Describes how to convert data to Ecto.Type and eventually into the database.

This behaviour is a superset of the Ecto.Type behaviour, that also contains API level information, like what kinds of filters are allowed.

built-in-types

Built in types

• :map - Ash.Type.Map
• :term - Ash.Type.Term
• :atom - Ash.Type.Atom
• :string - Ash.Type.String
• :integer - Ash.Type.Integer
• :float - Ash.Type.Float
• :duration_name - Ash.Type.DurationName
• :function - Ash.Type.Function
• :boolean - Ash.Type.Boolean
• :struct - Ash.Type.Struct
• :uuid - Ash.Type.UUID
• :binary - Ash.Type.Binary
• :date - Ash.Type.Date
• :time - Ash.Type.Time
• :decimal - Ash.Type.Decimal
• :ci_string - Ash.Type.CiString
• :naive_datetime - Ash.Type.NaiveDatetime
• :utc_datetime - Ash.Type.UtcDatetime
• :utc_datetime_usec - Ash.Type.UtcDatetimeUsec
• :url_encoded_binary - Ash.Type.UrlEncodedBinary
• :union - Ash.Type.Union
• :module - Ash.Type.Module

composite-types

Composite Types

Currently, the only composite type supported is a list type, specified via: {:array, Type}. The constraints available are:

• :items (term/0) - Constraints for the elements of the list. See the contained type's docs for more.

• :min_length (non_neg_integer/0) - A minimum length for the items

• :max_length (non_neg_integer/0) - A maximum length for the items

• :nil_items? (boolean/0) - Whether or not the list can contain nil items The default value is false.

• :empty_values (list of term/0) - A set of values that, if encountered, will be considered an empty list. The default value is [""].

defining-custom-types

Defining Custom Types

Generally you add use Ash.Type to your module (it is possible to add @behaviour Ash.Type and define everything yourself, but this is more work and error-prone).

Overriding the {:array, type} behaviour. By defining the *_array versions of cast_input, cast_stored, dump_to_native and apply_constraints, you can override how your type behaves as a collection. This is how the features of embedded resources are implemented. No need to implement them unless you wish to override the default behaviour.

Simple example of a float custom type

defmodule GenTracker.AshFloat do
  use Ash.Type

  @impl Ash.Type
  def storage_type, do: :float

  @impl Ash.Type
  def cast_input(value, _) do
    Ecto.Type.cast(:float, value)
  end

  @impl Ash.Type
  def cast_stored(value, _) do
    Ecto.Type.load(:float, value)
  end

  @impl Ash.Type
  def dump_to_native(value, _) do
    Ecto.Type.dump(:float, value)
  end
end

All the Ash built-in types are implemented with use Ash.Type so they are good examples to look at to create your own Ash.Type.

short-names

Short names

You can define short :atom_names for your custom types by adding them to your Ash configuration:

config :ash, :custom_types, [ash_float: GenTracker.AshFloat]

Doing this will require a recompilation of the :ash dependency which can be triggered by calling:

$ mix deps.compile ash --force