Generalize merging embedded attributes

app/serializers/announcement_serializer.rb

@@ -5,10 +5,7 @@ class AnnouncementSerializer
   all_attributes
   can_sort_by :created_at
   can_filter_by :section
+  embed_attributes_from :project
   self.default_sort = 'created_at'
   self.eager_loads = [:project]
-
-  def custom_attributes
-    super.merge attributes_from :project
-  end
 end

app/serializers/board_serializer.rb

@@ -6,10 +6,7 @@ class BoardSerializer
   can_include :discussions, :parent, :sub_boards
   can_filter_by :subject_default
   can_sort_by :created_at
+  embed_attributes_from :project
   self.default_sort = 'created_at'
   self.eager_loads = [:project]
-
-  def custom_attributes
-    super.merge attributes_from :project
-  end
 end

app/serializers/comment_serializer.rb

@@ -7,15 +7,12 @@ class CommentSerializer
   can_include :discussion
   can_sort_by :created_at
   can_filter_by :user_id, :focus_id, :focus_type
+  embed_attributes_from :discussion, :board, :project
   self.default_sort = 'created_at'
   self.eager_loads = [:user, :focus, :discussion, :board, :project]
 
   def custom_attributes
-    super
-      .merge(attributes_from(:discussion))
-      .merge(attributes_from(:board))
-      .merge(attributes_from(:project))
-      .merge focus: focus, user_display_name: model.user.display_name
+    super.merge focus: focus, user_display_name: model.user.display_name
   end
 
   def focus

app/serializers/concerns/embedded_attributes.rb

@@ -1,6 +1,18 @@
 module EmbeddedAttributes
   extend ActiveSupport::Concern
 
+  included do
+    class_attribute :_embedded_attributes
+    self._embedded_attributes = []
+  end
+
+  module ClassMethods
+    def embed_attributes_from(*list)
+      self._embedded_attributes += list.map(&:to_sym)
+      self._embedded_attributes.uniq!
+    end
+  end
+
   def discussion_attributes
     %w(comments_count subject_default title updated_at users_count)
   end
@@ -13,6 +25,14 @@ def project_attributes
     %w(slug)
   end
 
+  def custom_attributes
+    super.tap do |custom_attrs|
+      self._embedded_attributes.each do |relation|
+        custom_attrs.merge! attributes_from relation
+      end
+    end
+  end
+
   def attributes_from(relation)
     { }.tap do |attrs|
       record_attributes = model.send(relation).attributes rescue { }

app/serializers/discussion_serializer.rb

@@ -7,13 +7,11 @@ class DiscussionSerializer
   can_include :comments, :board, :user
   can_filter_by :title, :subject_default, :sticky
   can_sort_by :updated_at, :sticky, :sticky_position
+  embed_attributes_from :project, :board
   self.default_sort = '-sticky,sticky_position,-updated_at'
   self.eager_loads = [:user, :board, :project]
 
   def custom_attributes
-    super
-      .merge(attributes_from(:project))
-      .merge(attributes_from(:board))
-      .merge user_display_name: model.user.display_name
+    super.merge user_display_name: model.user.display_name
   end
 end

app/serializers/notification_serializer.rb

@@ -6,10 +6,7 @@ class NotificationSerializer
   can_sort_by :created_at
   can_filter_by :section, :delivered
   can_include :subscription
+  embed_attributes_from :project
   self.default_sort = 'created_at'
   self.eager_loads = [:project]
-
-  def custom_attributes
-    super.merge attributes_from :project
-  end
 end

app/serializers/tag_serializer.rb

@@ -2,9 +2,6 @@ class TagSerializer
   include TalkSerializer
   include EmbeddedAttributes
   all_attributes
+  embed_attributes_from :project
   self.eager_loads = [:project]
-
-  def custom_attributes
-    super.merge attributes_from :project
-  end
 end