Ported serializers.

lib/action_controller/serialization.rb

@@ -0,0 +1,51 @@
+module ActionController
+  # Action Controller Serialization
+  #
+  # Overrides render :json to check if the given object implements +active_model_serializer+
+  # as a method. If so, use the returned serializer instead of calling +to_json+ in the object.
+  #
+  # This module also provides a serialization_scope method that allows you to configure the
+  # +serialization_scope+ of the serializer. Most apps will likely set the +serialization_scope+
+  # to the current user:
+  #
+  #    class ApplicationController < ActionController::Base
+  #      serialization_scope :current_user
+  #    end
+  #
+  # If you need more complex scope rules, you can simply override the serialization_scope:
+  #
+  #    class ApplicationController < ActionController::Base
+  #      private
+  #      
+  #      def serialization_scope
+  #        current_user
+  #      end
+  #    end
+  #
+  module Serialization
+    extend ActiveSupport::Concern
+
+    include ActionController::Renderers
+
+    included do
+      class_attribute :_serialization_scope
+    end
+
+    def serialization_scope
+      send(_serialization_scope)
+    end
+
+    def _render_option_json(json, options)
+      if json.respond_to?(:active_model_serializer) && (serializer = json.active_model_serializer)
+        json = serializer.new(json, serialization_scope)
+      end
+      super
+    end
+
+    module ClassMethods
+      def serialization_scope(scope)
+        self._serialization_scope = scope
+      end
+    end
+  end
+end

lib/active_model/serializer.rb

@@ -0,0 +1,253 @@
+require "active_support/core_ext/class/attribute"
+require "active_support/core_ext/string/inflections"
+require "active_support/core_ext/module/anonymous"
+require "set"
+
+module ActiveModel
+  # Active Model Array Serializer
+  #
+  # It serializes an array checking if each element that implements
+  # the +active_model_serializer+ method passing down the current scope.
+  class ArraySerializer
+    attr_reader :object, :scope
+
+    def initialize(object, scope)
+      @object, @scope = object, scope
+    end
+
+    def serializable_array
+      @object.map do |item|
+        if item.respond_to?(:active_model_serializer) && (serializer = item.active_model_serializer)
+          serializer.new(item, scope)
+        else
+          item
+        end
+      end
+    end
+
+    def as_json(*args)
+      serializable_array.as_json(*args)
+    end
+  end
+
+  # Active Model Serializer
+  #
+  # Provides a basic serializer implementation that allows you to easily
+  # control how a given object is going to be serialized. On initialization,
+  # it expects to object as arguments, a resource and a scope. For example,
+  # one may do in a controller:
+  #
+  #     PostSerializer.new(@post, current_user).to_json
+  #
+  # The object to be serialized is the +@post+ and the scope is +current_user+.
+  #
+  # We use the scope to check if a given attribute should be serialized or not.
+  # For example, some attributes maybe only be returned if +current_user+ is the
+  # author of the post:
+  #
+  #     class PostSerializer < ActiveModel::Serializer
+  #       attributes :title, :body
+  #       has_many :comments
+  #     
+  #       private
+  #
+  #       def attributes
+  #         hash = super
+  #         hash.merge!(:email => post.email) if author?
+  #         hash
+  #       end
+  #     
+  #       def author?
+  #         post.author == scope
+  #       end
+  #     end
+  #
+  class Serializer
+    module Associations #:nodoc:
+      class Config < Struct.new(:name, :options) #:nodoc:
+        def serializer
+          options[:serializer]
+        end
+      end
+
+      class HasMany < Config #:nodoc:
+        def serialize(collection, scope)
+          collection.map do |item|
+            serializer.new(item, scope).serializable_hash
+          end
+        end
+
+        def serialize_ids(collection, scope)
+          # use named scopes if they are present
+          # return collection.ids if collection.respond_to?(:ids)
+
+          collection.map do |item|
+            item.read_attribute_for_serialization(:id)
+          end
+        end
+      end
+
+      class HasOne < Config #:nodoc:
+        def serialize(object, scope)
+          object && serializer.new(object, scope).serializable_hash
+        end
+
+        def serialize_ids(object, scope)
+          object && object.read_attribute_for_serialization(:id)
+        end
+      end
+    end
+
+    class_attribute :_attributes
+    self._attributes = Set.new
+
+    class_attribute :_associations
+    self._associations = []
+
+    class_attribute :_root
+    class_attribute :_embed
+    self._embed = :objects
+    class_attribute :_root_embed
+
+    class << self
+      # Define attributes to be used in the serialization.
+      def attributes(*attrs)
+        self._attributes += attrs
+      end
+
+      def associate(klass, attrs) #:nodoc:
+        options = attrs.extract_options!
+        self._associations += attrs.map do |attr|
+          unless method_defined?(attr)
+            class_eval "def #{attr}() object.#{attr} end", __FILE__, __LINE__
+          end
+
+          options[:serializer] ||= const_get("#{attr.to_s.camelize}Serializer")
+          klass.new(attr, options)
+        end
+      end
+
+      # Defines an association in the object should be rendered.
+      #
+      # The serializer object should implement the association name
+      # as a method which should return an array when invoked. If a method
+      # with the association name does not exist, the association name is
+      # dispatched to the serialized object.
+      def has_many(*attrs)
+        associate(Associations::HasMany, attrs)
+      end
+
+      # Defines an association in the object should be rendered.
+      #
+      # The serializer object should implement the association name
+      # as a method which should return an object when invoked. If a method
+      # with the association name does not exist, the association name is
+      # dispatched to the serialized object.
+      def has_one(*attrs)
+        associate(Associations::HasOne, attrs)
+      end
+
+      # Define how associations should be embedded.
+      #
+      #   embed :objects               # Embed associations as full objects
+      #   embed :ids                   # Embed only the association ids
+      #   embed :ids, :include => true # Embed the association ids and include objects in the root
+      #
+      def embed(type, options={})
+        self._embed = type
+        self._root_embed = true if options[:include]
+      end
+
+      # Defines the root used on serialization. If false, disables the root.
+      def root(name)
+        self._root = name
+      end
+
+      def inherited(klass) #:nodoc:
+        return if klass.anonymous?
+
+        name = klass.name.demodulize.underscore.sub(/_serializer$/, '')
+
+        klass.class_eval do
+          alias_method name.to_sym, :object
+          root name.to_sym unless self._root == false
+        end
+      end
+    end
+
+    attr_reader :object, :scope
+
+    def initialize(object, scope)
+      @object, @scope = object, scope
+    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
+        hash
+      else
+        serializable_hash
+      end
+    end
+
+    # Returns a hash representation of the serializable
+    # object without the root.
+    def serializable_hash
+      if _embed == :ids
+        attributes.merge(association_ids)
+      elsif _embed == :objects
+        attributes.merge(associations)
+      else
+        attributes
+      end
+    end
+
+    # Returns a hash representation of the serializable
+    # object associations.
+    def associations
+      hash = {}
+
+      _associations.each do |association|
+        associated_object = send(association.name)
+        hash[association.name] = association.serialize(associated_object, scope)
+      end
+
+      hash
+    end
+
+    # Returns a hash representation of the serializable
+    # object associations ids.
+    def association_ids
+      hash = {}
+
+      _associations.each do |association|
+        associated_object = send(association.name)
+        hash[association.name] = association.serialize_ids(associated_object, scope)
+      end
+
+      hash
+    end
+
+    # Returns a hash representation of the serializable
+    # object attributes.
+    def attributes
+      hash = {}
+
+      _attributes.each do |name|
+        hash[name] = @object.read_attribute_for_serialization(name)
+      end
+
+      hash
+    end
+  end
+end
+
+class Array
+  # Array uses ActiveModel::ArraySerializer.
+  def active_model_serializer
+    ActiveModel::ArraySerializer
+  end
+end

