add relationship level links and meta options

lib/active_model/serializer/adapter/json_api.rb

@@ -173,9 +173,41 @@ def relationship_value_for(serializer, options = {})
           end
         end
 
+        def relationship_links_for(name, owner, options = {})
+          options[:links].each_with_object({}) do |(key, link), hash|
+            if link.is_a? Proc
+              hash[key] = link.call(owner, name)
+            else
+              hash[key] = link
+            end
+
+            hash
+          end
+        end
+
+        def relationship_meta_for(name, owner, options = {})
+          if options[:meta].is_a? Proc
+            options[:meta].call(owner, name)
+          else
+            options[:meta]
+          end
+        end
+
         def relationships_for(serializer)
           serializer.associations.each_with_object({}) do |association, hash|
-            hash[association.key] = { data: relationship_value_for(association.serializer, association.options) }
+            hash[association.key] = {}
+
+            if association.options.fetch(:data, true)
+              hash[association.key][:data] = relationship_value_for(association.serializer, association.options)
+            end
+
+            if association.options.fetch(:links, false)
+              hash[association.key][:links] = relationship_links_for(association.name, serializer.object, association.options)
+            end
+
+            if association.options.fetch(:meta, false)
+              hash[association.key][:meta] = relationship_meta_for(association.name, serializer.object, association.options)
+            end
           end
         end
 

test/adapter/json_api/has_many_links_test.rb

@@ -0,0 +1,74 @@
+require 'test_helper'
+
+module ActionController
+  module Serialization
+    class JsonApiHasManyLinksTest < ActionController::TestCase
+      LinkTagSerializer = Class.new(ActiveModel::Serializer) do
+        has_many :posts, links: { related: -> (object, name) { "http://test.host/tags/#{object.id}/#{name}" } }, data: false
+      end
+
+      class MyController < ActionController::Base
+        def render_resource_with_has_many_association
+          @tag = Tag.new(id: 1)
+          @tag.posts = []
+          render json: @tag, adapter: :json_api, serializer: LinkTagSerializer
+        end
+      end
+
+      tests MyController
+
+      def test_render_resource_with_has_many_association
+        get :render_resource_with_has_many_association
+        expected = {
+          data: {
+            id: '1',
+            type: 'tags',
+            relationships: {
+              posts: {
+                links: {
+                  related: 'http://test.host/tags/1/posts'
+                }
+              }
+            }
+          }
+        }
+        assert_equal expected.to_json, response.body
+      end
+    end
+
+    class JsonApiHasManyLinksWithDataTest < ActionController::TestCase
+      LinkTagSerializer = Class.new(ActiveModel::Serializer) do
+        has_many :posts, links: { related: -> (object, name) { "http://test.host/tags/#{object.id}/#{name}" } }
+      end
+
+      class MyController < ActionController::Base
+        def render_resource_with_has_many_association
+          @tag = Tag.new(id: 1)
+          @tag.posts = []
+          render json: @tag, adapter: :json_api, serializer: LinkTagSerializer
+        end
+      end
+
+      tests MyController
+
+      def test_render_resource_with_has_many_association
+        get :render_resource_with_has_many_association
+        expected = {
+          data: {
+            id: '1',
+            type: 'tags',
+            relationships: {
+              posts: {
+                data: [],
+                links: {
+                  related: 'http://test.host/tags/1/posts'
+                }
+              }
+            }
+          }
+        }
+        assert_equal expected.to_json, response.body
+      end
+    end
+  end
+end

