Processes requested fields for Ash resources, determining which fields should be selected vs loaded, and building extraction templates for result processing.
This module handles different action types:
- CRUD actions (:read, :create, :update, :destroy) return resource records
- Generic actions (:action) return arbitrary types as specified in their
returnsfield
Architecture
This module serves as the main entry point and delegates to FieldSelector,
which uses a unified type-driven recursive dispatch pattern (similar to ValueFormatter).
The key insight is that each type is self-describing via {type, constraints},
so no separate classification step is needed.
Summary
Functions
Atomizes requested fields by converting standalone strings to atoms and map keys to atoms.
Processes requested fields for a given resource and action.
Functions
Atomizes requested fields by converting standalone strings to atoms and map keys to atoms.
Uses the configured input field formatter to properly parse field names from client format to internal format before converting to atoms.
When a resource is provided, field_names DSL mappings are checked first to handle custom client→internal field name mappings.
Parameters
requested_fields- List of strings/atoms or maps for relationshipsresource- Optional resource module for field_names DSL lookup
Examples
iex> atomize_requested_fields(["id", "title", %{"user" => ["id", "name"]}])
[:id, :title, %{user: [:id, :name]}]
iex> atomize_requested_fields([%{"self" => %{"args" => %{"prefix" => "test"}}}])
[%{self: %{args: %{prefix: "test"}}}]Processes requested fields for a given resource and action.
Returns {:ok, {select_fields, load_fields, extraction_template}} or {:error, error}.
Parameters
resource- The Ash resource moduleaction- The action name (atom)requested_fields- List of field atoms or maps for relationships
Examples
iex> process(MyApp.Todo, :read, [:id, :title, %{user: [:id, :name]}])
{:ok, {[:id, :title], [{:user, [:id, :name]}], [:id, :title, [user: [:id, :name]]]}}
iex> process(MyApp.Todo, :read, [%{user: [:invalid_field]}])
{:error, %{type: :invalid_field, field: "user.invalidField"}}