Merge pull request #461 from fivetanley/embed-in-root-key

Add embed_namespace and embed_in_root_key options

README.md

@@ -522,6 +522,33 @@ Now, any associations will be supplied as an Array of IDs:
 }
 ```
 
+You may also choose to embed the IDs by the association's name underneath an
+`embed_key` for the resource. For example, say we want to change `comment_ids`
+to `comments` underneath a `links` key:
+
+```ruby
+class PostSerializer < ActiveModel::Serializer
+  attributes :id, :title, :body
+
+  has_many :comments, embed: ids, embed_namespace: :links
+end
+```
+
+The JSON will look like this:
+
+```json
+{
+  "post": {
+    "id": 1,
+    "title": "New post",
+    "body": "A body!",
+    "links": {
+      "comments": [ 1, 2, 3 ]
+    }
+  }
+}
+```
+
 Alternatively, you can choose to embed only the ids or the associated objects per association:
 
 ```ruby
@@ -589,6 +616,42 @@ this:
 }
 ```
 
+If you would like to namespace association JSON underneath a certain key in
+the root document (say, `linked`), you can specify an `embed_in_root_key`:
+
+```ruby
+class PostSerializer < ActiveModel::Serializer
+  embed: ids, include: true, embed_in_root_key: :linked
+
+  attributes: :id, :title, :body
+  has_many :comments, :tags
+end
+```
+
+The above would yield the following JSON document:
+
+```json
+{
+  "post": {
+    "id": 1,
+    "title": "New post",
+    "body": "A body!",
+    "comment_ids": [ 1, 2 ]
+  },
+  "linked": {
+    "comments": [
+      { "id": 1, "body": "what a dumb post", "tag_ids": [ 1, 2 ] },
+      { "id": 2, "body": "i liked it", "tag_ids": [ 1, 3 ] },
+    ],
+    "tags": [
+      { "id": 1, "name": "short" },
+      { "id": 2, "name": "whiny" },
+      { "id": 3, "name": "happy" }
+    ]
+  }
+}
+```
+
 When side-loading data, your serializer cannot have the `{ root: false }` option, 
 as this would lead to invalid JSON. If you do not have a root key, the `include` 
 instruction will be ignored

lib/active_model/serializer.rb

@@ -24,9 +24,21 @@ module ActiveModel
         end
       end
 
+      EMBED_IN_ROOT_OPTIONS = [
+        :include,
+        :embed_in_root,
+        :embed_in_root_key,
+        :embed_namespace
+      ].freeze
+
       def embed(type, options={})
         CONFIG.embed = type
-        CONFIG.embed_in_root = true if options[:embed_in_root] || options[:include]
+        if EMBED_IN_ROOT_OPTIONS.any? { |opt| options[opt].present? }
+          CONFIG.embed_in_root = true
+        end
+        if options[:embed_in_root_key].present?
+          CONFIG.embed_in_root_key = options[:embed_in_root_key]
+        end
         ActiveSupport::Deprecation.warn <<-WARN
 ** Notice: embed is deprecated. **
 The use of .embed method on a Serializer will be soon removed, as this should have a global scope and not a class scope.
@@ -141,8 +153,17 @@ end
       associations.each_with_object({}) do |(name, association), hash|
         if included_associations.include? name
           if association.embed_ids?
-            hash[association.key] = serialize_ids association
+            ids = serialize_ids association
+            if association.embed_namespace?
+              hash = hash[association.embed_namespace] ||= {}
+              hash[association.key] = ids
+            else
+              hash[association.key] = ids
+            end
           elsif association.embed_objects?
+            if association.embed_namespace?
+              hash = hash[association.embed_namespace] ||= {}
+            end
             hash[association.embedded_key] = serialize association
           end
         end
@@ -165,6 +186,9 @@ end
       associations.each_with_object({}) do |(name, association), hash|
         if included_associations.include? name
           if association.embed_in_root?
+            if association.embed_in_root_key?
+              hash = hash[association.embed_in_root_key] ||= {}
+            end
             association_serializer = build_serializer(association)
             hash.merge!(association_serializer.embedded_in_root_associations) {|key, oldval, newval| [newval, oldval].flatten }
 
@@ -231,4 +255,5 @@ end
     end
     alias_method :serializable_hash, :serializable_object
   end
+
 end

lib/active_model/serializer/associations.rb

@@ -18,16 +18,20 @@ module ActiveModel
         @embed_key     = options[:embed_key] || :id
         @key           = options[:key]
         @embedded_key  = options[:root] || name
+        @embed_in_root_key = options.fetch(:embed_in_root_key) { CONFIG.embed_in_root_key }
