Improve serializers:

* Many nested levels of associations can now insert
  their information alongside the original when
  embed :ids, :include => true is true
* Add support for passing options to serializers
* Fix Array serializers so they don't try to insert
  roots for each child object and so they can be
  provided a root.
* TODO: Array serializers should require a root
* TODO: Make merging associations at the root more
  efficient if possible

lib/action_controller/serialization.rb

@@ -38,7 +38,7 @@ module ActionController
 
     def _render_option_json(json, options)
       if json.respond_to?(:active_model_serializer) && (serializer = json.active_model_serializer)
-        json = serializer.new(json, serialization_scope)
+        json = serializer.new(json, serialization_scope, options)
       end
       super
     end

lib/active_model/serializer.rb

@@ -11,14 +11,15 @@ module ActiveModel
   class ArraySerializer
     attr_reader :object, :scope
 
-    def initialize(object, scope)
-      @object, @scope = object, scope
+    def initialize(object, scope, options={})
+      @object, @scope, @options = object, scope, options
+      @hash = options[:hash]
     end
 
     def serializable_array
       @object.map do |item|
         if item.respond_to?(:active_model_serializer) && (serializer = item.active_model_serializer)
-          serializer.new(item, scope)
+          serializer.new(item, scope, :hash => @hash)
         else
           item
         end
@@ -26,7 +27,14 @@ module ActiveModel
     end
 
     def as_json(*args)
-      serializable_array.as_json(*args)
+      @hash = {}
+      array = serializable_array.as_json(*args)
+
+      if root = @options[:root]
+        @hash.merge!(root => array)
+      else
+        array
+      end
     end
   end
 
@@ -75,9 +83,9 @@ module ActiveModel
       end
 
       class HasMany < Config #:nodoc:
-        def serialize(collection, scope)
+        def serialize(collection, scope, options)
           collection.map do |item|
-            serializer.new(item, scope).serializable_hash
+            serializer.new(item, scope, options).serializable_hash
           end
         end
 
@@ -92,8 +100,8 @@ module ActiveModel
       end
 
       class HasOne < Config #:nodoc:
-        def serialize(object, scope)
-          object && serializer.new(object, scope).serializable_hash
+        def serialize(object, scope, options)
+          object && serializer.new(object, scope, options).serializable_hash
         end
 
         def serialize_ids(object, scope)
@@ -245,19 +253,20 @@ module ActiveModel
 
     attr_reader :object, :scope
 
-    def initialize(object, scope)
-      @object, @scope = object, scope
+    def initialize(object, scope, options={})
+      @object, @scope, @options = object, scope, options
+      @hash = options[:hash]
     end
 
     # Returns a json representation of the serializable
     # object including the root.
     def as_json(*)
-      if _root
-        hash = { _root => serializable_hash }
-        hash.merge!(associations) if _root_embed
+      if root = @options[:root] || _root
+        @hash = hash = {}
+        hash.merge!(root => serializable_hash)
         hash
       else
-        serializable_hash
+        @hash = serializable_hash
       end
     end
 
@@ -265,6 +274,7 @@ module ActiveModel
     # object without the root.
     def serializable_hash
       if _embed == :ids
+        merge_associations(@hash, associations) if _root_embed
         attributes.merge(association_ids)
       elsif _embed == :objects
         attributes.merge(associations)
@@ -273,6 +283,16 @@ module ActiveModel
       end
     end
 
+    def merge_associations(hash, associations)
+      associations.each do |key, value|
+        if hash[key]
+          hash[key] |= value
+        elsif value
+          hash[key] = value
+        end
+      end
+    end
+
     # Returns a hash representation of the serializable
     # object associations.
     def associations
@@ -280,7 +300,7 @@ module ActiveModel
 
       _associations.each do |association|
         associated_object = send(association.name)
-        hash[association.key] = association.serialize(associated_object, scope)
+        hash[association.key] = association.serialize(associated_object, scope, :hash => @hash)
       end
 
       hash

test/serialization_test.rb

@@ -15,12 +15,14 @@ class RenderJsonTest < ActionController::TestCase
   end
 
   class JsonSerializer
-    def initialize(object, scope)
-      @object, @scope = object, scope
+    def initialize(object, scope, options={})
+      @object, @scope, @options = object, scope, options
     end
 
     def as_json(*)
-      { :object => @object.as_json, :scope => @scope.as_json }
+      hash = { :object => @object.as_json, :scope => @scope.as_json }
+      hash.merge!(:options => true) if @options[:options]
+      hash
     end
   end
 
@@ -89,6 +91,11 @@ class RenderJsonTest < ActionController::TestCase
       render :json => JsonSerializable.new
     end
 
+    def render_json_with_serializer_and_options
+      @current_user = Struct.new(:as_json).new(:current_user => true)
+      render :json => JsonSerializable.new, :options => true
+    end
+
     def render_json_with_serializer_api_but_without_serializer
       @current_user = Struct.new(:as_json).new(:current_user => true)
       render :json => JsonSerializable.new(true)
@@ -165,6 +172,13 @@ class RenderJsonTest < ActionController::TestCase
     assert_match '"object":{"serializable_object":true}', @response.body
   end
 
