Add ActiveModel::Serializer#default_include

lib/active_model/serializer.rb

@@ -100,13 +100,16 @@ def self.get_serializer_for(klass)
 
     # @api private
     def self.include_directive_from_options(options)
-      if options[:include_directive]
+      include_directive = if options[:include_directive]
         options[:include_directive]
       elsif options[:include]
         JSONAPI::IncludeDirective.new(options[:include], allow_wildcard: true)
       else
         ActiveModelSerializers.default_include_directive
       end
+      _default_include ?
+          include_directive.merge(_default_include) :
+          include_directive
     end
 
     # @api private
@@ -164,7 +167,7 @@ def success?
     #     serializer.as_json(include: { posts: { include: { comments: { only: :body } }, only: :title } })
     def serializable_hash(adapter_options = nil, options = {}, adapter_instance = self.class.serialization_adapter_instance)
       adapter_options ||= {}
-      options[:include_directive] ||= ActiveModel::Serializer.include_directive_from_options(adapter_options)
+      options[:include_directive] ||= self.class.include_directive_from_options(adapter_options)
       cached_attributes = adapter_options[:cached_attributes] ||= {}
       resource = fetch_attributes(options[:fields], cached_attributes, adapter_instance)
       relationships = resource_relationships(adapter_options, options, adapter_instance)

lib/active_model/serializer/associations.rb

@@ -12,7 +12,7 @@ module Associations
 
       included do
         with_options instance_writer: false, instance_reader: true do |serializer|
-          serializer.class_attribute :_reflections
+          serializer.class_attribute :_reflections, :_default_include, :_always_include
           self._reflections ||= []
         end
 
@@ -65,6 +65,26 @@ def has_one(name, options = {}, &block) # rubocop:disable Style/PredicateName
           associate(HasOneReflection.new(name, options, block))
         end
 
+        # Set _default_include to the parsed value of +include_args+.
+        # @param include_args value to be parsed by JSONAPI::IncludeDirective::Parser
+        # @param options options for JSONAPI::IncludeDirective::Parser, default { allow_wildcard: true }
+        # @return [void]
+        #
+        def default_include(include_args, options = {})
+          default_options = { allow_wildcard: true }
+          self._default_include = JSONAPI::IncludeDirective.new(include_args, default_options.merge(options))
+        end
+
+        # Set _always_include to the parsed value of +include_args+.
+        # @param include_args value to be parsed by JSONAPI::IncludeDirective::Parser
+        # @param options options for JSONAPI::IncludeDirective::Parser, default { allow_wildcard: true }
+        # @return [void]
+        #
+        def always_include(include_args, options = {})
+          default_options = { allow_wildcard: true }
+          self._always_include = JSONAPI::IncludeDirective.new(include_args, default_options.merge(options))
+        end
+
         private
 
         # Add reflection and define {name} accessor.
@@ -74,17 +94,29 @@ def has_one(name, options = {}, &block) # rubocop:disable Style/PredicateName
         # @api private
         #
         def associate(reflection)
-          self._reflections << reflection
+          _reflections << reflection
         end
       end
 
+      # Instance method to get _default_include
+      def default_include
+        _default_include
+      end
+
+      # Instance method to get _always_include
+      def always_include
+        _always_include
+      end
+
       # @param [JSONAPI::IncludeDirective] include_directive (defaults to the
       #   +default_include_directive+ config value when not provided)
       # @return [Enumerator<Association>]
       #
       def associations(include_directive = ActiveModelSerializers.default_include_directive)
         return unless object
 
+        include_directive.merge!(always_include) if always_include
+
         Enumerator.new do |y|
           self.class._reflections.each do |reflection|
             next if reflection.excluded?(self)

lib/active_model_serializers/adapter/json_api.rb

@@ -236,7 +236,12 @@ def resource_objects_for(serializers)
         @included = []
         @resource_identifiers = Set.new
         serializers.each { |serializer| process_resource(serializer, true) }
-        serializers.each { |serializer| process_relationships(serializer, @include_directive) }
+        serializers.each do |serializer|
+          include_directive = serializer.default_include ?
+              @include_directive.merge(serializer.default_include) :
+              @include_directive
+          process_relationships(serializer, include_directive)
+        end
 
