lib/alba/serializer.rb in alba-0.7.0 vs lib/alba/serializer.rb in alba-0.8.0

@@ -8,18 +8,22 @@
 
     # Instance methods
     module InstanceMethods
       def initialize(resource)
         @_opts = self.class._opts || {}
+        @_metadata = self.class._metadata || {}
+        @_metadata = @_metadata.transform_values { |block| block.call(resource._object) }
         key = case @_opts[:key]
               when true
                 resource.key
               else
                 @_opts[:key]
               end
         @hash = resource.serializable_hash(with_key: false)
         @hash = {key.to_sym => @hash} if key
+        # @hash is either Hash or Array
+        @hash.is_a?(Hash) ? @hash.merge!(@_metadata.to_h) : @hash << @_metadata
       end
 
       def serialize
         fallback = lambda do
           require 'json'
@@ -39,14 +43,23 @@
       end
     end
 
     # Class methods
     module ClassMethods
-      attr_reader :_opts
+      attr_reader :_opts, :_metadata
 
+      def inherited(subclass)
+        %w[_opts _metadata].each { |name| subclass.instance_variable_set("@#{name}", instance_variable_get("@#{name}")) }
+      end
+
       def set(key: false)
         @_opts ||= {}
         @_opts[:key] = key
+      end
+
+      def metadata(name, &block)
+        @_metadata ||= {}
+        @_metadata[name] = block
       end
     end
   end
 end