View Source Ash.Resource.Change behaviour (ash v3.4.44)

The behaviour for an action-specific resource change.

init/1 is defined automatically by use Ash.Resource.Change, but can be implemented if you want to validate/transform any options passed to the module.

The main function is change/3. It takes the changeset, any options that were provided when this change was configured on a resource, and the context, which currently only has the actor.

Summary

Callbacks

Runs on each batch result after it is dispatched to the data layer.

Whether or not batch callbacks should be run (if they are defined). Defaults to true.

Replaces change/3 for batch actions, allowing to optimize changes for bulk actions.

Runs on each batch before it is dispatched to the data layer.

Types

context()

@type context() :: Ash.Resource.Change.Context.t()

ref()

@type ref() :: {module(), Keyword.t()} | module()

t()

@type t() :: %Ash.Resource.Change{
  always_atomic?: term(),
  change: term(),
  description: term(),
  on: term(),
  only_when_valid?: term(),
  where: term()
}

Callbacks

after_batch(changesets_and_results, opts, context)

(optional)
@callback after_batch(
  changesets_and_results :: [{Ash.Changeset.t(), Ash.Resource.record()}],
  opts :: Keyword.t(),
  context :: Ash.Resource.Change.Context.t()
) ::
  :ok
  | Enumerable.t(
      {:ok, Ash.Resource.record()}
      | {:error, Ash.Error.t()}
      | Ash.Notifier.Notification.t()
    )

Runs on each batch result after it is dispatched to the data layer.

atomic(changeset, opts, context)

(optional)
@callback atomic(
  changeset :: Ash.Changeset.t(),
  opts :: Keyword.t(),
  context :: Ash.Resource.Change.Context.t()
) ::
  {:ok, Ash.Changeset.t()}
  | {:atomic, %{optional(atom()) => Ash.Expr.t() | {:atomic, Ash.Expr.t()}}}
  | {:atomic, Ash.Changeset.t(), %{optional(atom()) => Ash.Expr.t()}}
  | {:atomic, Ash.Changeset.t(), %{optional(atom()) => Ash.Expr.t()},
     [
       {:atomic, involved_fields :: [atom()] | :*,
        condition_expr :: Ash.Expr.t(), error_expr :: Ash.Expr.t()}
     ]}
  | {:not_atomic, String.t()}
  | :ok
  | {:error, term()}

atomic?()

@callback atomic?() :: boolean()

batch_callbacks?(changesets_or_query, opts, context)

@callback batch_callbacks?(
  changesets_or_query :: [Ash.Changeset.t()] | Ash.Query.t(),
  opts :: Keyword.t(),
  context :: Ash.Resource.Change.Context.t()
) :: boolean()

Whether or not batch callbacks should be run (if they are defined). Defaults to true.

batch_change(changesets, opts, context)

(optional)
@callback batch_change(
  changesets :: [Ash.Changeset.t()],
  opts :: Keyword.t(),
  context :: Ash.Resource.Change.Context.t()
) :: Enumerable.t(Ash.Changeset.t())

Replaces change/3 for batch actions, allowing to optimize changes for bulk actions.

You can define only batch_change/3, and it will be used for both single and batch actions. It cannot, however, be used in place of the atomic/3 callback.

before_batch(changesets, opts, context)

(optional)
@callback before_batch(
  changesets :: [Ash.Changeset.t()],
  opts :: Keyword.t(),
  context :: Ash.Resource.Change.Context.t()
) :: Enumerable.t(Ash.Changeset.t() | Ash.Notifier.Notification.t())

Runs on each batch before it is dispatched to the data layer.

change(changeset, opts, context)

(optional)
@callback change(
  changeset :: Ash.Changeset.t(),
  opts :: Keyword.t(),
  context :: Ash.Resource.Change.Context.t()
) :: Ash.Changeset.t()

has_after_batch?()

@callback has_after_batch?() :: boolean()

has_batch_change?()

@callback has_batch_change?() :: boolean()

has_before_batch?()

@callback has_before_batch?() :: boolean()

has_change?()

@callback has_change?() :: boolean()

init(opts)

@callback init(opts :: Keyword.t()) :: {:ok, Keyword.t()} | {:error, term()}