# AshUlid
[](https://hex.pm/packages/ash_ulid)
[](https://hexdocs.pm/ash_ulid/)
[](https://github.com/vonagam/ash_ulid/blob/master/LICENSE.md)
`Ash.Type` implementation for [ULID](https://github.com/ulid/spec).
Consists of three modules:
- `AshUlid` - utility functions to generate ULIDs.
- `AshUlid.Type` - `Ash.Type` implementation.
- `AshUlid.Extension` - `ulid_primary_key` shortcut.
## Installation
Add to the deps, get deps (`mix deps.get`), compile them (`mix deps.compile`).
```elixir
def deps do
[
{:ash_ulid, "~> 0.2.1"},
]
end
```
## Usage
### Primary key
To use as a primary key in `Ash.Resource` it is recommended to add `AshUlid.Extension` that provides `ulid_primary_key`:
```elixir
defmodule Example.Resource do
use Ash.Resource,
extensions: [AshUlid.Extension]
attributes do
ulid_primary_key :id
end
end
```
Which is a shortcut for this:
```elixir
uuid_primary_key :id, type: AshUlid.Type, default: &AshUlid.generate/0
```
To prevent formatter from adding parens to `ulid_primary_key` add `:ash_ulid` to `import_deps` in `.formatter.exs`.
If you plan to use ULID as a main type for primary keys it makes sense to set it as `default_belongs_to_type` in a config:
```elixir
config :ash, default_belongs_to_type: AshUlid.Type
```
### Attribute type
`AshUlid.Type` can be registered under `ulid` name in a config:
```elixir
config :ash, custom_types: [ulid: AshUlid.Type]
```
And then used like this:
```elixir
defmodule Example.Another do
use Ash.Resource
attributes do
attribute :key, :ulid
end
relationships do
belongs_to :resource, Example.Resource, attribute_type: :ulid
end
end
```
Without an alias it is the same, just replace `:ulid` with `AshUlid.Type`.
If `default_belongs_to_type` is set then `attribute_type: :ulid` in this example is not needed.
### Generate
To generate ULID call `AshUlid.generate/0` or `AshUlid.generate/1` with a specific timestamp.
## References
ULID spec can be found [here](https://github.com/ulid/spec).
The work is mostly based on [`Ecto.ULID`](https://github.com/TheRealReal/ecto-ulid).
