Refactor partial rendering into a PartialTemplate class. [Pratik]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8976 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 61 insertions, 0 deletions

diff --git a/actionpack/lib/action_view/partial_template.rb b/actionpack/lib/action_view/partial_template.rb
new file mode 100644
index 0000000000..a470c915cd
--- /dev/null
+++ b/actionpack/lib/action_view/partial_template.rb
@@ -0,0 +1,61 @@
+module ActionView #:nodoc:
+  class PartialTemplate < Template #:nodoc:
+    
+    attr_reader :variable_name, :object
+    
+    def initialize(view, partial_path, object = nil, locals = {})
+      @path, @variable_name = extract_partial_name_and_path(view, partial_path)
+      super(view, @path, true, locals)
+      add_object_to_local_assigns!(object)
+      
+      # This is needed here in order to compile template with knowledge of 'counter'
+      initialize_counter
+      
+      # Prepare early. This is a performance optimization for partial collections
+      prepare!
+    end
+    
+    def render
+      ActionController::Base.benchmark("Rendered #{@path}", Logger::DEBUG, false) do
+        @handler.render(self)
+      end
+    end
+    
+    def render_member(object)
+      @locals[@counter_name] += 1
+      @locals[:object] = @locals[@variable_name] = object
+      render
+    end
+    
+    private
+    
+    def add_object_to_local_assigns!(object)
+      @locals[:object] ||=
+        @locals[@variable_name] ||=
+          if object.is_a?(ActionView::Base::ObjectWrapper)
+            object.value
+          else
+            object
+          end || @view.controller.instance_variable_get("@#{variable_name}")
+    end
+    
+    def extract_partial_name_and_path(view, partial_path)
+      path, partial_name = partial_pieces(view, partial_path)
+      [File.join(path, "_#{partial_name}"), partial_name.split('/').last.split('.').first.to_sym] 
+    end
+    
+    def partial_pieces(view, partial_path)
+      if partial_path.include?('/')
+        return File.dirname(partial_path), File.basename(partial_path)
+      else
+        return view.controller.class.controller_path, partial_path
+      end
+    end
+    
+    def initialize_counter
+      @counter_name ||= "#{@variable_name}_counter".to_sym
+      @locals[@counter_name] = 0
+    end
+    
+  end
+end