View Source Ash.Resource.Change.Builtins (ash v2.4.12)

Built in changes that are available to all resources

The functions in this module are imported by default in the actions section.

Link to this section Summary

Functions

Passes the provided value into changeset.api.load(), after the action has completed.

Calls Ash.Changeset.manage_relationship/4 with the changeset and relationship provided, using the value provided for the named argument.

Clears a change off of the changeset before the action runs.

Relates the actor to the data being changed, as the provided relationship.

Passes the provided value into Ash.Changeset.select/3

Sets the attribute to the value provided.

Merges the given query context.

Sets the attribute to the value provided if the attribute is not already being changed.

Link to this section Functions

@spec ensure_selected(select :: atom() | [atom()]) :: Ash.Resource.Change.ref()

Passes the provided value into Ash.Changeset.ensure_selected/2

If the value is not already selected, this makes sure it is. Does not deselect anything else.

example

Example

change ensure_selected([:necessary_field])

@spec load(load :: term()) :: Ash.Resource.Change.ref()

Passes the provided value into changeset.api.load(), after the action has completed.

example

Example

change load(:comments)
change load([:friend_count, :friends])
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manage_relationship(argument, relationship_name \\ nil, opts)

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@spec manage_relationship(
  argument :: atom(),
  relationship_name :: atom() | nil,
  opts :: Keyword.t()
) :: Ash.Resource.Change.ref()

Calls Ash.Changeset.manage_relationship/4 with the changeset and relationship provided, using the value provided for the named argument.

If relationship_name is not specified, it is assumed to be the same as the argument.

For information on the available options, see Ash.Changeset.manage_relationship/4.

examples

Examples

change manage_relationship(:comments, type: :append)
change manage_relationship(:remove_comments, :comments, type: :remove)
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prevent_change(attribute)

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@spec prevent_change(attribute :: atom()) :: Ash.Resource.Change.ref()

Clears a change off of the changeset before the action runs.

Does not fail if it is being changed, but ensures it is cleared just before the action.

Can be useful if a change is only used in validations but shouldn't ultimately be written to the data layer.

examples

Examples

change prevent_change(:email)
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relate_actor(relationship, opts \\ [])

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@spec relate_actor(relationship :: atom(), opts :: Keyword.t()) ::
  Ash.Resource.Change.ref()

Relates the actor to the data being changed, as the provided relationship.

options

Options

  • :relationship - Required. The relationship to set the actor to.

  • :allow_nil? - Whether or not to allow the actor to be nil, in which case nothing will happen. The default value is false.

examples

Examples

change relate_actor(:owner, allow_nil?: true)
@spec select(select :: atom() | [atom()]) :: Ash.Resource.Change.ref()

Passes the provided value into Ash.Changeset.select/3

Keep in mind, this will limit the fields that are selected. You may want ensure_selected/1 if you want to make sure that something is selected, without deselecting anything else.

Selecting in changesets does not actually do a select in the data layer. It nils out any fields that were not selected after completing the action. This can be useful if you are writing policies that have to do with specific fields being selected.

example

Example

change select([:name])
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set_attribute(attribute, value)

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@spec set_attribute(
  relationship :: atom(),
  (() -> term()) | {:_arg, :status} | term()
) ::
  Ash.Resource.Change.ref()

Sets the attribute to the value provided.

If a zero argument function is provided, it is called to determine the value.

Use arg(:argument_name) to use the value of the given argument. If the argument is not supplied then nothing happens.

examples

Examples

change set_attribute(:active, false)
change set_attribute(:opened_at, &DateTime.utc_now/0)
change set_attribute(:status, arg(:status))
@spec set_context(context :: map() | mfa()) :: Ash.Resource.Change.ref()

Merges the given query context.

If an MFA is provided, it will be called with the changeset. The MFA should return {:ok, context_to_be_merged} or {:error, term}

examples

Examples

change set_context(%{something_used_internally: true})
change set_context({MyApp.Context, :set_context, []})
Link to this function

set_new_attribute(attribute, value)

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@spec set_new_attribute(
  relationship :: atom(),
  (() -> term()) | {:_arg, :status} | term()
) ::
  Ash.Resource.Change.ref()

Sets the attribute to the value provided if the attribute is not already being changed.

If a zero argument function is provided, it is called to determine the value.

Use arg(:argument_name) to use the value of the given argument. If the argument is not supplied then nothing happens.

examples

Examples

change set_new_attribute(:active, false)
change set_new_attribute(:opened_at, &DateTime.utc_now/0)
change set_new_attribute(:status, arg(:status))