+        @embed_namespace = options.fetch(:embed_namespace) { CONFIG.embed_namespace }
 
         serializer = @options[:serializer]
         @serializer_from_options = serializer.is_a?(String) ? serializer.constantize : serializer
       end
 
       attr_reader :name, :embed_ids, :embed_objects
-      attr_accessor :embed_in_root, :embed_key, :key, :embedded_key, :root_key, :serializer_from_options, :options, :key_format
+      attr_accessor :embed_in_root, :embed_key, :key, :embedded_key, :root_key, :serializer_from_options, :options, :key_format, :embed_in_root_key, :embed_namespace
       alias embed_ids? embed_ids
       alias embed_objects? embed_objects
       alias embed_in_root? embed_in_root
+      alias embed_in_root_key? embed_in_root_key
+      alias embed_namespace? embed_namespace
 
       def embed=(embed)
         @embed_ids     = embed == :id || embed == :ids

test/unit/active_model/serializer/has_many_test.rb

@@ -168,6 +168,63 @@ module ActiveModel
           'post' => { title: 'Title 1', body: 'Body 1', comments: { my_content: ['fake'] } }
         }, @post_serializer.as_json)
       end
+
+      def test_associations_embedding_ids_including_objects_serialization_with_embed_in_root_key
+        @association.embed_in_root = true
+        @association.embed_in_root_key = :linked
+        @association.embed = :ids
+        assert_equal({
+          linked: {
+            comments: [
+              { content: 'C1' },
+              { content: 'C2' }
+            ]
+          },
+          'post' => {
+            title: 'Title 1', body: 'Body 1',
+            'comment_ids' => @post.comments.map(&:object_id)
+          }
+        }, @post_serializer.as_json)
+      end
+
+      def test_associations_embedding_ids_using_embed_namespace_including_object_serialization_with_embed_in_root_key
+        @association.embed_in_root = true
+        @association.embed_in_root_key = :linked
+        @association.embed = :ids
+        @association.embed_namespace = :links
+        @association.key = :comments
+        assert_equal({
+          linked: {
+            comments: [
+              { content: 'C1' },
+              { content: 'C2' }
+            ]
+          },
+          'post' => {
+            title: 'Title 1', body: 'Body 1',
+            links: {
+              comments: @post.comments.map(&:object_id)
+            }
+          }
+        }, @post_serializer.as_json)
+      end
+
+      def test_associations_embedding_objects_using_embed_namespace
+        @association.embed = :objects
+        @association.embed_namespace = :links
+
+        assert_equal({
+          'post' => {
+            title: 'Title 1', body: 'Body 1',
+            links: {
+              comments: [
+                { content: 'C1' },
+                { content: 'C2' }
+              ]
+            }
+          }
+        }, @post_serializer.as_json)
+      end
     end
   end
 end

test/unit/active_model/serializer/has_one_test.rb

@@ -161,6 +161,47 @@ module ActiveModel
           'user' => { name: 'Name 1', email: 'mail@server.com', profile: { name: 'fake' } }
         }, @user_serializer.as_json)
       end
+
+      def test_associations_embedding_ids_using_embed_namespace
+        @association.embed_namespace = :links
+        @association.embed = :ids
+        @association.key = :profile
+        assert_equal({
+          'user' => {
+            name: 'Name 1', email: 'mail@server.com',
+            links: {
+              profile: @user.profile.object_id
+            }
+          }
+        }, @user_serializer.as_json)
+      end
+
+      def test_asociations_embedding_objects_using_embed_namespace
+        @association.embed_namespace = :links
+        @association.embed = :objects
+        assert_equal({
+          'user' => {
+            name: 'Name 1', email: 'mail@server.com',
+            links: {
+              profile: { name: 'N1', description: 'D1' }
+            }
+          }
+        }, @user_serializer.as_json)
+      end
+
+      def test_associations_embedding_ids_using_embed_namespace_and_embed_in_root_key
+        @association.embed_in_root = true
+        @association.embed_in_root_key = :linked
+        @association.embed = :ids
+        assert_equal({
+          'user' => {
+            name: 'Name 1', email: 'mail@server.com', 'profile_id' => @user.profile.object_id
+          },
+          linked: {
+            'profiles' => [ { name: 'N1', description: 'D1' } ]
+          }
+        }, @user_serializer.as_json)
+      end
     end
   end
 end