lib/active_model_serializers.rb

@@ -0,0 +1,28 @@
+require "active_model"
+require "active_model/serializer"
+
+ActiveModel::Serialization.class_eval do
+  extend ActiveSupport::Concern
+
+  module ClassMethods #:nodoc:
+    def active_model_serializer
+      return @active_model_serializer if defined?(@active_model_serializer)
+      @active_model_serializer = "#{self.name}Serializer".safe_constantize
+    end
+  end
+
+  # Returns a model serializer for this object considering its namespace.
+  def active_model_serializer
+    self.class.active_model_serializer
+  end
+end
+
+require "action_controller"
+
+module ActionController
+  autoload :Serialization, "action_controller/serialization"
+end
+
+ActiveSupport.on_load(:action_controller) do
+  include ::ActionController::Serialization
+end

lib/rails/generators/rails/serializer/USAGE

@@ -0,0 +1,9 @@
+Description:
+    Generates a serializer for the given resource with tests.
+
+Example:
+    `rails generate serializer Account name created_at`
+
+    For TestUnit it creates:
+        Serializer:  app/serializers/account_serializer.rb
+        TestUnit:    test/unit/account_serializer_test.rb

lib/rails/generators/rails/serializer/serializer_generator.rb

@@ -0,0 +1,39 @@
+module Rails
+  module Generators
+    class SerializerGenerator < NamedBase
+      check_class_collision :suffix => "Serializer"
+
+      argument :attributes, :type => :array, :default => [], :banner => "field:type field:type"
+
+      class_option :parent, :type => :string, :desc => "The parent class for the generated serializer"
+
+      def create_serializer_file
+        template 'serializer.rb', File.join('app/serializers', class_path, "#{file_name}_serializer.rb")
+      end
+
+      hook_for :test_framework
+
+      private
+
+      def attributes_names
+        attributes.select { |attr| !attr.reference? }.map { |a| a.name.to_sym }
+      end
+
+      def association_names
+        attributes.select { |attr| attr.reference? }.map { |a| a.name.to_sym }
+      end
+
+      def parent_class_name
+        if options[:parent]
+          options[:parent]
+        elsif (n = Rails::Generators.namespace) && n.const_defined?(:ApplicationSerializer)
+          "ApplicationSerializer"
+        elsif Object.const_defined?(:ApplicationSerializer)
+          "ApplicationSerializer"
+        else
+          "ActiveModel::Serializer"
+        end
+      end
+    end
+  end
+end

lib/rails/generators/rails/serializer/templates/serializer.rb

@@ -0,0 +1,9 @@
+<% module_namespacing  do -%>
+class <%= class_name %>Serializer < <%= parent_class_name %>
+<% if attributes.any? -%>  attributes <%= attributes_names.map(&:inspect).join(", ") %>
+<% end -%>
+<% association_names.each  do |attribute| -%>
+  has_one :<%= attribute %>
+<% end  -%>
+end
+<% end -%>

lib/rails/generators/test_unit/serializer/serializer_generator.rb

@@ -0,0 +1,13 @@
+require 'rails/generators/test_unit'
+
+module TestUnit
+  module Generators
+    class SerializerGenerator < Base
+      check_class_collision :suffix => "SerializerTest"
+
+      def create_test_files
+        template 'unit_test.rb',  File.join('test/unit', class_path, "#{file_name}_serializer_test.rb")
+      end
+    end
+  end
+end

lib/rails/generators/test_unit/serializer/templates/unit_test.rb

@@ -0,0 +1,9 @@
+require 'test_helper'
+
+<% module_namespacing  do -%>
+class <%= class_name %>SerializerTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end
+<% end  -%>