Added element and collection proxies to RJS [DHH]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3587 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 39 insertions, 0 deletions

diff --git a/actionpack/lib/action_view/helpers/prototype_helper.rb b/actionpack/lib/action_view/helpers/prototype_helper.rb
index 26d877c00a..f0d2b405d2 100644
--- a/actionpack/lib/action_view/helpers/prototype_helper.rb
+++ b/actionpack/lib/action_view/helpers/prototype_helper.rb
@@ -416,6 +416,26 @@ module ActionView
         def to_s #:nodoc:
           @lines * $/
         end
+
+        # Returns a element reference by finding it through +id+ in the DOM. This element can then be
+        # used for further method calls. Examples:
+        #
+        #   page['blank_slate']                  # => $('blank_slate');
+        #   page['blank_slate'].show             # => $('blank_slate').show();
+        #   page['blank_slate'].show('first').up # => $('blank_slate').show('first').up();
+        def [](id)
+          JavaScriptElementProxy.new(self, "$('#{id}')")
+        end
+
+        # Returns a collection reference by finding it through a CSS +pattern+ in the DOM. This collection can then be
+        # used for further method calls. Examples:
+        #
+        #   page.select('p')                      # => $$('p');
+        #   page.select('p.welcome b').first      # => $$('p.welcome b').first();
+        #   page.select('p.welcome b').first.hide # => $$('p.welcome b').first().hide();
+        def select(pattern)
+          JavaScriptElementProxy.new(self, "$$('#{pattern}')")
+        end
   
         # Inserts HTML at the specified +position+ relative to the DOM element
         # identified by the given +id+.
@@ -644,5 +664,24 @@ module ActionView
         callbacks
       end
     end
+
+    # Converts chained method calls on DOM proxy elements into JavaScript chains 
+    class JavaScriptElementProxy < Builder::BlankSlate #:nodoc:
+      def initialize(generator, root)
+        @generator = generator
+        @generator << root
+      end
+      
+      private
+        def method_missing(method, *arguments)
+          method_chain = @generator.instance_variable_get("@lines")
+
+          last_method  = method_chain[-1]
+          method_chain[-1] = last_method[0..-2] if last_method[-1..-1] == ";" # strip trailing ; from last method call
+          method_chain[-1] += ".#{method}(#{@generator.send(:arguments_for_call, arguments)});"
+
+          self
+        end
+    end
   end
 end