use RelatedEntity as normal nested entity, but don't add it to xml

lib/diaspora_federation/entities/related_entity.rb

@@ -23,6 +23,11 @@ module DiasporaFederation
       #   if the entity also have a parent (Comment or Like), +nil+ if it has no parent
       #   @return [RelatedEntity] parent entity
       entity :parent, Entities::RelatedEntity, default: nil
+
+      # never add {RelatedEntity} to xml
+      def to_xml
+        nil
+      end
     end
   end
 end

lib/diaspora_federation/entities/relayable.rb

@@ -10,10 +10,6 @@ module DiasporaFederation
       # digest instance used for signing
       DIGEST = OpenSSL::Digest::SHA256.new
 
-      # parent entity
-      # @return [RelatedEntity] parent entity
-      attr_reader :parent
-
       # order from the parsed xml for signature
       # @return [Array] order from xml
       attr_reader :xml_order
@@ -49,20 +45,24 @@ module DiasporaFederation
       #   This signature is required only when federation from upstream (parent) post author to
       #   downstream subscribers. This is the case when the parent author has to resend a relayable
       #   received from one of his subscribers to all others.
-      #
       #   @return [String] parent author signature
       #
-      # @param [Entity] entity the entity in which it is included
-      def self.included(entity)
-        entity.class_eval do
+      # @!attribute [r] parent
+      #   meta information about the parent object
+      #   @return [RelatedEntity] parent entity
+      #
+      # @param [Entity] klass the entity in which it is included
+      def self.included(klass)
+        klass.class_eval do
           property :author, xml_name: :diaspora_handle
           property :guid
           property :parent_guid
           property :author_signature, default: nil
           property :parent_author_signature, default: nil
+          entity :parent, Entities::RelatedEntity
         end
 
-        entity.extend ParseXML
+        klass.extend ParseXML
       end
 
       # Initializes a new relayable Entity with order and additional xml elements
@@ -72,7 +72,6 @@ module DiasporaFederation
       # @param [Hash] additional_xml_elements additional xml elements
       # @see DiasporaFederation::Entity#initialize
       def initialize(data, xml_order=nil, additional_xml_elements={})
-        @parent = data[:parent] if data
         @xml_order = xml_order
         @additional_xml_elements = additional_xml_elements
 

lib/diaspora_federation/entities/relayable_retraction.rb

@@ -53,18 +53,10 @@ module DiasporaFederation
       #   @return [String] target author signature
       property :target_author_signature, default: nil
 
-      # target entity
-      # @return [RelatedEntity] target entity
-      attr_reader :target
-
-      # Initializes a new relayable retraction entity
-      #
-      # @param [Hash] data entity data
-      # @see DiasporaFederation::Entity#initialize
-      def initialize(data)
-        @target = data[:target] if data
-        super(data)
-      end
+      # @!attribute [r] target
+      #   target entity
+      #   @return [RelatedEntity] target entity
+      entity :target, Entities::RelatedEntity
 
       # use only {Retraction} for receive
       # @return [Retraction] instance as normal retraction

lib/diaspora_federation/entities/retraction.rb

@@ -20,18 +20,10 @@ module DiasporaFederation
       #   @return [String] target type
       property :target_type, xml_name: :type
 
-      # target entity
-      # @return [RelatedEntity] target entity
-      attr_reader :target
-
-      # Initializes a new retraction entity
-      #
-      # @param [Hash] data entity data
-      # @see DiasporaFederation::Entity#initialize
-      def initialize(data)
-        @target = data[:target] if data
-        super(data)
-      end
+      # @!attribute [r] target
+      #   target entity
+      #   @return [RelatedEntity] target entity
+      entity :target, Entities::RelatedEntity
 
       def sender_valid?(sender)
         case target_type

lib/diaspora_federation/entities/signed_retraction.rb

@@ -30,18 +30,10 @@ module DiasporaFederation
       #   @return [String] author signature
       property :target_author_signature, default: nil
 
-      # target entity
-      # @return [RelatedEntity] target entity
-      attr_reader :target
-
-      # Initializes a new signed retraction entity
-      #
-      # @param [Hash] data entity data
-      # @see DiasporaFederation::Entity#initialize
-      def initialize(data)
-        @target = data[:target] if data
-        super(data)
-      end
+      # @!attribute [r] target
+      #   target entity
+      #   @return [RelatedEntity] target entity
+      entity :target, Entities::RelatedEntity
 
       # use only {Retraction} for receive
       # @return [Retraction] instance as normal retraction

lib/diaspora_federation/entity.rb

@@ -225,7 +225,8 @@ module DiasporaFederation
       else
         # call #to_xml for each item and append to root
         [*value].compact.each do |item|
-          root_element << item.to_xml
+          child = item.to_xml
+          root_element << child if child
         end
       end
     end

spec/entities.rb

@@ -26,6 +26,11 @@ module DiasporaFederation
       property :qwer, xml_name: :asdf
     end
 
+    class TestEntityWithRelatedEntity < DiasporaFederation::Entity
+      property :test
+      entity :parent, RelatedEntity
+    end
+
     class Entity < DiasporaFederation::Entity
       property :test
     end

spec/lib/diaspora_federation/entities/comment_spec.rb

@@ -21,7 +21,7 @@ XML
     }
     let(:string) { "Comment:#{data[:guid]}:#{parent.guid}" }
 
