A type for abstracting enums into a single type.

For example, your existing attribute might look like:

attribute :status, :atom, constraints: [one_of: [:open, :closed]]copy

But as that starts to spread around your system, you may find that you want to centralize that logic. To do that, use this module to define an Ash type easily:

defmodule MyApp.TicketStatus do
  use Ash.Type.Enum, values: [:open, :closed]
endcopy

Then, you can rewrite your original attribute as follows:

attribute :status, MyApp.TicketStatuscopy

Valid values are:

• The atom itself, e.g :open
• A string that matches the atom, e.g "open"
• A string that matches the atom after being downcased, e.g "OPEN" or "oPeN"
• A string that matches the stringified, downcased atom, after itself being downcased. This allows for enum values like :Open, :SomeState and :Some_State

Value descriptions

It's possible to associate a description with a value by passing a {value, description} tuple inside the values list, which becomes a keyword list:

defmodule MyApp.TicketStatus do
  use Ash.Type.Enum,
    values: [
      open: "An open ticket",
      closed: "A closed ticket"
    ]
endcopy

This can be used by extensions to provide detailed descriptions of enum values.

The description of a value can be retrieved with description/1:

MyApp.TicketStatus.description(:open)
iex> "An open ticket"copy