         [@primary, @included]
       end

test/serializers/always_include_test.rb

@@ -0,0 +1,79 @@
+require 'test_helper'
+
+module ActiveModel
+  class Serializer
+    class DefaultIncludeTest < ActiveSupport::TestCase
+      class Blog < ActiveModelSerializers::Model
+        attr_accessor :id, :name, :posts
+      end
+      class Post < ActiveModelSerializers::Model
+        attr_accessor :id, :title, :author, :category
+      end
+      class Author < ActiveModelSerializers::Model
+        attr_accessor :id, :name
+      end
+      class Category < ActiveModelSerializers::Model
+        attr_accessor :id, :name
+      end
+
+      class BlogSerializer < ActiveModel::Serializer
+        always_include 'posts'
+        attributes :id
+        attribute :name, key: :title
+
+        has_many :posts
+      end
+      class PostSerializer < ActiveModel::Serializer
+        always_include 'author'
+        attributes :id, :title
+
+        has_one :author
+        has_one :category
+      end
+      class AuthorSerializer < ActiveModel::Serializer
+        attributes :id, :name
+      end
+      class CategorySerializer < ActiveModel::Serializer
+        attributes :id, :name
+      end
+
+      setup do
+        @authors = [Author.new(id: 1, name: 'Blog Author')]
+        @categories = [Category.new(id: 1, name: 'Food')]
+        @posts = [
+            Post.new(id: 1, title: 'The first post', author: @authors.first, category: @categories.first),
+            Post.new(id: 2, title: 'The second post', author: @authors.first, category: @categories.first)]
+        @blog = Blog.new(id: 2, name: 'The Blog', posts: @posts)
+      end
+
+      test '#always_include option populate "included" for json_api adapter' do
+        serialized = ActiveModelSerializers::SerializableResource.new(@blog, serializer: BlogSerializer, adapter: :json_api).as_json
+
+        assert_equal serialized[:included].size, 3
+        assert_equal 'The first post', serialized[:included].first[:attributes][:title]
+      end
+
+      test '#always_include merges with the render include for json_api adapter' do
+        serialized = ActiveModelSerializers::SerializableResource.new(@blog, serializer: BlogSerializer, adapter: :json_api, include: 'posts.category').as_json
+
+        assert_equal serialized[:included].size, 4
+        assert_equal 'The first post', serialized[:included].first[:attributes][:title]
+      end
+
+      test '#always_include option include associations for attributes adapter' do
+        serialized = ActiveModelSerializers::SerializableResource.new(@blog, serializer: BlogSerializer, adapter: :attributes).as_json
+
+        assert_equal serialized[:posts].size, 2
+        assert_equal 'Blog Author', serialized[:posts].first[:author][:name]
+      end
+
+      test '#always_include merges with the render include for attributes adapter' do
+        serialized = ActiveModelSerializers::SerializableResource.new(@blog, serializer: BlogSerializer, adapter: :attributes, include: 'posts.category').as_json
+
+        assert_equal serialized[:posts].size, 2
+        assert_equal 'Blog Author', serialized[:posts].first[:author][:name]
+        assert_equal 'Food', serialized[:posts].first[:category][:name]
+      end
+    end
+  end
+end

test/serializers/default_include_test.rb

@@ -0,0 +1,79 @@
+require 'test_helper'
+
+module ActiveModel
+  class Serializer
+    class DefaultIncludeTest < ActiveSupport::TestCase
+      class Blog < ActiveModelSerializers::Model
+        attr_accessor :id, :name, :posts
+      end
+      class Post < ActiveModelSerializers::Model
+        attr_accessor :id, :title, :author, :category
+      end
+      class Author < ActiveModelSerializers::Model
+        attr_accessor :id, :name
+      end
+      class Category < ActiveModelSerializers::Model
+        attr_accessor :id, :name
+      end
+
+      class BlogSerializer < ActiveModel::Serializer
+        default_include 'posts.author'
+        attributes :id
+        attribute :name, key: :title
+
+        has_many :posts
+      end
+      class PostSerializer < ActiveModel::Serializer
+        default_include 'author'
+        attributes :id, :title
+
+        has_one :author
+        has_one :category
+      end
+      class AuthorSerializer < ActiveModel::Serializer
+        attributes :id, :name
+      end
+      class CategorySerializer < ActiveModel::Serializer
+        attributes :id, :name
+      end
+
+      setup do
+        @authors = [Author.new(id: 1, name: 'Blog Author')]
+        @categories = [Category.new(id: 1, name: 'Food')]
+        @posts = [
+            Post.new(id: 1, title: 'The first post', author: @authors.first, category: @categories.first),
+            Post.new(id: 2, title: 'The second post', author: @authors.first, category: @categories.first)]
+        @blog = Blog.new(id: 2, name: 'The Blog', posts: @posts)
+      end
+
+      test '#default_include option populate "included" for json_api adapter' do
+        serialized = ActiveModelSerializers::SerializableResource.new(@blog, serializer: BlogSerializer, adapter: :json_api).as_json
+
+        assert_equal serialized[:included].size, 3
+        assert_equal 'The first post', serialized[:included].first[:attributes][:title]
+      end
+
+      test '#default_include merges with the render include for json_api adapter' do
+        serialized = ActiveModelSerializers::SerializableResource.new(@blog, serializer: BlogSerializer, adapter: :json_api, include: 'posts.category').as_json
+
+        assert_equal serialized[:included].size, 4
+        assert_equal 'The first post', serialized[:included].first[:attributes][:title]
+      end
+
+      test '#default_include option include associations for attributes adapter' do
+        serialized = ActiveModelSerializers::SerializableResource.new(@blog, serializer: BlogSerializer, adapter: :attributes).as_json
+
+        assert_equal serialized[:posts].size, 2
+        assert_equal 'Blog Author', serialized[:posts].first[:author][:name]
+      end
+
+      test '#default_include merges with the render include for attributes adapter' do
+        serialized = ActiveModelSerializers::SerializableResource.new(@blog, serializer: BlogSerializer, adapter: :attributes, include: 'posts.category').as_json
+
+        assert_equal serialized[:posts].size, 2
+        assert_equal 'Blog Author', serialized[:posts].first[:author][:name]
+        assert_equal 'Food', serialized[:posts].first[:category][:name]
+      end
+    end
+  end
+end