defprotocol Flop.Schema do
@moduledoc """
This protocol allows you to set query options in your Ecto schemas.
## Usage
Derive `Flop.Schema` in your Ecto schema and set the filterable and sortable
fields.
defmodule Flop.Pet do
use Ecto.Schema
@derive {
Flop.Schema,
filterable: [:name, :species],
sortable: [:name, :age]
}
schema "pets" do
field :name, :string
field :age, :integer
field :species, :string
end
end
After that, you can pass the module as the `:for` option to `Flop.validate/2`.
iex> Flop.validate(%Flop{order_by: [:name]}, for: Flop.Pet)
{:ok,
%Flop{
filters: [],
limit: 50,
offset: nil,
order_by: [:name],
order_directions: nil,
page: nil,
page_size: nil
}}
iex> {:error, %Flop.Meta{} = meta} = Flop.validate(
...> %Flop{order_by: [:species]}, for: Flop.Pet
...> )
iex> meta.params
%{"order_by" => [:species], "filters" => []}
iex> meta.errors
[
order_by: [
{"has an invalid entry",
[validation: :subset, enum: [:name, :age, :owner_name, :owner_age]]}
]
]
## Default and maximum limits
To define a default or maximum limit, you can set the `default_limit` and
`max_limit` option when deriving `Flop.Schema`. The maximum limit will be
validated and the default limit applied by `Flop.validate/1`.
@derive {
Flop.Schema,
filterable: [:name, :species],
sortable: [:name, :age],
max_limit: 100,
default_limit: 50
}
## Default sort order
To define a default sort order, you can set the `default_order_by` and
`default_order_directions` options when deriving `Flop.Schema`. The default
values are applied by `Flop.validate/1`. If no order directions are set,
`:asc` is assumed for all fields.
@derive {
Flop.Schema,
filterable: [:name, :species],
sortable: [:name, :age],
default_order: %{
order_by: [:name, :age],
order_directions: [:asc, :desc]
}
}
## Restricting pagination types
By default, `page`/`page_size`, `offset`/`limit` and cursor-based pagination
(`first`/`after` and `last`/`before`) are enabled. If you want to restrict the
pagination type for a schema, you can do that by setting the
`pagination_types` option.
@derive {
Flop.Schema,
filterable: [:name, :species],
sortable: [:name, :age],
pagination_types: [:first, :last]
}
See also `t:Flop.option/0` and `t:Flop.pagination_type/0`. Setting the value
to `nil` allows all pagination types.
## Alias fields
To sort by calculated values, you can use `Ecto.Query.API.selected_as/2` in
your query, define an alias field in your schema, and add the alias field to
the list of sortable fields.
Schema:
@derive {
Flop.Schema,
filterable: [],
sortable: [:pet_count],
alias_fields: [:pet_count]
}
Query:
Owner
|> join(:left, [o], p in assoc(o, :pets), as: :pets)
|> group_by([o], o.id)
|> select(
[o, pets: p],
{o.id, p.id |> count() |> selected_as(:pet_count)}
)
|> Flop.validate_and_run(params, for: Owner)
Note that it is not possible to use field aliases in `WHERE` clauses, which
means you cannot add alias fields to the list of filterable fields, and you
cannot sort by an alias field if you are using cursor-based pagination.
## Compound fields
Sometimes you might need to apply a search term to multiple fields at once,
e.g. you might want to search in both the family name and given name field.
You can do that with Flop by defining a compound field.
@derive {
Flop.Schema,
filterable: [:full_name],
sortable: [:full_name],
compound_fields: [full_name: [:family_name, :given_name]]
}
This allows you to use the field name `:full_name` as any other field in the
filter and order parameters.
### Filtering
params = %{
filters: [%{
field: :full_name,
op: :==,
value: "margo"
}]
}
This would translate to:
WHERE family_name='margo' OR given_name ='margo'
Partial matches of the search term can be achieved with one of
the ilike operators.
params = %{
filters: [%{
field: :full_name,
op: :ilike_and,
value: ["margo", "martindale"]
}]
}
or
params = %{
filters: [%{
field: :full_name,
op: :ilike_and,
value: "margo martindale""
}]
}
This would translate to:
WHERE (family_name ilike '%margo%' OR given_name ='%margo%')
AND (family_name ilike '%martindale%' OR given_name ='%martindale%')
### Filter operator rules
- `:=~`, `:like`, `:not_like`, `:like_and`, `:like_or`, `:ilike`, `:not_ilike`, `:ilike_and`,
`:ilike_or` - If a string value is passed, it will be split at whitespace
characters and each segment will be checked for. If a list of strings is
passed, the individual strings are not split. The filter matches for a value
if it matches for any of the fields.
