The attribute on the related resource that should match the `source_attribute` configured on this resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-validate_destination_attribute?" href="#relationships-belongs_to-validate_destination_attribute?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
validate_destination_attribute?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not to validate that the destination field exists on the destination resource
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-source_attribute" href="#relationships-belongs_to-source_attribute">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
source_attribute
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field on this resource that should match the `destination_attribute` on the related resource. - Defaults to <name>_id
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-relationship_context" href="#relationships-belongs_to-relationship_context">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_context
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Context to be set on any queries or changesets generated for managing or querying this relationship.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-private?" href="#relationships-belongs_to-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the relationship will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-not_found_message" href="#relationships-belongs_to-not_found_message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
not_found_message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A message to show if there is a conflict with this relationship in the database on update or create, or when managing relationships.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-writable?" href="#relationships-belongs_to-writable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
writable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the relationship may be managed.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-read_action" href="#relationships-belongs_to-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action on the destination resource to use when loading data and filtering.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-api" href="#relationships-belongs_to-api">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
api
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The API module to use when working with the related entity.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-filter" href="#relationships-belongs_to-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A filter to be applied when reading the relationship.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-filterable?" href="#relationships-belongs_to-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
If set to `false`, the relationship will not be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-sort" href="#relationships-belongs_to-sort">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sort
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A sort statement to be applied when loading the relationship.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="relationships-belongs_to-violation_message" href="#relationships-belongs_to-violation_message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
violation_message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A message to show if there is a conflict with this relationship in the database on destroy.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Relationships.BelongsTo`
## actions
A section for declaring resource actions.
All manipulation of data through the underlying data layer happens through actions.
There are four types of action: `create`, `read`, `update`, and `destroy`. You may
recognize these from the acronym `CRUD`. You can have multiple actions of the same
type, as long as they have different names. This is the primary mechanism for customizing
your resources to conform to your business logic. It is normal and expected to have
multiple actions of each type in a large application.
### Nested DSLs
* [action](#actions-action)
* argument
* [create](#actions-create)
* change
* validate
* argument
* metadata
* [read](#actions-read)
* argument
* prepare
* pagination
* metadata
* [update](#actions-update)
* change
* validate
* metadata
* argument
* [destroy](#actions-destroy)
* change
* validate
* metadata
* argument
### Examples
```
actions do
create :signup do
argument :password, :string
argument :password_confirmation, :string
validate confirm(:password, :password_confirmation)
change {MyApp.HashPassword, []} # A custom implemented Change
end
read :me do
# An action that auto filters to only return the user for the current user
filter [id: actor(:id)]
end
update :update do
accept [:first_name, :last_name]
end
destroy do
change set_attribute(:deleted_at, &DateTime.utc_now/0)
# This tells it that even though this is a delete action, it
# should be treated like an update because `deleted_at` is set.
# This should be coupled with a `base_filter` on the resource
# or with the read actions having a `filter` for `is_nil: :deleted_at`
soft? true
end
end
```
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-defaults" href="#actions-defaults">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
defaults
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(:create | :read | :update | :destroy)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Creates a simple action of each specified type, with the same name as the type. These will be `primary?` unless one already exists for that type. Embedded resources, however, have a default of all resource types.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-default_accept" href="#actions-default_accept">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default_accept
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A default value for the `accept` option for each action. Defaults to all public attributes.
</td>
</tr>
</tbody>
</table>
## actions.action
```elixir
action name, returns
```
Declares a generic action. A combination of arguments, a return type and a run function.
For calling this action, see the `Ash.Api` documentation.
### Nested DSLs
* [argument](#actions-action-argument)
### Examples
```
action :top_user_emails, {:array, :string} do
argument :limit, :integer, default: 10, allow_nil?: false
run fn input, context ->
with {:ok, top_users} <- top_users(input.limit) do
{:ok, Enum.map(top_users, &(&1.email))}
end
end
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-action-name" href="#actions-action-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the action
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-returns" href="#actions-action-returns">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
returns
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The return type of the action. See `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-action-constraints" href="#actions-action-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Constraints for the return type. See the [constriants topic](/documentation/topics/constraints.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-allow_nil?" href="#actions-action-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Wether or not the action can return nil. Unlike attributes & arguments, this defaults to `false`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-run" href="#actions-action-run">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
run
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-primary?" href="#actions-action-primary?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
primary?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not this action should be used when no action is specified by the caller.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-description" href="#actions-action-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the action
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-transaction?" href="#actions-action-transaction?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
transaction?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Whether or not the action should be run in transactions. Reads default to false, while create/update/destroy actions default to `true`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-touches_resources" href="#actions-action-touches_resources">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
touches_resources
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of resources that the action may touch, used when building transactions.
</td>
</tr>
</tbody>
</table>
## actions.action.argument
```elixir
argument name, type
```
Declares an argument on the action
### Examples
```
argument :password_confirmation, :string
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-action-argument-name" href="#actions-action-argument-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the argument
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-argument-type" href="#actions-action-argument-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the argument. See `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-action-argument-description" href="#actions-action-argument-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the argument.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-argument-constraints" href="#actions-action-argument-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Constraints to provide to the type when casting the value. For more information, see [the constraints topic](/documentation/topics/constraints.md).
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-argument-allow_nil?" href="#actions-action-argument-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument value may be nil (or may be not provided). If nil value is given error is raised.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-argument-private?" href="#actions-action-argument-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument should be suppliable by the client.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-argument-sensitive?" href="#actions-action-argument-sensitive?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sensitive?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument value contains sensitive information, like PII. See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-action-argument-default" href="#actions-action-argument-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The default value for the argument to take. It can be a zero argument function e.g `&MyMod.my_fun/0` or a value
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Actions.Argument`
### Introspection
Target: `Ash.Resource.Actions.Action`
## actions.create
```elixir
create name
```
Declares a `create` action. For calling this action, see the `Ash.Api` documentation.
### Nested DSLs
* [change](#actions-create-change)
* [validate](#actions-create-validate)
* [argument](#actions-create-argument)
* [metadata](#actions-create-metadata)
### Examples
```
create :register do
primary? true
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-create-name" href="#actions-create-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the action
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-create-allow_nil_input" href="#actions-create-allow_nil_input">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil_input
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of attributes that would normally be required, but should not be for this action. They will still be validated just before the record is created.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-manual" href="#actions-create-manual">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
manual
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Override the creation behavior. Accepts a module or module and opts, or a function that takes the changeset and context. See the [manual actions guide](/documentation/topics/manual-actions.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-upsert?" href="#actions-create-upsert?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
upsert?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Forces all uses of this action to be treated as an upsert.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-upsert_identity" href="#actions-create-upsert_identity">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
upsert_identity
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The identity to use for the upsert. Cannot be overriden by the caller. Ignored if `upsert?` is not set to `true`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-upsert_fields" href="#actions-create-upsert_fields">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
upsert_fields
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The fields to overwrite in the case of an upsert. If not provided, all fields except for fields set by defaults will be overwritten.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-primary?" href="#actions-create-primary?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
primary?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not this action should be used when no action is specified by the caller.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-description" href="#actions-create-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the action
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-transaction?" href="#actions-create-transaction?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
transaction?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Whether or not the action should be run in transactions. Reads default to false, while create/update/destroy actions default to `true`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-touches_resources" href="#actions-create-touches_resources">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
touches_resources
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of resources that the action may touch, used when building transactions.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-accept" href="#actions-create-accept">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
accept
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">:all | list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The list of attributes to accept. Defaults to all attributes on the resource
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-delay_global_validations?" href="#actions-create-delay_global_validations?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
delay_global_validations?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If true, global validations will be done in a `before_action` hook, regardless of their configuration on the resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-skip_global_validations?" href="#actions-create-skip_global_validations?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
skip_global_validations?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If true, global validations will be skipped. Useful for manual actions.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-reject" href="#actions-create-reject">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
reject
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">:all | list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of attributes not to accept. If this is specified along with `accept`, these are removed from the `accept` list.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-require_attributes" href="#actions-create-require_attributes">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
require_attributes
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of attributes that would normally `allow_nil?`, to require for this action. No need to include attributes that already do not allow nil?
