Added hidden_attributes method for default hidden attributes.

lib/active_model/serializer.rb

@@ -15,6 +15,7 @@ class << self
       def inherited(base)
         base._root = _root
         base._attributes = (_attributes || []).dup
+        base._hidden_attributes = (_hidden_attributes || []).dup
         base._associations = (_associations || {}).dup
       end
 
@@ -60,7 +61,7 @@ def serializer_for(resource)
         end
       end
 
-      attr_accessor :_root, :_attributes, :_associations
+      attr_accessor :_root, :_attributes, :_hidden_attributes, :_associations
       alias root  _root=
       alias root= _root=
 
@@ -86,6 +87,11 @@ def has_many(*attrs)
         associate(Association::HasMany, *attrs)
       end
 
+      def hidden_attributes(*attrs)
+        @_hidden_attributes.concat attrs
+        attributes(*attrs)
+      end
+
       private
 
       def associate(klass, *attrs)
@@ -110,6 +116,7 @@ def initialize(object, options={})
       @wrap_in_array = options[:_wrap_in_array]
       @only          = Array(options[:only]) if options[:only]
       @except        = Array(options[:except]) if options[:except]
+      @expose        = Array(options[:expose]) if options[:expose]
     end
     attr_accessor :object, :scope, :root, :meta_key, :meta
 
@@ -127,6 +134,10 @@ def attributes
       end
     end
 
+    def hidden_attributes
+      self.class._hidden_attributes
+    end
+
     def associations
       associations = self.class._associations
       included_associations = filter(associations.keys)
@@ -142,6 +153,8 @@ def associations
     end
 
     def filter(keys)
+      @expose ||= []
+      hidden_attributes.each { |item| keys.delete(item) unless @expose.include?(item) }
       if @only
         keys & @only
       elsif @except

test/fixtures/poro.rb

@@ -35,6 +35,9 @@ def comments
 class Comment < Model
 end
 
+class Desk < Model
+end
+
 ###
 ## Serializers
 ###
@@ -62,3 +65,8 @@ class PostSerializer < ActiveModel::Serializer
 class CommentSerializer < ActiveModel::Serializer
   attributes :content
 end
+
+class DeskSerializer < ActiveModel::Serializer
+  attributes :drawer, :lamp
+  hidden_attributes :secret_document
+end

test/unit/active_model/serializer/filter_test.rb

@@ -5,6 +5,7 @@ class Serializer
     class FilterOptionsTest < Minitest::Test
       def setup
         @profile = Profile.new({ name: 'Name 1', description: 'Description 1', comments: 'Comments 1' })
+        @desk = Desk.new({ drawer: 'My drawer', lamp: 'My lamp', secret_document: 'Some secret document' })
       end
 
       def test_only_option
@@ -20,6 +21,20 @@ def test_except_option
           'profile' => { name: 'Name 1', description: 'Description 1' }
         }, @profile_serializer.as_json)
       end
+
+      def test_not_expose_hidden_attribute
+        desk_serializer = DeskSerializer.new(@desk)
+        assert_equal({
+          'desk' => { drawer: 'My drawer', lamp: 'My lamp' }
+        }, desk_serializer.as_json)
+      end
+
+      def test_expose_hidden_attribute
+        desk_serializer = DeskSerializer.new(@desk, expose: :secret_document)
+        assert_equal({
+          'desk' => { drawer: 'My drawer', lamp: 'My lamp', secret_document: 'Some secret document' }
+        }, desk_serializer.as_json)
+      end
     end
 
     class FilterAttributesTest < Minitest::Test