- `:empty` - Matches if all fields of the compound field are `nil`.
- `:not_empty` - Matches if any field of the compound field is not `nil`.
- `:==`, `:!=`, `:<=`, `:<`, `:>=`, `:>`, `:in`, `:not_in`, `:contains`
`:not_contains`
- The filter value is normalized by splitting the string at whitespaces and
joining it with a space. The values of all fields of the compound field are
split by whitespace character and joined with a space, and the resulting
values are joined with a space again. **This will be added in a future
version. These filter operators are ignored for compound fields at the
moment.**
### Sorting
params = %{
order_by: [:full_name],
order_directions: [:desc]
}
This would translate to:
ORDER BY family_name DESC, given_name DESC
Note that compound fields cannot be used as pagination cursors.
## Join fields
If you need to filter or order across tables, you can define join fields.
As an example, let's define these schemas:
schema "owners" do
field :name, :string
field :email, :string
has_many :pets, Pet
end
schema "pets" do
field :name, :string
field :species, :string
belongs_to :owner, Owner
end
And now we want to find all owners that have pets of the species
`"E. africanus"`. To do this, first we need to define a join field on the
`Owner` schema.
@derive {
Flop.Schema,
filterable: [:pet_species],
sortable: [:pet_species],
join_fields: [pet_species: [binding: :pets, field: :species]]
}
In this case, `:pet_species` would be the alias of the field that you can
refer to in the filter and order parameters. The `:binding` option refers to
the named binding you set with the `:as` option in the join statement of your
query. `:field` is the field name on that binding.
You can also set the `ecto_type` option, which allows Flop to determine which
filter operators can be used on the field during the validation. This is also
important if the field is a map or array field, so that Flop can check for
empty arrays and empty maps when a `empty` or `not_empty` filter is used.
@derive {
Flop.Schema,
filterable: [:pet_species],
sortable: [:pet_species],
join_fields: [
pet_species: [
binding: :pets,
field: :species,
ecto_type: :string
]
]
}
There is also a short syntax which you can use if you only want to specify
the binding and the field:
@derive {
Flop.Schema,
filterable: [:pet_species],
sortable: [:pet_species],
join_fields: [pet_species: {:pets, :species}]
}
In order to retrieve the pagination cursor value for a join field, Flop needs
to know how to get the field value from the struct that is returned from the
database. `Flop.Schema.get_field/2` is used for that. By default, Flop assumes
that the binding name matches the name of the field for the association in
your Ecto schema (the one you set with `has_one`, `has_many` or `belongs_to`).
In the example above, Flop would try to access the field in the struct under
the path `[:pets, :species]`.
If you have joins across multiple tables, or if you can't give the binding
the same name as the association field, you can specify the path explicitly.
@derive {
Flop.Schema,
filterable: [:pet_species],
sortable: [:pet_species],
join_fields: [
pet_species: [
binding: :pets,
field: :species,
path: [:pets, :species]
]
}
After setting up the join fields, you can write a query like this:
params = %{
filters: [%{field: :pet_species, op: :==, value: "E. africanus"}]
}
Owner
|> join(:left, [o], p in assoc(o, :pets), as: :pets)
|> preload([pets: p], [pets: p])
|> Flop.validate_and_run!(params, for: Owner)
If your query returns data in a different format, you don't need to set the
`:path` option. Instead, you can pass a custom cursor value function in the
options. See `Flop.Cursor.get_cursors/2` and `t:Flop.option/0`.
Note that Flop doesn't create the join clauses for you. The named bindings
already have to be present in the query you pass to the Flop functions. You
can use `Flop.with_named_bindings/4` or `Flop.named_bindings/3` to get the
build the join clauses needed for a query dynamically and avoid adding
unnecessary joins.
