Initial implementation of ActiveModel::Serializer

2 files changed, 47 insertions, 0 deletions

diff --git a/activemodel/lib/active_model.rb b/activemodel/lib/active_model.rb
index d0e2a6f39c..28765b00bb 100644
--- a/activemodel/lib/active_model.rb
+++ b/activemodel/lib/active_model.rb
@@ -43,6 +43,7 @@ module ActiveModel
   autoload :Observer, 'active_model/observing'
   autoload :Observing
   autoload :SecurePassword
+  autoload :Serializer
   autoload :Serialization
   autoload :TestCase
   autoload :Translation
diff --git a/activemodel/lib/active_model/serializer.rb b/activemodel/lib/active_model/serializer.rb
new file mode 100644
index 0000000000..2eca3ebc5e
--- /dev/null
+++ b/activemodel/lib/active_model/serializer.rb
@@ -0,0 +1,46 @@
+require "active_support/core_ext/class/attribute"
+require "active_support/core_ext/string/inflections"
+require "set"
+
+module ActiveModel
+  class Serializer
+    class_attribute :_attributes
+    self._attributes = Set.new
+
+    def self.attributes(*attrs)
+      self._attributes += attrs
+    end
+
+    attr_reader :object, :scope
+
+    def self.inherited(klass)
+      name = klass.name.demodulize.underscore.sub(/_serializer$/, '')
+
+      klass.class_eval do
+        alias_method name.to_sym, :object
+      end
+    end
+
+    def initialize(object, scope)
+      @object, @scope = object, scope
+    end
+
+    def as_json(*)
+      serializable_hash
+    end
+
+    def serializable_hash(*)
+      attributes
+    end
+
+    def attributes
+      hash = {}
+
+      _attributes.each do |name|
+        hash[name] = @object.read_attribute_for_serialization(name)
+      end
+
+      hash
+    end
+  end
+end