View Source Ash.Type.NewType behaviour (ash v2.18.2)

Allows defining a new type that is the combination of an existing type and custom constraints

A subtle difference between this type and its supertype (one that will almost certainly not matter in any case) is that we use the apply_constraints logic of the underlying type in the same step as cast_input. We do this because new types like these are, generally speaking, considering the constraint application as part of the core type. Other types, if you simply do Ash.Type.cast_input/3 you will not be also applying their constraints.

For Example:

defmodule MyApp.Types.SSN do
  use Ash.Type.NewType, subtype_of: :string, constraints: [match: ~r/regex for ssn/]

defmodule MyApp.Types.Metadata do
  use Ash.Type.NewType, subtype_of: :union, constraints: [types: [
    foo: [...],
    bar: [...]



@type t() :: module() | atom() | {:array, module() | atom()}


@callback subtype_constraints() :: Keyword.t()
@callback subtype_of() :: module() | atom()
Link to this callback

type_constraints(constraints, subtype_constraints)

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@callback type_constraints(constraints :: Keyword.t(), subtype_constraints :: Keyword.t()) ::


Link to this function

constraints(type, constraints)

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@spec new_type?(Ash.Type.t()) :: boolean()
@spec subtype_of(t()) :: Ash.Type.t()