## Filtering by calculated values with subqueries
You can join on a subquery with a named binding and add a join field as
described above.
Schema:
@derive {
Flop.Schema,
filterable: [:pet_count],
sortable: [:pet_count],
join_fields: [pet_count: [{:pet_count, :count}]}
Query:
params = %{filters: [%{field: :pet_count, op: :>, value: 2}]}
pet_count_query =
Pet
|> where([p], parent_as(:owner).id == p.owner_id)
|> select([p], %{count: count(p)})
q =
(o in Owner)
|> from(as: :owner)
|> join(:inner_lateral, [owner: o], p in subquery(pet_count_query),
as: :pet_count
)
|> Flop.validate_and_run(params, for: Owner)
## Custom fields
If you need more control over the queries produced by the filters, you can
define custom fields that reference a function which implements the filter
logic. Custom field filters are referenced by
`{mod :: module, function :: atom, opts :: keyword}`. The function will
receive the Ecto query, the flop filter, and the option keyword list.
If you need to pass in options at runtime (e.g. the timezone of the request,
the user ID of the current user etc.), you can do so by passing in the
`extra_opts` option to the flop functions. Currently, custom fields only
support filtering and can not be used for sorting.
Schema:
@derive {
Flop.Schema,
filterable: [:inserted_at_date],
custom_fields: [
inserted_at_date: [
filter: {CustomFilters, :date_filter, [source: :inserted_at]},
ecto_type: :date
]
]
}
Filter module:
defmodule CustomFilters do
def date_filter(query, %Flop.Filter{value: value, op: op}, opts) do
source = Keyword.fetch!(opts, :source)
timezone = Keyword.fetch!(opts, :timezone)
expr = dynamic([r], fragment("((? AT TIME ZONE 'utc') AT TIME ZONE ?)::date", field(r, source), ^timezone)
case Ecto.Type.cast(:date, value) do
{:ok, date} ->
conditions =
case op do
:>= -> dynamic([r], ^expr >= ^date)
:<= -> dynamic([r], ^expr <= ^date)
end
where(query, ^conditions)
:error ->
query
end
end
end
Query:
Flop.validate_and_run(Flop.Pet, params, for: Flop.Pet, extra_opts: [timezone: timezone])
"""
@fallback_to_any true
@doc """
Returns the field type in a schema.
- `{:normal, atom}` - An ordinary field on the schema. The second tuple
element is the field name.
- `{:compound, [atom]}` - A combination of fields defined with the
`compound_fields` option. The list of atoms refers to the list of fields
that are included.
- `{:join, map}` - A field from a named binding as defined with the
`join_fields` option. The map has keys for the `:binding`, `:field` and
`:path`.
- `{:custom, keyword}` - A filter field that uses a custom filter function.
## Examples
iex> field_type(%Flop.Pet{}, :age)
{:normal, :age}
iex> field_type(%Flop.Pet{}, :full_name)
{:compound, [:family_name, :given_name]}
iex> field_type(%Flop.Pet{}, :owner_name)
{
:join,
%{
binding: :owner,
field: :name,
path: [:owner, :name],
ecto_type: :string
}
}
iex> field_type(%Flop.Pet{}, :reverse_name)
{
:custom,
%{
filter: {Flop.Pet, :reverse_name_filter, []},
ecto_type: :string
}
}
"""
@doc since: "0.11.0"
@spec field_type(any, atom) ::
{:normal, atom}
| {:compound, [atom]}
| {:join, map}
| {:alias, atom}
| {:custom, map}
def field_type(data, field)
@doc """
Returns the filterable fields of a schema.
iex> Flop.Schema.filterable(%Flop.Pet{})
[
:age,
:full_name,
:name,
:owner_age,
:owner_name,
:owner_tags,
:pet_and_owner_name,
:species,
:tags,
:custom,
:reverse_name
]
"""
@spec filterable(any) :: [atom]
def filterable(data)
@doc false
@spec apply_order_by(any, Ecto.Query.t(), tuple | keyword) :: Ecto.Query.t()
def apply_order_by(data, q, expr)
@doc false
@spec cursor_dynamic(any, keyword, map) :: any
def cursor_dynamic(data, order, cursor_map)
@doc """
Gets the field value from a struct.
