Slightly modified how extra serialized properties should work

lib/dm-serializer.rb

@@ -27,19 +27,20 @@ def to_json(options = {})
       excluded_properties = Array(options[:exclude])
       exclude_read_only   = options[:without_read_only_attributes] || false
 
-      propset = self.class.properties(repository.name).dup
-      if self.class.respond_to?(:serialize_properties)
-        self.class.serialize_properties(repository.name).each {|p| propset << Property.new(self.class, p, String) }
-      end
-
-      propset = propset.reject do |p|
+      propset = self.class.properties.reject do |p|
         next if only_properties.include? p.name
         excluded_properties.include?(p.name) || !(only_properties.empty? || only_properties.include?(p.name))
       end
 
       fields += propset.map do |property|
         "#{property.name.to_json}: #{send(property.getter).to_json}"
       end
+
+      if self.respond_to?(:serialize_properties)
+        self.serialize_properties.each do |k,v|
+          fields << "#{k.to_json}: #{v.to_json}"
+        end
+      end
 
       if self.class.respond_to?(:read_only_attributes) && exclude_read_only
         self.class.read_only_attributes.each do |property|

spec/fixtures/cow.rb

@@ -6,15 +6,7 @@ class Cow
   property :name,      String
   property :breed,     String
 
-  def self.serialize_properties(*args)
-    [:extra, :another]
-  end
-
-  def extra
-    "Extra"
-  end
-
-  def another
-    42
+  def serialize_properties
+    {:extra => "Extra", :another => 42}
   end
 end