Added has_one and has_many

1 files changed, 47 insertions, 9 deletions

diff --git a/activemodel/lib/active_model/serializer.rb b/activemodel/lib/active_model/serializer.rb
index a2035ae2cb..dc5e2aadb3 100644
--- a/activemodel/lib/active_model/serializer.rb
+++ b/activemodel/lib/active_model/serializer.rb
@@ -7,20 +7,41 @@ module ActiveModel
     class_attribute :_attributes
     self._attributes = Set.new
 
-    def self.attributes(*attrs)
-      self._attributes += attrs
-    end
+    class_attribute :_associations
+    self._associations = {}
 
-    attr_reader :object, :scope
+    class << self
+      def attributes(*attrs)
+        self._attributes += attrs
+      end
+
+      def has_many(*attrs)
+        options = attrs.extract_options!
+        options[:has_many] = true
+        hash = {}
+        attrs.each { |attr| hash[attr] = options }
+        self._associations = _associations.merge(hash)
+      end
+
+      def has_one(*attrs)
+        options = attrs.extract_options!
+        options[:has_one] = true
+        hash = {}
+        attrs.each { |attr| hash[attr] = options }
+        self._associations = _associations.merge(hash)
+      end
 
-    def self.inherited(klass)
-      name = klass.name.demodulize.underscore.sub(/_serializer$/, '')
+      def inherited(klass)
+        name = klass.name.demodulize.underscore.sub(/_serializer$/, '')
 
-      klass.class_eval do
-        alias_method name.to_sym, :object
+        klass.class_eval do
+          alias_method name.to_sym, :object
+        end
       end
     end
 
+    attr_reader :object, :scope
+
     def initialize(object, scope)
       @object, @scope = object, scope
     end
@@ -30,7 +51,24 @@ module ActiveModel
     end
 
     def serializable_hash
-      attributes
+      hash = attributes
+
+      _associations.each do |association, options|
+        associated_object = object.send(association)
+        serializer = options[:serializer]
+
+        if options[:has_many]
+          serialized_array = associated_object.map do |item|
+            serializer.new(item, scope).serializable_hash
+          end
+
+          hash[association] = serialized_array
+        elsif options[:has_one]
+          hash[association] = serializer.new(associated_object, scope).serializable_hash
+        end
+      end
+
+      hash
     end
 
     def attributes