Resolves join fields and compound fields according to the config.
# join_fields: [owner_name: {:owner, :name}]
iex> pet = %Flop.Pet{name: "George", owner: %Flop.Owner{name: "Carl"}}
iex> Flop.Schema.get_field(pet, :name)
"George"
iex> Flop.Schema.get_field(pet, :owner_name)
"Carl"
# compound_fields: [full_name: [:family_name, :given_name]]
iex> pet = %Flop.Pet{given_name: "George", family_name: "Gooney"}
iex> Flop.Schema.get_field(pet, :full_name)
"Gooney George"
For join fields, this function relies on the binding name in the schema config
matching the field name for the association in the struct.
"""
@doc since: "0.13.0"
@spec get_field(any, atom) :: any
def get_field(data, field)
@doc """
Returns the allowed pagination types of a schema.
iex> Flop.Schema.pagination_types(%Flop.Fruit{})
[:first, :last, :offset]
"""
@doc since: "0.9.0"
@spec pagination_types(any) :: [Flop.pagination_type()] | nil
def pagination_types(data)
@doc """
Returns the sortable fields of a schema.
iex> Flop.Schema.sortable(%Flop.Pet{})
[:name, :age, :owner_name, :owner_age]
"""
@spec sortable(any) :: [atom]
def sortable(data)
@doc """
Returns the default limit of a schema.
iex> Flop.Schema.default_limit(%Flop.Fruit{})
60
"""
@doc since: "0.3.0"
@spec default_limit(any) :: pos_integer | nil
def default_limit(data)
@doc """
Returns the default order of a schema.
iex> Flop.Schema.default_order(%Flop.Fruit{})
%{order_by: [:name], order_directions: [:asc]}
"""
@doc since: "0.7.0"
@spec default_order(any) ::
%{
order_by: [atom] | nil,
order_directions: [Flop.order_direction()] | nil
}
| nil
def default_order(data)
@doc """
Returns the maximum limit of a schema.
iex> Flop.Schema.max_limit(%Flop.Pet{})
1000
"""
@doc since: "0.2.0"
@spec max_limit(any) :: pos_integer | nil
def max_limit(data)
end
defimpl Flop.Schema, for: Any do
@instructions """
Flop.Schema protocol must always be explicitly implemented.
To do this, you have to derive Flop.Schema in your Ecto schema module. You
have to set both the filterable and the sortable option.
@derive {
Flop.Schema,
filterable: [:name, :species],
sortable: [:name, :age, :species]
}
schema "pets" do
field :name, :string
field :age, :integer
field :species, :string
end
"""
# credo:disable-for-next-line
defmacro __deriving__(module, struct, options) do
validate_options!(options, struct)
filterable_fields = Keyword.get(options, :filterable)
sortable_fields = Keyword.get(options, :sortable)
default_limit = Keyword.get(options, :default_limit)
max_limit = Keyword.get(options, :max_limit)
pagination_types = Keyword.get(options, :pagination_types)
default_order = Keyword.get(options, :default_order)
compound_fields = Keyword.get(options, :compound_fields, [])
alias_fields = Keyword.get(options, :alias_fields, [])
custom_fields =
options
|> Keyword.get(:custom_fields, [])
|> Enum.map(&normalize_custom_opts/1)
join_fields =
options
|> Keyword.get(:join_fields, [])
|> Enum.map(&normalize_join_opts/1)
field_type_func =
build_field_type_func(
compound_fields,
join_fields,
alias_fields,
custom_fields
)
order_by_func =
build_order_by_func(compound_fields, join_fields, alias_fields)
get_field_func = build_get_field_func(compound_fields, join_fields)
cursor_dynamic_func_compound =
build_cursor_dynamic_func_compound(compound_fields)
cursor_dynamic_func_join = build_cursor_dynamic_func_join(join_fields)
cursor_dynamic_func_alias = build_cursor_dynamic_func_alias(alias_fields)
cursor_dynamic_func_normal = build_cursor_dynamic_func_normal()