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-error_handler" href="#actions-create-error_handler">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
error_handler
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">mfa</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Sets the error handler on the changeset. See `Ash.Changeset.handle_errors/2` for more
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-manual?" href="#actions-create-manual?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
manual?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Instructs Ash to *skip* the actual update/create/destroy step at the data layer. See the [manual actions guide](/documentation/topics/manual-actions.md) for more.
</td>
</tr>
</tbody>
</table>
## actions.create.change
```elixir
change change
```
A change to be applied to the changeset.
See `Ash.Resource.Change` for more.
### Examples
```
change relate_actor(:reporter)
```
```
change {MyCustomChange, :foo}
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-create-change-change" href="#actions-create-change-change">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
change
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The module and options for a change. Also accepts a function that takes the changeset and the context. See `Ash.Resource.Change.Builtins` for builtin changes.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-create-change-only_when_valid?" href="#actions-create-change-only_when_valid?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
only_when_valid?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If the change should only be run on valid changes. By default, all changes are run unless stated otherwise here.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-change-description" href="#actions-create-change-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the change
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-change-where" href="#actions-create-change-where">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
where
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list((any -> any) | module)</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Validations that should pass in order for this validation to apply. These validations failing will result in this validation being ignored.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Change`
## actions.create.validate
```elixir
validate validation
```
Declares a validation to be applied to the changeset.
See `Ash.Resource.Validation` for more.
### Examples
```
validate changing(:email)
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-create-validate-validation" href="#actions-create-validate-validation">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
validation
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">(any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The module (or module and opts) that implements the `Ash.Resource.Validation` behaviour. Also accepts a one argument function that takes the changeset.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-create-validate-where" href="#actions-create-validate-where">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
where
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list((any -> any) | module) | (any -> any) | module</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Validations that should pass in order for this validation to apply. Any of these validations failing will result in this validation being ignored.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-validate-only_when_valid?" href="#actions-create-validate-only_when_valid?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
only_when_valid?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If the validation should only run on valid changes. Useful for expensive validations or validations that depend on valid data.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-validate-message" href="#actions-create-validate-message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
If provided, overrides any message set by the validation error
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-validate-description" href="#actions-create-validate-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the validation
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-validate-before_action?" href="#actions-create-validate-before_action?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
before_action?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If set to `true`, the validation will be run in a before_action hook
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Validation`
## actions.create.argument
```elixir
argument name, type
```
Declares an argument on the action
### Examples
```
argument :password_confirmation, :string
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-create-argument-name" href="#actions-create-argument-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the argument
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-argument-type" href="#actions-create-argument-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the argument. See `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-create-argument-description" href="#actions-create-argument-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the argument.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-argument-constraints" href="#actions-create-argument-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Constraints to provide to the type when casting the value. For more information, see [the constraints topic](/documentation/topics/constraints.md).
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-argument-allow_nil?" href="#actions-create-argument-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument value may be nil (or may be not provided). If nil value is given error is raised.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-argument-private?" href="#actions-create-argument-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument should be suppliable by the client.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-argument-sensitive?" href="#actions-create-argument-sensitive?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sensitive?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument value contains sensitive information, like PII. See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-argument-default" href="#actions-create-argument-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The default value for the argument to take. It can be a zero argument function e.g `&MyMod.my_fun/0` or a value
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Actions.Argument`
## actions.create.metadata
```elixir
metadata name, type
```
A special kind of attribute that is only added to specific actions. Nothing sets this value, it must be set in a custom
change via `Ash.Resource.Info.put_metadata/3`.
### Examples
```
metadata :api_token, :string, allow_nil?: false
```
```
metadata :operation_id, :string, allow_nil?: false
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-create-metadata-name" href="#actions-create-metadata-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the metadata
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-metadata-type" href="#actions-create-metadata-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the metadata. See `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-create-metadata-constraints" href="#actions-create-metadata-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Type constraints on the metadata
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-metadata-description" href="#actions-create-metadata-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the metadata.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-metadata-allow_nil?" href="#actions-create-metadata-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the metadata may return `nil`
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-create-metadata-default" href="#actions-create-metadata-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The default value for the metadata to take. It can be a zero argument function e.g `&MyMod.my_fun/0` or a value
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Actions.Metadata`
### Introspection
Target: `Ash.Resource.Actions.Create`
## actions.read
```elixir
read name
```
Declares a `read` action. For calling this action, see the `Ash.Api` documentation.
### Nested DSLs
* [argument](#actions-read-argument)
* [prepare](#actions-read-prepare)
* [pagination](#actions-read-pagination)
* [metadata](#actions-read-metadata)
### Examples
```
read :read_all do
primary? true
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-read-name" href="#actions-read-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the action
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-read-filter" href="#actions-read-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A filter template that will be applied whenever the action is used. See `Ash.Filter` for more on templates
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-manual" href="#actions-read-manual">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
manual
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(any, any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Delegates running of the query to the provided module. Accepts a module or module and opts, or a function that takes the changeset and context. See the [manual actions guide](/documentation/topics/manual-actions.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-get?" href="#actions-read-get?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
get?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Expresses that this action innately only returns a single result. Used by extensions to validate and/or modify behavior. Causes code interfaces to return a single value instead of a list. See the [code interface guide](/documentation/topics/code-interface.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-modify_query" href="#actions-read-modify_query">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
modify_query
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">mfa | (any, any -> any)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Allows direct manipulation of the data layer query via an MFA. The ash query and the data layer query will be provided as additional arguments. The result must be `{:ok, new_data_layer_query} | {:error, error}`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-get_by" href="#actions-read-get_by">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
get_by
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom) | atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A helper to automatically generate a "get by X" action. Sets `get?` to true, add args for each of the specified fields, and adds a filter for each of the arguments.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-primary?" href="#actions-read-primary?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
primary?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not this action should be used when no action is specified by the caller.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-description" href="#actions-read-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the action
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-transaction?" href="#actions-read-transaction?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
transaction?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Whether or not the action should be run in transactions. Reads default to false, while create/update/destroy actions default to `true`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-touches_resources" href="#actions-read-touches_resources">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
touches_resources
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of resources that the action may touch, used when building transactions.
</td>
</tr>
</tbody>
</table>
## actions.read.argument
```elixir
argument name, type
```
Declares an argument on the action
### Examples
```
argument :password_confirmation, :string
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-read-argument-name" href="#actions-read-argument-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the argument
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-argument-type" href="#actions-read-argument-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the argument. See `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-read-argument-description" href="#actions-read-argument-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the argument.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-argument-constraints" href="#actions-read-argument-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Constraints to provide to the type when casting the value. For more information, see [the constraints topic](/documentation/topics/constraints.md).
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-argument-allow_nil?" href="#actions-read-argument-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument value may be nil (or may be not provided). If nil value is given error is raised.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-argument-private?" href="#actions-read-argument-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument should be suppliable by the client.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-argument-sensitive?" href="#actions-read-argument-sensitive?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sensitive?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument value contains sensitive information, like PII. See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-argument-default" href="#actions-read-argument-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The default value for the argument to take. It can be a zero argument function e.g `&MyMod.my_fun/0` or a value
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Actions.Argument`
## actions.read.prepare
```elixir
prepare preparation
```
Declares a preparation, which can be used to prepare a query for a read action.
