Add ember-data to --head

lib/generators/ember/install_generator.rb

@@ -35,13 +35,49 @@ def copy_ember
             end
           end
 
-          self.class.source_root File.join(git_root, "dist")
+          source_paths << File.join(git_root, "dist")
 
           copy_file "ember.js", "vendor/assets/ember/development/ember.js"
           copy_file "ember.min.js", "vendor/assets/ember/production/ember.js"
         end
       end
 
+      def copy_ember_data
+        if options.head?
+
+          git_root = File.expand_path "~/.ember-data"
+          gem_file = File.join git_root, "Gemfile"
+
+          # If it doesn't exist yet
+          unless File.exist?(git_root)
+            command = %{git clone git://github.com/emberjs/data.git "#{git_root}"}
+            say_status("downloading", command, :green)
+
+            cmd command
+          else
+            Dir.chdir git_root do
+              command = "git fetch origin && git reset origin/master --hard"
+              say_status("updating", command, :green)
+
+              cmd command
+            end
+          end
+
+          Dir.chdir git_root do
+            say_status("building", "bundle && bundle exec rake", :green)
+            Bundler.with_clean_env do
+              cmd "bundle --gemfile #{gem_file}"
+              cmd %{BUNDLE_GEMFILE="#{gem_file}" bundle exec rake}
+            end
+          end
+
+          source_paths << File.join(git_root, "dist")
+
+          copy_file "ember-data.js", "vendor/assets/ember/development/ember-data.js"
+          copy_file "ember-data.min.js", "vendor/assets/ember/production/ember-data.js"
+        end
+      end
+
       private
 
       def cmd(command)