test/adapter/json_api/has_many_meta_test.rb

@@ -0,0 +1,40 @@
+require 'test_helper'
+
+module ActionController
+  module Serialization
+    class JsonApiHasManyMetaTest < ActionController::TestCase
+      MetaTagSerializer = Class.new(ActiveModel::Serializer) do
+        has_many :posts, meta: -> (_object, _name) { { page: '1' } }
+      end
+
+      class MyController < ActionController::Base
+        def render_resource_with_has_many_association
+          @tag = Tag.new(id: 1)
+          @tag.posts = []
+          render json: @tag, adapter: :json_api, serializer: MetaTagSerializer
+        end
+      end
+
+      tests MyController
+
+      def test_render_resource_with_has_many_association
+        get :render_resource_with_has_many_association
+        expected = {
+          data: {
+            id: '1',
+            type: 'tags',
+            relationships: {
+              posts: {
+                data: [],
+                meta: {
+                  page: '1'
+                }
+              }
+            }
+          }
+        }
+        assert_equal expected.to_json, response.body
+      end
+    end
+  end
+end

test/adapter/json_api/has_one_links_test.rb

@@ -0,0 +1,74 @@
+require 'test_helper'
+
+module ActionController
+  module Serialization
+    class JsonApiHasOneLinksTest < ActionController::TestCase
+      LinkTagSerializer = Class.new(ActiveModel::Serializer) do
+        has_one :post, links: { related: -> (object, name) { "http://test.host/tags/#{object.id}/#{name}" } }, data: false
+      end
+
+      class MyController < ActionController::Base
+        def render_resource_with_has_one_association
+          @tag = Tag.new(id: 1)
+          @tag.post = Post.new(id: 1)
+          render json: @tag, adapter: :json_api, serializer: LinkTagSerializer
+        end
+      end
+
+      tests MyController
+
+      def test_render_resource_with_has_one_association
+        get :render_resource_with_has_one_association
+        expected = {
+          data: {
+            id: '1',
+            type: 'tags',
+            relationships: {
+              post: {
+                links: {
+                  related: 'http://test.host/tags/1/post'
+                }
+              }
+            }
+          }
+        }
+        assert_equal expected.to_json, response.body
+      end
+    end
+
+    class JsonApiHasOneLinksWithDataTest < ActionController::TestCase
+      LinkTagSerializer = Class.new(ActiveModel::Serializer) do
+        has_one :post, links: { related: -> (object, name) { "http://test.host/tags/#{object.id}/#{name}" } }
+      end
+
+      class MyController < ActionController::Base
+        def render_resource_with_has_one_association
+          @tag = Tag.new(id: 1)
+          @tag.post = Post.new(id: 1)
+          render json: @tag, adapter: :json_api, serializer: LinkTagSerializer
+        end
+      end
+
+      tests MyController
+
+      def test_render_resource_with_has_one_association
+        get :render_resource_with_has_one_association
+        expected = {
+          data: {
+            id: '1',
+            type: 'tags',
+            relationships: {
+              post: {
+                data: { id: '1', type: 'posts' },
+                links: {
+                  related: 'http://test.host/tags/1/post'
+                }
+              }
+            }
+          }
+        }
+        assert_equal expected.to_json, response.body
+      end
+    end
+  end
+end

test/adapter/json_api/has_one_meta_test.rb

@@ -0,0 +1,40 @@
+require 'test_helper'
+
+module ActionController
+  module Serialization
+    class JsonApiHasOneMetaTest < ActionController::TestCase
+      MetaTagSerializer = Class.new(ActiveModel::Serializer) do
+        has_one :post, meta: -> (_object, _name) { { deleted: true } }
+      end
+
+      class MyController < ActionController::Base
+        def render_resource_with_has_one_association
+          @tag = Tag.new(id: 1)
+          @tag.post = Post.new(id: 1)
+          render json: @tag, adapter: :json_api, serializer: MetaTagSerializer
+        end
+      end
+
+      tests MyController
+
+      def test_render_resource_with_has_one_association
+        get :render_resource_with_has_one_association
+        expected = {
+          data: {
+            id: '1',
+            type: 'tags',
+            relationships: {
+              post: {
+                data: { id: '1', type: 'posts' },
+                meta: {
+                  deleted: true
+                }
+              }
+            }
+          }
+        }
+        assert_equal expected.to_json, response.body
+      end
+    end
+  end
+end