### Examples
```
prepare build(sort: [:foo, :bar])
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-read-prepare-preparation" href="#actions-read-prepare-preparation">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
preparation
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The module and options for a preparation. Also accepts functions take the query and the context.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Preparation`
## actions.read.pagination
Adds pagination options to a resource
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-read-pagination-keyset?" href="#actions-read-pagination-keyset?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
keyset?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not keyset based pagination is supported
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-pagination-offset?" href="#actions-read-pagination-offset?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
offset?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not offset based pagination is supported
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-pagination-default_limit" href="#actions-read-pagination-default_limit">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default_limit
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">pos_integer</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The default page size to apply, if one is not supplied
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-pagination-countable" href="#actions-read-pagination-countable">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
countable
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">true | false | :by_default</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether not a returned page will have a full count of all records. Use `:by_default` to do it automatically.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-pagination-max_page_size" href="#actions-read-pagination-max_page_size">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
max_page_size
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">pos_integer</code>
</td>
<td style="text-align: left">
<code class="inline">250</code>
</td>
<td style="text-align: left" colspan=2>
The maximum amount of records that can be requested in a single page
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-pagination-required?" href="#actions-read-pagination-required?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
required?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not pagination can be disabled. Only relevant if some pagination configuration is supplied.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Actions.Read.Pagination`
## actions.read.metadata
```elixir
metadata name, type
```
A special kind of attribute that is only added to specific actions. Nothing sets this value, it must be set in a custom
change via `Ash.Resource.Info.put_metadata/3`.
### Examples
```
metadata :api_token, :string, allow_nil?: false
```
```
metadata :operation_id, :string, allow_nil?: false
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-read-metadata-name" href="#actions-read-metadata-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the metadata
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-metadata-type" href="#actions-read-metadata-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the metadata. See `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-read-metadata-constraints" href="#actions-read-metadata-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Type constraints on the metadata
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-metadata-description" href="#actions-read-metadata-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the metadata.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-metadata-allow_nil?" href="#actions-read-metadata-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the metadata may return `nil`
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-read-metadata-default" href="#actions-read-metadata-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The default value for the metadata to take. It can be a zero argument function e.g `&MyMod.my_fun/0` or a value
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Actions.Metadata`
### Introspection
Target: `Ash.Resource.Actions.Read`
## actions.update
```elixir
update name
```
Declares a `update` action. For calling this action, see the `Ash.Api` documentation.
### Nested DSLs
* [change](#actions-update-change)
* [validate](#actions-update-validate)
* [metadata](#actions-update-metadata)
* [argument](#actions-update-argument)
### Examples
```
update :flag_for_review, primary?: true
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-update-name" href="#actions-update-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the action
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-update-manual" href="#actions-update-manual">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
manual
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Override the update behavior. Accepts a module or module and opts, or a function that takes the changeset and context. See the [manual actions guide](/documentation/topics/manual-actions.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-primary?" href="#actions-update-primary?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
primary?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not this action should be used when no action is specified by the caller.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-description" href="#actions-update-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the action
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-transaction?" href="#actions-update-transaction?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
transaction?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Whether or not the action should be run in transactions. Reads default to false, while create/update/destroy actions default to `true`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-touches_resources" href="#actions-update-touches_resources">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
touches_resources
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of resources that the action may touch, used when building transactions.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-accept" href="#actions-update-accept">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
accept
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">:all | list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The list of attributes to accept. Defaults to all attributes on the resource
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-delay_global_validations?" href="#actions-update-delay_global_validations?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
delay_global_validations?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If true, global validations will be done in a `before_action` hook, regardless of their configuration on the resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-skip_global_validations?" href="#actions-update-skip_global_validations?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
skip_global_validations?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If true, global validations will be skipped. Useful for manual actions.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-reject" href="#actions-update-reject">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
reject
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">:all | list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of attributes not to accept. If this is specified along with `accept`, these are removed from the `accept` list.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-require_attributes" href="#actions-update-require_attributes">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
require_attributes
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of attributes that would normally `allow_nil?`, to require for this action. No need to include attributes that already do not allow nil?
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-error_handler" href="#actions-update-error_handler">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
error_handler
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">mfa</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Sets the error handler on the changeset. See `Ash.Changeset.handle_errors/2` for more
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-manual?" href="#actions-update-manual?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
manual?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Instructs Ash to *skip* the actual update/create/destroy step at the data layer. See the [manual actions guide](/documentation/topics/manual-actions.md) for more.
</td>
</tr>
</tbody>
</table>
## actions.update.change
```elixir
change change
```
A change to be applied to the changeset.
See `Ash.Resource.Change` for more.
### Examples
```
change relate_actor(:reporter)
```
```
change {MyCustomChange, :foo}
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-update-change-change" href="#actions-update-change-change">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
change
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The module and options for a change. Also accepts a function that takes the changeset and the context. See `Ash.Resource.Change.Builtins` for builtin changes.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-update-change-only_when_valid?" href="#actions-update-change-only_when_valid?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
only_when_valid?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If the change should only be run on valid changes. By default, all changes are run unless stated otherwise here.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-change-description" href="#actions-update-change-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the change
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-change-where" href="#actions-update-change-where">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
where
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list((any -> any) | module)</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Validations that should pass in order for this validation to apply. These validations failing will result in this validation being ignored.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Change`
## actions.update.validate
```elixir
validate validation
```
Declares a validation to be applied to the changeset.
See `Ash.Resource.Validation` for more.
### Examples
```
validate changing(:email)
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-update-validate-validation" href="#actions-update-validate-validation">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
validation
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">(any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The module (or module and opts) that implements the `Ash.Resource.Validation` behaviour. Also accepts a one argument function that takes the changeset.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-update-validate-where" href="#actions-update-validate-where">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
where
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list((any -> any) | module) | (any -> any) | module</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Validations that should pass in order for this validation to apply. Any of these validations failing will result in this validation being ignored.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-validate-only_when_valid?" href="#actions-update-validate-only_when_valid?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
only_when_valid?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If the validation should only run on valid changes. Useful for expensive validations or validations that depend on valid data.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-validate-message" href="#actions-update-validate-message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
If provided, overrides any message set by the validation error
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-validate-description" href="#actions-update-validate-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the validation
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-validate-before_action?" href="#actions-update-validate-before_action?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
before_action?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If set to `true`, the validation will be run in a before_action hook
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Validation`
## actions.update.metadata
```elixir
metadata name, type
```
A special kind of attribute that is only added to specific actions. Nothing sets this value, it must be set in a custom
change via `Ash.Resource.Info.put_metadata/3`.
### Examples
```
metadata :api_token, :string, allow_nil?: false
```
```
metadata :operation_id, :string, allow_nil?: false
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-update-metadata-name" href="#actions-update-metadata-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the metadata
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-metadata-type" href="#actions-update-metadata-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the metadata. See `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-update-metadata-constraints" href="#actions-update-metadata-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Type constraints on the metadata
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-metadata-description" href="#actions-update-metadata-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the metadata.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-metadata-allow_nil?" href="#actions-update-metadata-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the metadata may return `nil`
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-metadata-default" href="#actions-update-metadata-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The default value for the metadata to take. It can be a zero argument function e.g `&MyMod.my_fun/0` or a value
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Actions.Metadata`
## actions.update.argument
```elixir
argument name, type
```
Declares an argument on the action
### Examples
```
argument :password_confirmation, :string
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-update-argument-name" href="#actions-update-argument-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the argument
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-argument-type" href="#actions-update-argument-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the argument. See `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-update-argument-description" href="#actions-update-argument-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the argument.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-argument-constraints" href="#actions-update-argument-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Constraints to provide to the type when casting the value. For more information, see [the constraints topic](/documentation/topics/constraints.md).