-    it_behaves_like "an Entity subclass", [:parent]
+    it_behaves_like "an Entity subclass"
 
     it_behaves_like "an XML Entity", [:created_at]
 

spec/lib/diaspora_federation/entities/like_spec.rb

@@ -27,7 +27,7 @@ XML
     }
     let(:string) { "Like:#{data[:guid]}:Post:#{parent.guid}" }
 
-    it_behaves_like "an Entity subclass", [:parent]
+    it_behaves_like "an Entity subclass"
 
     it_behaves_like "an XML Entity"
 

spec/lib/diaspora_federation/entities/message_spec.rb

@@ -23,7 +23,7 @@ XML
     }
     let(:string) { "Message:#{data[:guid]}:#{parent.guid}" }
 
-    it_behaves_like "an Entity subclass", [:parent]
+    it_behaves_like "an Entity subclass"
 
     it_behaves_like "an XML Entity"
 

spec/lib/diaspora_federation/entities/participation_spec.rb

@@ -26,7 +26,7 @@ XML
     }
     let(:string) { "Participation:#{data[:guid]}:Post:#{parent.guid}" }
 
-    it_behaves_like "an Entity subclass", [:parent]
+    it_behaves_like "an Entity subclass"
 
     it_behaves_like "an XML Entity"
 

spec/lib/diaspora_federation/entities/poll_participation_spec.rb

@@ -25,7 +25,7 @@ XML
     }
     let(:string) { "PollParticipation:#{data[:guid]}:#{parent.guid}" }
 
-    it_behaves_like "an Entity subclass", [:parent]
+    it_behaves_like "an Entity subclass"
 
     it_behaves_like "an XML Entity"
 

spec/lib/diaspora_federation/entities/related_entity_spec.rb

@@ -4,5 +4,11 @@ module DiasporaFederation
     let(:string) { "RelatedEntity" }
 
     it_behaves_like "an Entity subclass"
+
+    describe "#to_xml" do
+      it "returns nil" do
+        expect(described_class.new(data).to_xml).to be_nil
+      end
+    end
   end
 end

spec/lib/diaspora_federation/entities/relayable_retraction_spec.rb

@@ -34,9 +34,9 @@ XML
     }
     let(:string) { "RelayableRetraction:#{data[:target_type]}:#{data[:target_guid]}" }
 
-    it_behaves_like "an Entity subclass", [:target]
+    it_behaves_like "an Entity subclass"
 
-    it_behaves_like "an XML Entity", %i(parent_author_signature target_author_signature)
+    it_behaves_like "an XML Entity", %i(parent_author_signature target_author_signature target)
 
     it_behaves_like "a retraction"
 

spec/lib/diaspora_federation/entities/retraction_spec.rb

@@ -22,7 +22,7 @@ XML
     }
     let(:string) { "Retraction:#{data[:target_type]}:#{data[:target_guid]}" }
 
-    it_behaves_like "an Entity subclass", [:target]
+    it_behaves_like "an Entity subclass"
 
     it_behaves_like "an XML Entity"
 

spec/lib/diaspora_federation/entities/signed_retraction_spec.rb

@@ -24,7 +24,7 @@ XML
     }
     let(:string) { "SignedRetraction:#{data[:target_type]}:#{data[:target_guid]}" }
 
-    it_behaves_like "an Entity subclass", [:target]
+    it_behaves_like "an Entity subclass"
 
     it_behaves_like "an XML Entity", [:target_author_signature]
 

spec/lib/diaspora_federation/entity_spec.rb

@@ -282,6 +282,13 @@ XML
         expect(xml.xpath("other_entity")).to have_exactly(2).items
       end
 
+      it "is not added to xml if #to_xml returns nil" do
+        entity = Entities::TestEntityWithRelatedEntity.new(test: "test", parent: FactoryGirl.build(:related_entity))
+        xml = entity.to_xml
+        expect(xml.children).to have_exactly(1).items
+        xml.children.first.name = "test"
+      end
+
       it "instantiates nested entities if provided as hash" do
         entity = Entities::TestNestedEntity.new(nested_hash)
 

spec/support/shared_entity_specs.rb

@@ -1,10 +1,10 @@
-shared_examples "an Entity subclass" do |ignored_props=[]|
+shared_examples "an Entity subclass" do
   it "should be an Entity" do
     expect(described_class).to be < DiasporaFederation::Entity
   end
 
   it "has its properties set" do
-    expect(described_class.class_props.keys).to include(*(data.keys - ignored_props))
+    expect(described_class.class_props.keys).to include(*data.keys)
   end
 
   context "behaviour" do
@@ -26,7 +26,7 @@ shared_examples "an Entity subclass" do |ignored_props=[]|
 
     describe "#to_h" do
       it "should return a hash with nested data" do
-        expected_data = Hash[data.reject {|key, _| ignored_props.include?(key) }.map {|key, value|
+        expected_data = Hash[data.map {|key, value|
           if [String, TrueClass, FalseClass, Fixnum, Time, NilClass].include?(value.class)
             [key, value]
           elsif value.instance_of?(Array)
@@ -76,7 +76,7 @@ shared_examples "an XML Entity" do |ignored_props=[]|
     if value.nil?
       expect(parsed_value).to be_nil
     elsif type == String
-      expect(parsed_value).to eq(value.to_s)
+      expect(parsed_value.to_s).to eq(value.to_s)
     elsif type.instance_of?(Array)
       value.each_with_index {|entity, index| check_entity(entity, parsed_value[index]) }
     elsif type.ancestors.include?(DiasporaFederation::Entity)