Add format_with option to exposures + spec.

Author: Robert Ross

lib/grape/entity.rb

@@ -202,6 +202,8 @@ def value_for(attribute, options = {})
         exposure_options[:proc].call(object, options)
       elsif exposure_options[:using]
         exposure_options[:using].represent(object.send(attribute), :root => nil)
+      elsif exposure_options[:format_with]
+        self.send(exposure_options[:format_with].to_sym, object.send(attribute))
       else
         object.send(attribute)
       end

spec/grape/entity_spec.rb

@@ -201,11 +201,12 @@
   context 'instance methods' do
     let(:model){ mock(attributes) }
     let(:attributes){ {
-      :name => 'Bob Bobson',
+      :name => 'Bob Bobson', 
       :email => '[email protected]',
+      :birthday => Time.new(2012, 2, 27),
       :friends => [
-        mock(:name => "Friend 1", :email => '[email protected]', :friends => []),
-        mock(:name => "Friend 2", :email => '[email protected]', :friends => [])
+        mock(:name => "Friend 1", :email => '[email protected]', :birthday => Time.new(2012, 2, 27), :friends => []), 
+        mock(:name => "Friend 2", :email => '[email protected]', :birthday => Time.new(2012, 2, 27), :friends => [])
       ]
     } }
     subject{ fresh_class.new(model) }
@@ -229,6 +230,12 @@
           expose :computed do |object, options|
             options[:awesome]
           end
+
+          expose :birthday, :format_with => :timestamp
+
+          def timestamp(date)
+            date.strftime('%m/%d/%Y')
+          end
         end
       end
 
@@ -261,6 +268,10 @@ class FriendEntity < Grape::Entity
       it 'should call through to the proc if there is one' do
         subject.send(:value_for, :computed, :awesome => 123).should == 123
       end
+
+      it 'should return a formatted value if format_with is passed' do
+        subject.send(:value_for, :birthday).should == '02/27/2012'
+      end
     end
 
     describe '#key_for' do