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-argument-allow_nil?" href="#actions-update-argument-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument value may be nil (or may be not provided). If nil value is given error is raised.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-argument-private?" href="#actions-update-argument-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument should be suppliable by the client.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-argument-sensitive?" href="#actions-update-argument-sensitive?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sensitive?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument value contains sensitive information, like PII. See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-update-argument-default" href="#actions-update-argument-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The default value for the argument to take. It can be a zero argument function e.g `&MyMod.my_fun/0` or a value
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Actions.Argument`
### Introspection
Target: `Ash.Resource.Actions.Update`
## actions.destroy
```elixir
destroy name
```
Declares a `destroy` action. For calling this action, see the `Ash.Api` documentation.
### Nested DSLs
* [change](#actions-destroy-change)
* [validate](#actions-destroy-validate)
* [metadata](#actions-destroy-metadata)
* [argument](#actions-destroy-argument)
### Examples
```
destroy :soft_delete do
primary? true
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-destroy-name" href="#actions-destroy-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the action
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-destroy-soft?" href="#actions-destroy-soft?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
soft?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If specified, the destroy action behaves as an update internally
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-manual" href="#actions-destroy-manual">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
manual
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Override the update behavior. Accepts a module or module and opts, or a function that takes the changeset and context. See the [manual actions guide](/documentation/topics/manual-actions.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-primary?" href="#actions-destroy-primary?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
primary?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not this action should be used when no action is specified by the caller.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-description" href="#actions-destroy-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the action
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-transaction?" href="#actions-destroy-transaction?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
transaction?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Whether or not the action should be run in transactions. Reads default to false, while create/update/destroy actions default to `true`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-touches_resources" href="#actions-destroy-touches_resources">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
touches_resources
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of resources that the action may touch, used when building transactions.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-accept" href="#actions-destroy-accept">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
accept
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">:all | list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The list of attributes to accept. Defaults to all attributes on the resource
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-delay_global_validations?" href="#actions-destroy-delay_global_validations?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
delay_global_validations?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If true, global validations will be done in a `before_action` hook, regardless of their configuration on the resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-skip_global_validations?" href="#actions-destroy-skip_global_validations?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
skip_global_validations?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If true, global validations will be skipped. Useful for manual actions.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-reject" href="#actions-destroy-reject">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
reject
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">:all | list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of attributes not to accept. If this is specified along with `accept`, these are removed from the `accept` list.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-require_attributes" href="#actions-destroy-require_attributes">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
require_attributes
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of attributes that would normally `allow_nil?`, to require for this action. No need to include attributes that already do not allow nil?
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-error_handler" href="#actions-destroy-error_handler">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
error_handler
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">mfa</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Sets the error handler on the changeset. See `Ash.Changeset.handle_errors/2` for more
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-manual?" href="#actions-destroy-manual?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
manual?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Instructs Ash to *skip* the actual update/create/destroy step at the data layer. See the [manual actions guide](/documentation/topics/manual-actions.md) for more.
</td>
</tr>
</tbody>
</table>
## actions.destroy.change
```elixir
change change
```
A change to be applied to the changeset.
See `Ash.Resource.Change` for more.
### Examples
```
change relate_actor(:reporter)
```
```
change {MyCustomChange, :foo}
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-destroy-change-change" href="#actions-destroy-change-change">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
change
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The module and options for a change. Also accepts a function that takes the changeset and the context. See `Ash.Resource.Change.Builtins` for builtin changes.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-destroy-change-only_when_valid?" href="#actions-destroy-change-only_when_valid?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
only_when_valid?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If the change should only be run on valid changes. By default, all changes are run unless stated otherwise here.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-change-description" href="#actions-destroy-change-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the change
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-change-where" href="#actions-destroy-change-where">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
where
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list((any -> any) | module)</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Validations that should pass in order for this validation to apply. These validations failing will result in this validation being ignored.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Change`
## actions.destroy.validate
```elixir
validate validation
```
Declares a validation to be applied to the changeset.
See `Ash.Resource.Validation` for more.
### Examples
```
validate changing(:email)
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-destroy-validate-validation" href="#actions-destroy-validate-validation">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
validation
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">(any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The module (or module and opts) that implements the `Ash.Resource.Validation` behaviour. Also accepts a one argument function that takes the changeset.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-destroy-validate-where" href="#actions-destroy-validate-where">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
where
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list((any -> any) | module) | (any -> any) | module</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Validations that should pass in order for this validation to apply. Any of these validations failing will result in this validation being ignored.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-validate-only_when_valid?" href="#actions-destroy-validate-only_when_valid?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
only_when_valid?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If the validation should only run on valid changes. Useful for expensive validations or validations that depend on valid data.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-validate-message" href="#actions-destroy-validate-message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
If provided, overrides any message set by the validation error
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-validate-description" href="#actions-destroy-validate-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the validation
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-validate-before_action?" href="#actions-destroy-validate-before_action?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
before_action?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If set to `true`, the validation will be run in a before_action hook
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Validation`
## actions.destroy.metadata
```elixir
metadata name, type
```
A special kind of attribute that is only added to specific actions. Nothing sets this value, it must be set in a custom
change via `Ash.Resource.Info.put_metadata/3`.
### Examples
```
metadata :api_token, :string, allow_nil?: false
```
```
metadata :operation_id, :string, allow_nil?: false
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-destroy-metadata-name" href="#actions-destroy-metadata-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the metadata
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-metadata-type" href="#actions-destroy-metadata-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the metadata. See `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-destroy-metadata-constraints" href="#actions-destroy-metadata-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Type constraints on the metadata
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-metadata-description" href="#actions-destroy-metadata-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the metadata.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-metadata-allow_nil?" href="#actions-destroy-metadata-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the metadata may return `nil`
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-metadata-default" href="#actions-destroy-metadata-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The default value for the metadata to take. It can be a zero argument function e.g `&MyMod.my_fun/0` or a value
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Actions.Metadata`
## actions.destroy.argument
```elixir
argument name, type
```
Declares an argument on the action
### Examples
```
argument :password_confirmation, :string
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-destroy-argument-name" href="#actions-destroy-argument-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the argument
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-argument-type" href="#actions-destroy-argument-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the argument. See `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="actions-destroy-argument-description" href="#actions-destroy-argument-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the argument.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-argument-constraints" href="#actions-destroy-argument-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Constraints to provide to the type when casting the value. For more information, see [the constraints topic](/documentation/topics/constraints.md).
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-argument-allow_nil?" href="#actions-destroy-argument-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument value may be nil (or may be not provided). If nil value is given error is raised.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-argument-private?" href="#actions-destroy-argument-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument should be suppliable by the client.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-argument-sensitive?" href="#actions-destroy-argument-sensitive?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sensitive?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument value contains sensitive information, like PII. See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="actions-destroy-argument-default" href="#actions-destroy-argument-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The default value for the argument to take. It can be a zero argument function e.g `&MyMod.my_fun/0` or a value
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Actions.Argument`
### Introspection
Target: `Ash.Resource.Actions.Destroy`
## code_interface
Functions that will be defined on the Api module to interact with this resource. See the [code interface guide](/documentation/topics/code-interface.md) for more.