quote do
defimpl Flop.Schema, for: unquote(module) do
import Ecto.Query
require Logger
def default_limit(_) do
unquote(default_limit)
end
def default_order(_) do
unquote(Macro.escape(default_order))
end
unquote(field_type_func)
unquote(order_by_func)
unquote(get_field_func)
def filterable(_) do
unquote(filterable_fields)
end
def max_limit(_) do
unquote(max_limit)
end
def pagination_types(_) do
unquote(pagination_types)
end
def sortable(_) do
unquote(sortable_fields)
end
def cursor_dynamic(_, [], _), do: true
unquote(cursor_dynamic_func_compound)
unquote(cursor_dynamic_func_join)
unquote(cursor_dynamic_func_alias)
unquote(cursor_dynamic_func_normal)
end
end
end
defp validate_options!(opts, struct) do
if is_nil(opts[:filterable]) || is_nil(opts[:sortable]),
do: raise(ArgumentError, @instructions)
compound_fields = get_compound_fields(opts)
join_fields = get_join_fields(opts)
schema_fields = get_schema_fields(struct)
alias_fields = Keyword.get(opts, :alias_fields, [])
custom_fields = get_custom_fields(opts)
all_fields =
compound_fields ++
join_fields ++ schema_fields ++ alias_fields ++ custom_fields
validate_no_duplicate_fields!(
compound_fields ++ join_fields ++ alias_fields ++ custom_fields
)
validate_limit!(opts[:default_limit], "default")
validate_limit!(opts[:max_limit], "max")
validate_pagination_types!(opts[:pagination_types])
check_legacy_default_order(opts)
validate_no_unknown_options!(opts)
validate_no_unknown_field!(opts[:filterable], all_fields, "filterable")
validate_no_unknown_field!(opts[:sortable], all_fields, "sortable")
validate_default_order!(opts[:default_order], opts[:sortable])
validate_compound_fields!(opts[:compound_fields], all_fields)
validate_alias_fields!(alias_fields, opts[:filterable])
validate_custom_fields!(opts[:custom_fields], opts[:sortable])
end
defp get_compound_fields(opts) do
opts |> Keyword.get(:compound_fields, []) |> Keyword.keys()
end
defp get_join_fields(opts) do
opts |> Keyword.get(:join_fields, []) |> Keyword.keys()
end
defp get_custom_fields(opts) do
opts |> Keyword.get(:custom_fields, []) |> Keyword.keys()
end
defp get_schema_fields(struct) do
# reflection functions are not available during compilation
struct
|> Map.from_struct()
|> Enum.reject(fn
{_, %Ecto.Association.NotLoaded{}} -> true
{:__meta__, _} -> true
_ -> false
end)
|> Enum.map(fn {field, _} -> field end)
end
defp validate_limit!(nil, _), do: :ok
defp validate_limit!(i, _) when is_integer(i) and i > 0, do: :ok
defp validate_limit!(i, type) do
raise ArgumentError, """
invalid #{type} limit
expected non-negative integer, got: #{inspect(i)}
"""
end
defp validate_pagination_types!(nil), do: :ok
defp validate_pagination_types!(types) when is_list(types) do
valid_types = [:offset, :page, :first, :last]
unknown = Enum.uniq(types) -- valid_types
if unknown != [] do
raise ArgumentError,
"""
invalid pagination type
expected one of #{inspect(valid_types)}, got: #{inspect(unknown)}
"""
end
end
defp validate_pagination_types!(types) do
raise ArgumentError, """
invalid pagination type
expected list of atoms, got: #{inspect(types)}
"""
end
defp validate_no_unknown_options!(opts) do
known_keys = [
:alias_fields,
:compound_fields,
:custom_fields,
:default_limit,
:default_order,
:filterable,
:join_fields,
:max_limit,
:pagination_types,
:sortable
]
unknown_keys = Keyword.keys(opts) -- known_keys
if unknown_keys != [] do
raise ArgumentError, "unknown option(s): #{inspect(unknown_keys)}"
end
end