+  def test_render_json_with_serializer_and_options
+    get :render_json_with_serializer_and_options
+    assert_match '"scope":{"current_user":true}', @response.body
+    assert_match '"object":{"serializable_object":true}', @response.body
+    assert_match '"options":true', @response.body
+  end
+
   def test_render_json_with_serializer_api_but_without_serializer
     get :render_json_with_serializer_api_but_without_serializer
     assert_match '{"serializable_object":true}', @response.body

test/serializer_test.rb

@@ -70,7 +70,7 @@ class SerializerTest < ActiveModel::TestCase
   end
 
   class CommentSerializer
-    def initialize(comment, scope)
+    def initialize(comment, scope, options={})
       @comment, @scope = comment, scope
     end
 
@@ -680,4 +680,133 @@ class SerializerTest < ActiveModel::TestCase
       }
     }, hash.as_json)
   end
+
+  def test_root_provided_in_options
+    author_serializer = Class.new(ActiveModel::Serializer) do
+      attributes :id, :name
+    end
+
+    serializer_class = Class.new(ActiveModel::Serializer) do
+      root :post
+
+      attributes :title, :body
+      has_one :author, :serializer => author_serializer
+    end
+
+    post_class = Class.new(Model) do
+      attr_accessor :author
+    end
+
+    author_class = Class.new(Model)
+
+    post = post_class.new(:title => "New Post", :body => "It's a new post!")
+    author = author_class.new(:id => 5, :name => "Tom Dale")
+    post.author = author
+
+    hash = serializer_class.new(post, nil, :root => :blog_post)
+
+    assert_equal({
+      :blog_post => {
+        :title => "New Post",
+        :body => "It's a new post!",
+        :author => { :id => 5, :name => "Tom Dale" }
+      }
+    }, hash.as_json)
+  end
+
+  def test_serializer_has_access_to_root_object
+    hash_object = nil
+
+    author_serializer = Class.new(ActiveModel::Serializer) do
+      attributes :id, :name
+
+      define_method :serializable_hash do
+        hash_object = @hash
+        super()
+      end
+    end
+
+    serializer_class = Class.new(ActiveModel::Serializer) do
+      root :post
+
+      attributes :title, :body
+      has_one :author, :serializer => author_serializer
+    end
+
+    post_class = Class.new(Model) do
+      attr_accessor :author
+    end
+
+    author_class = Class.new(Model)
+
+    post = post_class.new(:title => "New Post", :body => "It's a new post!")
+    author = author_class.new(:id => 5, :name => "Tom Dale")
+    post.author = author
+
+    expected = serializer_class.new(post, nil).as_json
+    assert_equal expected, hash_object
+  end
+
+  # the point of this test is to illustrate that deeply nested serializers
+  # still side-load at the root.
+  def test_embed_with_include_inserts_at_root
+    tag_serializer = Class.new(ActiveModel::Serializer) do
+      attributes :id, :name
+    end
+
+    comment_serializer = Class.new(ActiveModel::Serializer) do
+      embed :ids, :include => true
+      attributes :id, :body
+      has_many :tags, :serializer => tag_serializer
+    end
+
+    post_serializer = Class.new(ActiveModel::Serializer) do
+      embed :ids, :include => true
+      attributes :id, :title, :body
+      has_many :comments, :serializer => comment_serializer
+    end
+
+    post_class = Class.new(Model) do
+      attr_accessor :comments
+
+      define_method :active_model_serializer do
+        post_serializer
+      end
+    end
+
+    comment_class = Class.new(Model) do
+      attr_accessor :tags
+    end
+
+    tag_class = Class.new(Model)
+
+    post = post_class.new(:title => "New Post", :body => "NEW POST", :id => 1)
+    comment1 = comment_class.new(:body => "EWOT", :id => 1)
+    comment2 = comment_class.new(:body => "YARLY", :id => 2)
+    tag1 = tag_class.new(:name => "lolcat", :id => 1)
+    tag2 = tag_class.new(:name => "nyancat", :id => 2)
+    tag3 = tag_class.new(:name => "violetcat", :id => 3)
+
+    post.comments = [comment1, comment2]
+    comment1.tags = [tag1, tag3]
+    comment2.tags = [tag1, tag2]
+
+    actual = ActiveModel::ArraySerializer.new([post], nil, :root => :posts).as_json
+    assert_equal({
+      :posts => [
+        { :title => "New Post", :body => "NEW POST", :id => 1, :comments => [1,2] }
+      ],
+
+      :comments => [
+        { :body => "EWOT", :id => 1, :tags => [1,3] },
+        { :body => "YARLY", :id => 2, :tags => [1,2] }
+      ],
+
+      :tags => [
+        { :name => "lolcat", :id => 1 },
+        { :name => "violetcat", :id => 3 },
+        { :name => "nyancat", :id => 2 }
+      ]
+    }, actual)
+  end
 end

test/test_helper.rb

@@ -1,7 +1,5 @@
 require "rubygems"
-require "bundler"
-
-Bundler.setup
+require "bundler/setup"
 
 require "active_model_serializers"
 require "active_support/json"