### Nested DSLs
* [define](#code_interface-define)
* [define_calculation](#code_interface-define_calculation)
### Examples
```
code_interface do
define_for MyApp.Api
define :create_user, action: :create
define :get_user_by_id, action: :get_by_id, args: [:id], get?: true
end
```
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="code_interface-define_for" href="#code_interface-define_for">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
define_for
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Defines the code interface on the resource module directly, using the provided Api.
</td>
</tr>
</tbody>
</table>
## code_interface.define
```elixir
define name
```
Defines a function with the corresponding name and arguments. See the [code interface guide](/documentation/topics/code-interface.md) for more.
### Examples
```
define :get_user_by_id, action: :get_by_id, args: [:id], get?: true
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="code_interface-define-name" href="#code_interface-define-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the function that will be defined
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="code_interface-define-action" href="#code_interface-define-action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the action that will be called. Defaults to the same name as the function.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="code_interface-define-args" href="#code_interface-define-args">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
args
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom | {:optional, atom})</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Map specific arguments to named inputs. Can provide any argument/attributes that the action allows.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="code_interface-define-not_found_error?" href="#code_interface-define-not_found_error?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
not_found_error?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
If the action or interface is configured with `get?: true`, this determines whether or not an error is raised or `nil` is returned.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="code_interface-define-get?" href="#code_interface-define-get?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
get?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Expects to only receive a single result from a read action, and returns a single result instead of a list. Ignored for other action types.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="code_interface-define-get_by" href="#code_interface-define-get_by">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
get_by
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom) | atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Takes a list of fields and adds those fields as arguments, which will then be used to filter. Sets `get?` to true automatically. Ignored for non-read actions.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="code_interface-define-get_by_identity" href="#code_interface-define-get_by_identity">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
get_by_identity
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Only relevant for read actions. Takes an identity, and gets its field list, performing the same logic as `get_by` once it has the list of fields.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Interface`
## code_interface.define_calculation
```elixir
define_calculation name
```
Defines a function with the corresponding name and arguments, that evaluates a calculation. Use `:_record` to take an instance of a record. See the [code interface guide](/documentation/topics/code-interface.md) for more.
### Examples
```
define_calculation :referral_link, args: [:id]
```
```
define_calculation :referral_link, args: [{:arg, :id}, {:ref, :id}]
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="code_interface-define_calculation-name" href="#code_interface-define_calculation-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the function that will be defined
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="code_interface-define_calculation-calculation" href="#code_interface-define_calculation-calculation">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
calculation
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the calculation that will be evaluated. Defaults to the same name as the function.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="code_interface-define_calculation-args" href="#code_interface-define_calculation-args">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
args
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Supply field or argument values referenced by the calculation, in the form of :name, `{:arg, :name}` and/or `{:ref, :name}`. See the [code interface guide](/documentation/topics/code-interface.md) for more.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.CalculationInterface`
## resource
General resource configuration
### Examples
```
resource do
description "A description of this resource"
base_filter [is_nil: :deleted_at]
end
```
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="resource-description" href="#resource-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A human readable description of the resource, to be used in generated documentation
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="resource-base_filter" href="#resource-base_filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
base_filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A filter statement to be applied to any queries on the resource
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="resource-default_context" href="#resource-default_context">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default_context
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Default context to apply to any queries/changesets generated for this resource.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="resource-trace_name" href="#resource-trace_name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
trace_name
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name to use in traces. Defaults to the short_name stringified. See the [monitoring guide](/documentation/topics/monitoring.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="resource-short_name" href="#resource-short_name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
short_name
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A short identifier for the resource, which should be unique. See the [monitoring guide](/documentation/topics/monitoring.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="resource-plural_name" href="#resource-plural_name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
plural_name
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A pluralized version of the resource short_name. May be used by generators or automated tooling.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="resource-simple_notifiers" href="#resource-simple_notifiers">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
simple_notifiers
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(module)</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A list of notifiers that require no DSL. Can be used to avoid compile time dependencies on notifiers
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="resource-require_primary_key?" href="#resource-require_primary_key?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
require_primary_key?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Allow the resource to be used without any primary key fields. Warning: this option is experimental, and should not be used unless you know what you're doing.
</td>
</tr>
</tbody>
</table>
## identities
Unique identifiers for the resource
### Nested DSLs
* [identity](#identities-identity)
### Examples
```
identities do
identity :full_name, [:first_name, :last_name]
identity :email, [:email]
end
```
## identities.identity
```elixir
identity name, keys
```
Represents a unique constraint on the resource.
See the [identities guide](/documentation/topics/identities.md) for more.
### Examples
```
identity :name, [:name]
```
```
identity :full_name, [:first_name, :last_name]
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="identities-identity-name" href="#identities-identity-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the identity.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="identities-identity-keys" href="#identities-identity-keys">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
keys
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">list(atom) | atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The names of the attributes that uniquely identify this resource.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="identities-identity-eager_check_with" href="#identities-identity-eager_check_with">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
eager_check_with
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Validates that the unique identity provided is unique at validation time, outside of any transactions, using the api module provided.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="identities-identity-pre_check_with" href="#identities-identity-pre_check_with">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
pre_check_with
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
Validates that the unique identity provided is unique in a before_action hook.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="identities-identity-description" href="#identities-identity-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the identity
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="identities-identity-message" href="#identities-identity-message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An error message to use when the unique identity would be violated
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Identity`
## changes
Declare changes that occur on create/update/destroy actions against the resource
See `Ash.Resource.Change` for more.
### Nested DSLs
* [change](#changes-change)
### Examples
```
changes do
change {Mod, [foo: :bar]}
change set_context(%{some: :context})
end
```
## changes.change
```elixir
change change
```
A change to be applied to the changeset.
See `Ash.Resource.Change` for more.
### Examples
```
change relate_actor(:reporter)
```
```
change {MyCustomChange, :foo}
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="changes-change-change" href="#changes-change-change">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
change
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The module and options for a change. Also accepts a function that takes the changeset and the context. See `Ash.Resource.Change.Builtins` for builtin changes.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="changes-change-on" href="#changes-change-on">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
on
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(:create | :update | :destroy) | :create | :update | :destroy</code>
</td>
<td style="text-align: left">
<code class="inline">[:create, :update]</code>
</td>
<td style="text-align: left" colspan=2>
The action types the validation should run on. Destroy actions are omitted by default as most changes don't make sense for a destroy.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="changes-change-only_when_valid?" href="#changes-change-only_when_valid?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
only_when_valid?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If the change should only be run on valid changes. By default, all changes are run unless stated otherwise here.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="changes-change-description" href="#changes-change-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the change
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="changes-change-where" href="#changes-change-where">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
where
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list((any -> any) | module)</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Validations that should pass in order for this validation to apply. These validations failing will result in this validation being ignored.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Change`
## preparations
Declare preparations that occur on all read actions for a given resource
### Nested DSLs
* [prepare](#preparations-prepare)
### Examples
```
preparations do
prepare {Mod, [foo: :bar]}
prepare set_context(%{some: :context})
end
```
## preparations.prepare
```elixir
prepare preparation
```
Declares a preparation, which can be used to prepare a query for a read action.
### Examples
```
prepare build(sort: [:foo, :bar])
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="preparations-prepare-preparation" href="#preparations-prepare-preparation">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
preparation
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The module and options for a preparation. Also accepts functions take the query and the context.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Preparation`
## validations
Declare validations prior to performing actions against the resource
### Nested DSLs
* [validate](#validations-validate)
### Examples
```
validations do
validate {Mod, [foo: :bar]}
validate at_least_one_of_present([:first_name, :last_name])
end
```
## validations.validate
```elixir
validate validation
```
Declares a validation for creates and updates.