defp validate_no_unknown_field!(fields, known_fields, type) do
unknown_fields = fields -- known_fields
if unknown_fields != [] do
raise ArgumentError,
"unknown #{type} field(s): #{inspect(unknown_fields)}"
end
end
defp validate_default_order!(nil, _), do: :ok
defp validate_default_order!(%{} = map, sortable_fields) do
if Map.keys(map) -- [:order_by, :order_directions] != [] do
raise ArgumentError, default_order_error(map)
end
order_by = Map.get(map, :order_by, [])
order_directions = Map.get(map, :order_directions, [])
if !is_list(order_by) || !is_list(order_directions) do
raise ArgumentError, default_order_error(map)
end
unsortable_fields = Enum.uniq(order_by) -- sortable_fields
if unsortable_fields != [] do
raise ArgumentError, """
invalid default order
Default order fields must be sortable, but these fields are not:
#{inspect(unsortable_fields)}
"""
end
valid_directions = [
:asc,
:asc_nulls_first,
:asc_nulls_last,
:desc,
:desc_nulls_first,
:desc_nulls_last
]
invalid_directions = Enum.uniq(order_directions) -- valid_directions
if invalid_directions != [] do
raise ArgumentError, """
invalid default order
Invalid order direction(s):
#{inspect(invalid_directions)}
"""
end
end
defp validate_default_order!(value, _) do
raise ArgumentError, default_order_error(value)
end
defp default_order_error(value) do
"""
invalid default order
expected a map like this:
%{order_by: [:some_field], order_directions: [:asc]}
got:
#{inspect(value)}
"""
end
defp validate_compound_fields!(nil, _), do: :ok
defp validate_compound_fields!(compound_fields, known_fields)
when is_list(compound_fields) do
Enum.each(compound_fields, fn {field, fields} ->
unknown_fields = fields -- known_fields
if unknown_fields != [] do
raise ArgumentError, """
compound field references unknown field(s)
Compound fields must reference existing fields, but #{inspect(field)}
references:
#{inspect(unknown_fields)}
"""
end
end)
end
defp validate_alias_fields!(alias_fields, filterable)
when is_list(alias_fields) do
illegal_fields = Enum.filter(alias_fields, &(&1 in filterable))
if illegal_fields != [] do
raise ArgumentError, """
cannot filter by alias fields
Alias fields are not allowed to be filterable. These alias fields were
configured as filterable:
#{inspect(illegal_fields)}
Use custom fields if you want to implement custom filtering.
"""
end
end
defp validate_custom_fields!(nil, _), do: :ok
defp validate_custom_fields!(custom_fields, sortable)
when is_list(custom_fields) do
illegal_fields =
Enum.filter(custom_fields, fn {field, _} -> field in sortable end)
if illegal_fields != [] do
raise ArgumentError, """
cannot sort by custom fields
Custom fields are not allowed to be sortable. These custom fields were
configured as sortable:
#{inspect(illegal_fields)}
Use alias fields if you want to implement custom sorting.
"""
end
end
defp validate_no_duplicate_fields!(fields) do
duplicates = duplicate_fields(fields)
if duplicates != [] do
raise ArgumentError, """
duplicate fields
Alias field, compound field and join field names must be unique. These
field names were used multiple times:
#{inspect(duplicates)}
"""
end
end
defp duplicate_fields(fields) do
fields
|> Enum.frequencies()
|> Enum.filter(fn {_, count} -> count > 1 end)
|> Enum.map(fn {field, _} -> field end)
end
defp check_legacy_default_order(opts) do
if order_by = Keyword.get(opts, :default_order_by) do
directions = Keyword.get(opts, :default_order_directions)
raise """
The default order needs to be updated.
Please change your schema config to:
