Provides helper functions for analyzing Ash actions.

This module contains language-agnostic utilities for determining action characteristics, enabling code generators to produce appropriate client code for different action types.

Features

• Pagination Analysis - Detect offset, keyset, required, and countable pagination
• Input Requirements - Determine if actions require, optionally accept, or have no input
• Return Type Classification - Identify field-selectable return types for generic actions

Usage

Pagination Support

alias AshIntrospection.Codegen.ActionIntrospection

action = AshIntrospection.ResourceInfo.action(MyApp.Post, :list)

if ActionIntrospection.action_supports_pagination?(action) do
  # Generate paginated response type
  if ActionIntrospection.action_supports_offset_pagination?(action) do
    # Include offset/limit parameters
  end
  if ActionIntrospection.action_supports_keyset_pagination?(action) do
    # Include after/before parameters
  end
end

Input Requirements

case ActionIntrospection.action_input_type(resource, action) do
  :required -> # Generate required input parameter
  :optional -> # Generate optional input parameter
  :none     -> # No input parameter needed
end

# Get specific field lists
required_fields = ActionIntrospection.get_required_inputs(resource, action)
optional_fields = ActionIntrospection.get_optional_inputs(resource, action)

Generic Action Return Types

case ActionIntrospection.action_returns_field_selectable_type?(action) do
  {:ok, :resource, MyApp.User} ->
    # Returns a single User, can select fields

  {:ok, :array_of_resource, MyApp.User} ->
    # Returns array of Users, can select fields

  {:ok, :typed_map, fields} ->
    # Returns map with typed fields, can select from field list

  {:ok, :unconstrained_map, nil} ->
    # Returns map without constraints, no field selection

  {:error, :not_field_selectable_type} ->
    # Returns primitive type, no field selection

  {:error, :not_generic_action} ->
    # Not a generic action (use standard CRUD handling)
end

Design Notes

The return type analysis uses a type-driven classification pattern with classify_return_type/2 for consistent handling of all type variants including resources, typed maps, typed structs, and primitives.