See `Ash.Resource.Change` for more.
### Examples
```
validate {Mod, [foo: :bar]}
```
```
validate at_least_one_of_present([:first_name, :last_name])
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="validations-validate-validation" href="#validations-validate-validation">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
validation
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">(any -> any) | module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The module (or module and opts) that implements the `Ash.Resource.Validation` behaviour. Also accepts a one argument function that takes the changeset.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="validations-validate-where" href="#validations-validate-where">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
where
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list((any -> any) | module) | (any -> any) | module</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Validations that should pass in order for this validation to apply. Any of these validations failing will result in this validation being ignored.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="validations-validate-on" href="#validations-validate-on">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
on
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(:create | :update | :destroy) | :create | :update | :destroy</code>
</td>
<td style="text-align: left">
<code class="inline">[:create, :update]</code>
</td>
<td style="text-align: left" colspan=2>
The action types the validation should run on. Many validations don't make sense in the context of deletion, so by default it is not included.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="validations-validate-only_when_valid?" href="#validations-validate-only_when_valid?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
only_when_valid?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If the validation should only run on valid changes. Useful for expensive validations or validations that depend on valid data.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="validations-validate-message" href="#validations-validate-message">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
message
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
If provided, overrides any message set by the validation error
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="validations-validate-description" href="#validations-validate-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the validation
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="validations-validate-before_action?" href="#validations-validate-before_action?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
before_action?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
If set to `true`, the validation will be run in a before_action hook
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Validation`
## aggregates
Declare named aggregates on the resource.
These are aggregates that can be loaded only by name using `Ash.Query.load/2`.
They are also available as top level fields on the resource.
See the [aggregates guide](/documentation/topics/aggregates.md) for more.
### Nested DSLs
* [count](#aggregates-count)
* [exists](#aggregates-exists)
* [first](#aggregates-first)
* [sum](#aggregates-sum)
* [list](#aggregates-list)
* [max](#aggregates-max)
* [min](#aggregates-min)
* [avg](#aggregates-avg)
* [custom](#aggregates-custom)
### Examples
```
aggregates do
count :assigned_ticket_count, :reported_tickets do
filter [active: true]
end
end
```
## aggregates.count
```elixir
count name, relationship_path
```
Declares a named count aggregate on the resource
Supports `filter`, but not `sort` (because that wouldn't affect the count)
See the [aggregates guide](/documentation/topics/aggregates.md) for more.
### Examples
```
count :assigned_ticket_count, :assigned_tickets do
filter [active: true]
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-count-name" href="#aggregates-count-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to place the aggregate in
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-count-relationship_path" href="#aggregates-count-relationship_path">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_path
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">list(atom) | atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The relationship or relationship path to use for the aggregate
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-count-kind" href="#aggregates-count-kind">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
kind
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">:count | :first | :sum | :list | :avg | :max | :min | :exists | :custom | {:custom, module}</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The kind of the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-count-uniq?" href="#aggregates-count-uniq?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
uniq?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Wether or not to count unique values only
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-count-read_action" href="#aggregates-count-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action to use when building the aggregate. Defaults to the primary read action. Keep in mind this action must not have any required arguments.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-count-field" href="#aggregates-count-field">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
field
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to aggregate. Defaults to the first field in the primary key of the resource
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-count-filter" href="#aggregates-count-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
A filter to apply to the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-count-description" href="#aggregates-count-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-count-default" href="#aggregates-count-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A default value to use in cases where nil would be used. Count defaults to `0`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-count-private?" href="#aggregates-count-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-count-filterable?" href="#aggregates-count-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate should be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-count-authorize?" href="#aggregates-count-authorize?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
authorize?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Wether or not the aggregate query should authorize based on the target action, if the parent query is authorized. Requires filter checks on the target action.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Aggregate`
## aggregates.exists
```elixir
exists name, relationship_path
```
Declares a named `exists` aggregate on the resource
Supports `filter`, but not `sort` (because that wouldn't affect if something exists)
See the [aggregates guide](/documentation/topics/aggregates.md) for more.
### Examples
```
exists :has_ticket, :assigned_tickets
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-exists-name" href="#aggregates-exists-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to place the aggregate in
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-exists-relationship_path" href="#aggregates-exists-relationship_path">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_path
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">list(atom) | atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The relationship or relationship path to use for the aggregate
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-exists-kind" href="#aggregates-exists-kind">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
kind
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">:count | :first | :sum | :list | :avg | :max | :min | :exists | :custom | {:custom, module}</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The kind of the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-exists-read_action" href="#aggregates-exists-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action to use when building the aggregate. Defaults to the primary read action. Keep in mind this action must not have any required arguments.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-exists-filter" href="#aggregates-exists-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
A filter to apply to the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-exists-description" href="#aggregates-exists-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-exists-default" href="#aggregates-exists-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A default value to use in cases where nil would be used. Count defaults to `0`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-exists-private?" href="#aggregates-exists-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-exists-filterable?" href="#aggregates-exists-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate should be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-exists-authorize?" href="#aggregates-exists-authorize?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
authorize?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Wether or not the aggregate query should authorize based on the target action, if the parent query is authorized. Requires filter checks on the target action.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Aggregate`
## aggregates.first
```elixir
first name, relationship_path, field
```
Declares a named `first` aggregate on the resource
First aggregates return the first value of the related record
that matches. Supports both `filter` and `sort`.
See the [aggregates guide](/documentation/topics/aggregates.md) for more.
### Examples
```
first :first_assigned_ticket_subject, :assigned_tickets, :subject do
filter [active: true]
sort [:subject]
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-first-name" href="#aggregates-first-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to place the aggregate in
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-first-relationship_path" href="#aggregates-first-relationship_path">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_path
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">list(atom) | atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The relationship or relationship path to use for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-first-field" href="#aggregates-first-field">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
field
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to aggregate. Defaults to the first field in the primary key of the resource
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-first-kind" href="#aggregates-first-kind">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
kind
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">:count | :first | :sum | :list | :avg | :max | :min | :exists | :custom | {:custom, module}</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The kind of the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-first-read_action" href="#aggregates-first-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action to use when building the aggregate. Defaults to the primary read action. Keep in mind this action must not have any required arguments.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-first-filter" href="#aggregates-first-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
A filter to apply to the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-first-sort" href="#aggregates-first-sort">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sort
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A sort to be applied to the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-first-description" href="#aggregates-first-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-first-default" href="#aggregates-first-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A default value to use in cases where nil would be used. Count defaults to `0`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-first-private?" href="#aggregates-first-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-first-filterable?" href="#aggregates-first-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate should be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-first-authorize?" href="#aggregates-first-authorize?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
authorize?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Wether or not the aggregate query should authorize based on the target action, if the parent query is authorized. Requires filter checks on the target action.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Aggregate`
## aggregates.sum
```elixir
sum name, relationship_path, field
```
Declares a named `sum` aggregate on the resource
Supports `filter`, but not `sort` (because that wouldn't affect the sum)
See the [aggregates guide](/documentation/topics/aggregates.md) for more.