@derive {
Flop.Schema,
# ...
default_order: %{
order_by: #{inspect(order_by)},
order_directions: #{inspect(directions)}
}
}
"""
end
end
def normalize_custom_opts({name, opts}) when is_list(opts) do
opts = %{
filter: Keyword.fetch!(opts, :filter),
ecto_type: Keyword.get(opts, :ecto_type)
}
{name, opts}
end
def normalize_join_opts({name, opts}) do
opts =
case opts do
{binding, field} ->
%{
binding: binding,
field: field,
path: [binding, field],
ecto_type: nil
}
opts when is_list(opts) ->
binding = Keyword.fetch!(opts, :binding)
field = Keyword.fetch!(opts, :field)
%{
binding: binding,
field: field,
path: opts[:path] || [binding, field],
ecto_type: Keyword.get(opts, :ecto_type)
}
end
{name, opts}
end
def build_field_type_func(
compound_fields,
join_fields,
alias_fields,
custom_fields
) do
compound_field_funcs = field_type_funcs(:compound, compound_fields)
join_field_funcs = field_type_funcs(:join, join_fields)
alias_field_funcs = field_type_funcs(:alias, alias_fields)
custom_field_funcs = field_type_funcs(:custom, custom_fields)
default_funcs =
quote do
def field_type(_, name) do
{:normal, name}
end
end
quote do
unquote(compound_field_funcs)
unquote(join_field_funcs)
unquote(alias_field_funcs)
unquote(custom_field_funcs)
unquote(default_funcs)
end
end
defp field_type_funcs(type, fields)
when type in [:compound, :join, :custom] do
for {name, value} <- fields do
quote do
def field_type(_, unquote(name)) do
{unquote(type), unquote(Macro.escape(value))}
end
end
end
end
defp field_type_funcs(:alias, fields) do
for name <- fields do
quote do
def field_type(_, unquote(name)) do
{:alias, unquote(name)}
end
end
end
end
def build_cursor_dynamic_func_compound(compound_fields) do
for {compound_field, _fields} <- compound_fields do
quote do
def cursor_dynamic(_, [{_, unquote(compound_field)}], _) do
Logger.warn(
"Flop: Cursor pagination is not supported for compound fields. Ignored."
)
true
end
def cursor_dynamic(
struct,
[{_, unquote(compound_field)} | tail],
cursor
) do
Logger.warn(
"Flop: Cursor pagination is not supported for compound fields. Ignored."
)
cursor_dynamic(struct, tail, cursor)
end
end
end
end
def build_cursor_dynamic_func_alias(alias_fields) do
for name <- alias_fields do
quote do
def cursor_dynamic(_, [{_, unquote(name)} | _], _) do
raise "alias fields are not supported in cursor pagination"
end
end
end
end
# credo:disable-for-next-line
def build_cursor_dynamic_func_join(join_fields) do
for {join_field, %{binding: binding, field: field}} <- join_fields do
bindings = Code.string_to_quoted!("[#{binding}: r]")
quote do
def cursor_dynamic(_, [{direction, unquote(join_field)}], cursor)
when direction in [:asc, :asc_nulls_first, :asc_nulls_last] do
field_cursor = cursor[unquote(join_field)]
if is_nil(field_cursor) do
true
else
dynamic(
unquote(bindings),
field(r, unquote(field)) > ^field_cursor
)
end
end
def cursor_dynamic(_, [{direction, unquote(join_field)}], cursor)
when direction in [:desc, :desc_nulls_first, :desc_nulls_last] do
field_cursor = cursor[unquote(join_field)]
if is_nil(field_cursor) do
true
else
dynamic(
unquote(bindings),
field(r, unquote(field)) < ^field_cursor
)
end
end
def cursor_dynamic(
struct,
[{direction, unquote(join_field)} | [{_, _} | _] = tail],
cursor
) do
field_cursor = cursor[unquote(join_field)]
if is_nil(field_cursor) do
cursor_dynamic(struct, tail, cursor)
else
case direction do
dir when dir in [:asc, :asc_nulls_first, :asc_nulls_last] ->
dynamic(
unquote(bindings),
field(r, unquote(field)) >= ^field_cursor and
(field(r, unquote(field)) > ^field_cursor or
^cursor_dynamic(struct, tail, cursor))
)
dir when dir in [:desc, :desc_nulls_first, :desc_nulls_last] ->
dynamic(
unquote(bindings),
field(r, unquote(field)) <= ^field_cursor and
(field(r, unquote(field)) < ^field_cursor or
^cursor_dynamic(struct, tail, cursor))
)
end
end
end
end
end
end