### Examples
```
sum :assigned_ticket_price_sum, :assigned_tickets, :price do
filter [active: true]
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-sum-name" href="#aggregates-sum-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to place the aggregate in
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-sum-relationship_path" href="#aggregates-sum-relationship_path">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_path
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">list(atom) | atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The relationship or relationship path to use for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-sum-field" href="#aggregates-sum-field">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
field
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to aggregate. Defaults to the first field in the primary key of the resource
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-sum-kind" href="#aggregates-sum-kind">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
kind
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">:count | :first | :sum | :list | :avg | :max | :min | :exists | :custom | {:custom, module}</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The kind of the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-sum-read_action" href="#aggregates-sum-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action to use when building the aggregate. Defaults to the primary read action. Keep in mind this action must not have any required arguments.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-sum-filter" href="#aggregates-sum-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
A filter to apply to the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-sum-description" href="#aggregates-sum-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-sum-default" href="#aggregates-sum-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A default value to use in cases where nil would be used. Count defaults to `0`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-sum-private?" href="#aggregates-sum-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-sum-filterable?" href="#aggregates-sum-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate should be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-sum-authorize?" href="#aggregates-sum-authorize?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
authorize?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Wether or not the aggregate query should authorize based on the target action, if the parent query is authorized. Requires filter checks on the target action.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Aggregate`
## aggregates.list
```elixir
list name, relationship_path, field
```
Declares a named `list` aggregate on the resource.
A list aggregate selects the list of all values for the given field
and relationship combination.
See the [aggregates guide](/documentation/topics/aggregates.md) for more.
### Examples
```
list :assigned_ticket_prices, :assigned_tickets, :price do
filter [active: true]
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-list-name" href="#aggregates-list-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to place the aggregate in
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-list-relationship_path" href="#aggregates-list-relationship_path">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_path
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">list(atom) | atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The relationship or relationship path to use for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-list-field" href="#aggregates-list-field">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
field
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to aggregate. Defaults to the first field in the primary key of the resource
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-list-kind" href="#aggregates-list-kind">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
kind
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">:count | :first | :sum | :list | :avg | :max | :min | :exists | :custom | {:custom, module}</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The kind of the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-list-uniq?" href="#aggregates-list-uniq?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
uniq?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Wether or not to count unique values only
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-list-read_action" href="#aggregates-list-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action to use when building the aggregate. Defaults to the primary read action. Keep in mind this action must not have any required arguments.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-list-filter" href="#aggregates-list-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
A filter to apply to the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-list-sort" href="#aggregates-list-sort">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sort
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A sort to be applied to the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-list-description" href="#aggregates-list-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-list-default" href="#aggregates-list-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A default value to use in cases where nil would be used. Count defaults to `0`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-list-private?" href="#aggregates-list-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-list-filterable?" href="#aggregates-list-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate should be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-list-authorize?" href="#aggregates-list-authorize?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
authorize?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Wether or not the aggregate query should authorize based on the target action, if the parent query is authorized. Requires filter checks on the target action.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Aggregate`
## aggregates.max
```elixir
max name, relationship_path, field
```
Declares a named `max` aggregate on the resource
Supports `filter`, but not `sort` (because that wouldn't affect the max)
See the [aggregates guide](/documentation/topics/aggregates.md) for more.
### Examples
```
max :first_assigned_ticket_subject, :assigned_tickets, :severity do
filter [active: true]
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-max-name" href="#aggregates-max-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to place the aggregate in
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-max-relationship_path" href="#aggregates-max-relationship_path">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_path
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">list(atom) | atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The relationship or relationship path to use for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-max-field" href="#aggregates-max-field">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
field
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to aggregate. Defaults to the first field in the primary key of the resource
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-max-kind" href="#aggregates-max-kind">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
kind
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">:count | :first | :sum | :list | :avg | :max | :min | :exists | :custom | {:custom, module}</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The kind of the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-max-read_action" href="#aggregates-max-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action to use when building the aggregate. Defaults to the primary read action. Keep in mind this action must not have any required arguments.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-max-filter" href="#aggregates-max-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
A filter to apply to the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-max-description" href="#aggregates-max-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-max-default" href="#aggregates-max-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A default value to use in cases where nil would be used. Count defaults to `0`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-max-private?" href="#aggregates-max-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-max-filterable?" href="#aggregates-max-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate should be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-max-authorize?" href="#aggregates-max-authorize?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
authorize?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Wether or not the aggregate query should authorize based on the target action, if the parent query is authorized. Requires filter checks on the target action.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Aggregate`
## aggregates.min
```elixir
min name, relationship_path, field
```
Declares a named `min` aggregate on the resource
Supports `filter`, but not `sort` (because that wouldn't affect the min)
See the [aggregates guide](/documentation/topics/aggregates.md) for more.
### Examples
```
min :first_assigned_ticket_subject, :assigned_tickets, :severity do
filter [active: true]
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-min-name" href="#aggregates-min-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to place the aggregate in
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-min-relationship_path" href="#aggregates-min-relationship_path">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_path
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">list(atom) | atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The relationship or relationship path to use for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-min-field" href="#aggregates-min-field">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
field
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to aggregate. Defaults to the first field in the primary key of the resource
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-min-kind" href="#aggregates-min-kind">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
kind
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">:count | :first | :sum | :list | :avg | :max | :min | :exists | :custom | {:custom, module}</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The kind of the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-min-read_action" href="#aggregates-min-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action to use when building the aggregate. Defaults to the primary read action. Keep in mind this action must not have any required arguments.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-min-filter" href="#aggregates-min-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
A filter to apply to the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-min-description" href="#aggregates-min-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-min-default" href="#aggregates-min-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A default value to use in cases where nil would be used. Count defaults to `0`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-min-private?" href="#aggregates-min-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-min-filterable?" href="#aggregates-min-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate should be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-min-authorize?" href="#aggregates-min-authorize?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
authorize?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Wether or not the aggregate query should authorize based on the target action, if the parent query is authorized. Requires filter checks on the target action.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Aggregate`
## aggregates.avg
```elixir
avg name, relationship_path, field
```
Declares a named `avg` aggregate on the resource
Supports `filter`, but not `sort` (because that wouldn't affect the avg)
See the [aggregates guide](/documentation/topics/aggregates.md) for more.
### Examples
```
avg :assigned_ticket_price_sum, :assigned_tickets, :price do
filter [active: true]
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-avg-name" href="#aggregates-avg-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to place the aggregate in
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-avg-relationship_path" href="#aggregates-avg-relationship_path">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_path
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">list(atom) | atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The relationship or relationship path to use for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-avg-field" href="#aggregates-avg-field">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
field
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to aggregate. Defaults to the first field in the primary key of the resource
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-avg-kind" href="#aggregates-avg-kind">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
kind
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">:count | :first | :sum | :list | :avg | :max | :min | :exists | :custom | {:custom, module}</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The kind of the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-avg-read_action" href="#aggregates-avg-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action to use when building the aggregate. Defaults to the primary read action. Keep in mind this action must not have any required arguments.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-avg-filter" href="#aggregates-avg-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
A filter to apply to the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-avg-description" href="#aggregates-avg-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-avg-default" href="#aggregates-avg-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A default value to use in cases where nil would be used. Count defaults to `0`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-avg-private?" href="#aggregates-avg-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-avg-filterable?" href="#aggregates-avg-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate should be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-avg-authorize?" href="#aggregates-avg-authorize?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
authorize?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Wether or not the aggregate query should authorize based on the target action, if the parent query is authorized. Requires filter checks on the target action.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Aggregate`
## aggregates.custom
```elixir
custom name, relationship_path, type
```
Declares a named `custom` aggregate on the resource
Supports `filter` and `sort`.
Custom aggregates provide an `implementation` which must implement data layer specific callbacks.
See the relevant data layer documentation and the [aggregates guide](/documentation/topics/aggregates.md) for more.
### Examples
```
custom :author_names, :authors, :string do
implementation {StringAgg, delimiter: ","}
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-name" href="#aggregates-custom-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to place the aggregate in
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-relationship_path" href="#aggregates-custom-relationship_path">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
relationship_path
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">list(atom) | atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The relationship or relationship path to use for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-type" href="#aggregates-custom-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the value returned by the aggregate
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-implementation" href="#aggregates-custom-implementation">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
implementation
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The module that implements the relevant data layer callbacks
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-kind" href="#aggregates-custom-kind">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
kind
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">:count | :first | :sum | :list | :avg | :max | :min | :exists | :custom | {:custom, module}</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The kind of the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-read_action" href="#aggregates-custom-read_action">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
read_action
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The read action to use when building the aggregate. Defaults to the primary read action. Keep in mind this action must not have any required arguments.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-field" href="#aggregates-custom-field">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
field
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field to aggregate. Defaults to the first field in the primary key of the resource
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-filter" href="#aggregates-custom-filter">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filter
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
A filter to apply to the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-sort" href="#aggregates-custom-sort">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
sort
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A sort to be applied to the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-description" href="#aggregates-custom-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the aggregate
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-default" href="#aggregates-custom-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A default value to use in cases where nil would be used. Count defaults to `0`.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-private?" href="#aggregates-custom-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-filterable?" href="#aggregates-custom-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the aggregate should be usable in filters.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="aggregates-custom-authorize?" href="#aggregates-custom-authorize?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
authorize?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Wether or not the aggregate query should authorize based on the target action, if the parent query is authorized. Requires filter checks on the target action.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Aggregate`
## calculations
Declare named calculations on the resource.
These are calculations that can be loaded only by name using `Ash.Query.load/2`.
They are also available as top level fields on the resource.
See the [calculations guide](/documentation/topics/calculations.md) for more.
### Nested DSLs
* [calculate](#calculations-calculate)
* argument
### Examples
```
calculations do
calculate :full_name, :string, MyApp.MyResource.FullName
end
```
## calculations.calculate
```elixir
calculate name, type, calculation \ nil
```
Declares a named calculation on the resource.
Takes a module that must adopt the `Ash.Calculation` behaviour. See that module
for more information.
To ensure that the necessary fields are selected:
1.) Specifying the `select` option on a calculation in the resource.
2.) Define a `select/2` callback in the calculation module
3.) Set `always_select?` on the attribute in question
See the [calculations guide](/documentation/topics/calculations.md) for more.
### Nested DSLs
* [argument](#calculations-calculate-argument)
### Examples
`Ash.Calculation` implementation example:
```
calculate :full_name, :string, {MyApp.FullName, keys: [:first_name, :last_name]}, select: [:first_name, :last_name]
```
`expr/1` example:
```
calculate :full_name, :string, expr(first_name <> " " <> last_name)
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-name" href="#calculations-calculate-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The field name to use for the calculation value
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-type" href="#calculations-calculate-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the calculation. See `Ash.Type` for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-calculation" href="#calculations-calculate-calculation">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
calculation
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">(any, any -> any) | module | `any`</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The `module`, `{module, opts}` or `expr(...)` to use for the calculation. Also accepts a function that takes *a single record* and produces the result.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-constraints" href="#calculations-calculate-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Constraints to provide to the type. See `Ash.Type` for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-description" href="#calculations-calculate-description">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
description
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">String.t</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
An optional description for the calculation
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-private?" href="#calculations-calculate-private?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
private?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the calculation will appear in any interfaces created off of this resource, e.g AshJsonApi and AshGraphql See the [security guide](/documentation/topics/security.md) for more.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-select" href="#calculations-calculate-select">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
select
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">list(atom)</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
A list of fields to ensure selected if the calculation is used.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-load" href="#calculations-calculate-load">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
load
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">`any`</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
A load statement to be applied if the calculation is used.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-allow_nil?" href="#calculations-calculate-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the calculation can return nil.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-filterable?" href="#calculations-calculate-filterable?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
filterable?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean | :simple_equality</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the calculation should be usable in filters.
</td>
</tr>
</tbody>
</table>
## calculations.calculate.argument
```elixir
argument name, type
```
An argument to be passed into the calculation's arguments map
See the [calculations guide](/documentation/topics/calculations.md) for more.
### Examples
```
argument :params, :map do
default %{}
end
```
```
argument :retries, :integer do
allow_nil? false
end
```
### Arguments
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-argument-name" href="#calculations-calculate-argument-name">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
name
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The name of the argument
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-argument-type" href="#calculations-calculate-argument-type">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
type
</span>
</a>
<sup style="color: red">*</sup>
</td>
<td style="text-align: left">
<code class="inline">module</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
The type of the argument. See `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-argument-default" href="#calculations-calculate-argument-default">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
default
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">(-> any) | mfa | any()</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
A default value to use for the argument if not provided
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-argument-allow_nil?" href="#calculations-calculate-argument-allow_nil?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_nil?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">true</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the argument value may be nil (or may be not provided)
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-argument-allow_expr?" href="#calculations-calculate-argument-allow_expr?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
allow_expr?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Allow passing expressions as argument values. Expressions cannot be type validated.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="calculations-calculate-argument-constraints" href="#calculations-calculate-argument-constraints">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
constraints
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">Keyword.t</code>
</td>
<td style="text-align: left">
<code class="inline">[]</code>
</td>
<td style="text-align: left" colspan=2>
Constraints to provide to the type when casting the value. See the type's documentation and `Ash.Type` for more.
</td>
</tr>
</tbody>
</table>
### Introspection
Target: `Ash.Resource.Calculation.Argument`
### Introspection
Target: `Ash.Resource.Calculation`
## multitenancy
Options for configuring the multitenancy behavior of a resource.
To specify a tenant, use `Ash.Query.set_tenant/2` or
`Ash.Changeset.set_tenant/2` before passing it to an operation.
See the [multitenancy guide](/documentation/topics/multitenancy.md)
### Examples
```
multitenancy do
strategy :attribute
attribute :organization_id
global? true
end
```
### Options
<table>
<thead>
<tr>
<th>Name</th>
<th>Type</th>
<th>Default</th>
<th colspan=2>Docs</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a id="multitenancy-strategy" href="#multitenancy-strategy">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
strategy
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">:context | :attribute</code>
</td>
<td style="text-align: left">
<code class="inline">:context</code>
</td>
<td style="text-align: left" colspan=2>
Determine if multitenancy is performed with attribute filters or using data layer features.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="multitenancy-attribute" href="#multitenancy-attribute">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
attribute
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">atom</code>
</td>
<td style="text-align: left">
</td>
<td style="text-align: left" colspan=2>
If using the `attribute` strategy, the attribute to use, e.g `org_id`
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="multitenancy-global?" href="#multitenancy-global?">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
global?
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">boolean</code>
</td>
<td style="text-align: left">
<code class="inline">false</code>
</td>
<td style="text-align: left" colspan=2>
Whether or not the data also exists outside of each tenant.
</td>
</tr>
<tr>
<td style="text-align: left">
<a id="multitenancy-parse_attribute" href="#multitenancy-parse_attribute">
<span style="font-family: Inconsolata, Menlo, Courier, monospace;">
parse_attribute
</span>
</a>
</td>
<td style="text-align: left">
<code class="inline">mfa</code>
</td>
<td style="text-align: left">
<code class="inline">{Ash.Resource.Dsl, :identity, []}</code>
</td>
<td style="text-align: left" colspan=2>
An mfa ({module, function, args}) pointing to a function that takes a tenant and returns the attribute value
</td>
</tr>
</tbody>
</table>