# credo:disable-for-next-line
def build_cursor_dynamic_func_normal do
quote do
def cursor_dynamic(_, [{direction, field}], cursor) do
field_cursor = cursor[field]
if is_nil(field_cursor) do
true
else
case direction do
dir when dir in [:asc, :asc_nulls_first, :asc_nulls_last] ->
dynamic([r], field(r, ^field) > ^cursor[field])
dir when dir in [:desc, :desc_nulls_first, :desc_nulls_last] ->
dynamic([r], field(r, ^field) < ^cursor[field])
end
end
end
def cursor_dynamic(
struct,
[{direction, field} | [{_, _} | _] = tail],
cursor
) do
field_cursor = cursor[field]
if is_nil(field_cursor) do
Flop.Schema.cursor_dynamic(struct, tail, cursor)
else
case direction do
dir when dir in [:asc, :asc_nulls_first, :asc_nulls_last] ->
dynamic(
[r],
field(r, ^field) >= ^field_cursor and
(field(r, ^field) > ^field_cursor or
^Flop.Schema.cursor_dynamic(struct, tail, cursor))
)
dir when dir in [:desc, :desc_nulls_first, :desc_nulls_last] ->
dynamic(
[r],
field(r, ^field) <= ^field_cursor and
(field(r, ^field) < ^field_cursor or
^Flop.Schema.cursor_dynamic(struct, tail, cursor))
)
end
end
end
end
end
def build_order_by_func(compound_fields, join_fields, alias_fields) do
compound_field_funcs =
for {name, fields} <- compound_fields do
quote do
def apply_order_by(struct, q, {direction, unquote(name)}) do
Enum.reduce(unquote(fields), q, fn field, acc_q ->
Flop.Schema.apply_order_by(struct, acc_q, {direction, field})
end)
end
end
end
join_field_funcs =
for {join_field, %{binding: binding, field: field}} <- join_fields do
bindings = Code.string_to_quoted!("[#{binding}: r]")
quote do
def apply_order_by(_struct, q, {direction, unquote(join_field)}) do
order_by(
q,
unquote(bindings),
[{^direction, field(r, unquote(field))}]
)
end
end
end
alias_field_func =
for name <- alias_fields do
quote do
def apply_order_by(_struct, q, {direction, unquote(name)}) do
order_by(q, [{^direction, selected_as(unquote(name))}])
end
end
end
normal_field_func =
quote do
def apply_order_by(_struct, q, direction) do
order_by(q, ^direction)
end
end
quote do
unquote(compound_field_funcs)
unquote(join_field_funcs)
unquote(alias_field_func)
unquote(normal_field_func)
end
end
def build_get_field_func(compound_fields, join_fields) do
compound_field_funcs =
for {name, fields} <- compound_fields do
quote do
def get_field(struct, unquote(name)) do
Enum.map_join(
unquote(fields),
" ",
&Flop.Schema.get_field(struct, &1)
)
end
end
end
join_field_funcs =
for {name, %{path: path}} <- join_fields do
quote do
def get_field(struct, unquote(name)) do
Enum.reduce(unquote(path), struct, fn field, acc ->
case acc do
%{} -> Map.get(acc, field)
_ -> nil
end
end)
# assoc = Map.get(struct, unquote(assoc_field)) || %{}
# Map.get(assoc, unquote(field))
end
end
end
fallback_func =
quote do
def get_field(struct, field), do: Map.get(struct, field)
end
quote do
unquote(compound_field_funcs)
unquote(join_field_funcs)
unquote(fallback_func)
end
end
function_names = [
:default_limit,
:default_order,
:filterable,
:max_limit,
:pagination_types,
:sortable
]
for function_name <- function_names do
def unquote(function_name)(struct) do
raise Protocol.UndefinedError,
protocol: @protocol,
value: struct,
description: @instructions
end
end
def field_type(struct, _) do
raise Protocol.UndefinedError,
protocol: @protocol,
value: struct,
description: @instructions
end
def apply_order_by(struct, _, _) do
raise Protocol.UndefinedError,
protocol: @protocol,
value: struct,
description: @instructions
end
def cursor_dynamic(struct, _, _) do
raise Protocol.UndefinedError,
protocol: @protocol,
value: struct,
description: @instructions
end
# add default implementation for maps, so that cursor value functions can use
# it without checking protocol implementation
def get_field(%{} = map, field), do: Map.get(map, field)
def get_field(thing, _) do
raise Protocol.UndefinedError,
protocol: @protocol,
value: thing,
description: @instructions
end
end
