fix merge

28 files changed, 520 insertions, 415 deletions

diff --git a/actionpack/lib/action_controller/base.rb b/actionpack/lib/action_controller/base.rb
index a036600c2b..bf34edcd85 100755
--- a/actionpack/lib/action_controller/base.rb
+++ b/actionpack/lib/action_controller/base.rb
@@ -283,13 +283,6 @@ module ActionController #:nodoc:
     @@debug_routes = true
     cattr_accessor :debug_routes
 
-    # Indicates to Mongrel or Webrick whether to allow concurrent action
-    # processing. Your controller actions and any other code they call must
-    # also behave well when called from concurrent threads. Turned off by
-    # default.
-    @@allow_concurrency = false
-    cattr_accessor :allow_concurrency
-
     # Modern REST web services often need to submit complex data to the web application.
     # The <tt>@@param_parsers</tt> hash lets you register handlers which will process the HTTP body and add parameters to the
     # <tt>params</tt> hash. These handlers are invoked for POST and PUT requests.
@@ -428,8 +421,7 @@ module ActionController #:nodoc:
       end
 
       def view_paths=(value)
-        @view_paths = value
-        ActionView::TemplateFinder.process_view_paths(value)
+        @view_paths = ActionView::ViewLoadPaths.new(Array(value)) if value
       end
 
       # Adds a view_path to the front of the view_paths array.
@@ -441,8 +433,7 @@ module ActionController #:nodoc:
       #
       def prepend_view_path(path)
         @view_paths = superclass.view_paths.dup if @view_paths.nil?
-        view_paths.unshift(*path)
-        ActionView::TemplateFinder.process_view_paths(path)
+        @view_paths.unshift(*path)
       end
 
       # Adds a view_path to the end of the view_paths array.
@@ -454,8 +445,7 @@ module ActionController #:nodoc:
       #
       def append_view_path(path)
         @view_paths = superclass.view_paths.dup if @view_paths.nil?
-        view_paths.push(*path)
-        ActionView::TemplateFinder.process_view_paths(path)
+        @view_paths.push(*path)
       end
 
       # Replace sensitive parameter data from the request log.
@@ -613,8 +603,8 @@ module ActionController #:nodoc:
       #
       # This takes the current URL as is and only exchanges the action. In contrast, <tt>url_for :action => 'print'</tt>
       # would have slashed-off the path components after the changed action.
-      def url_for(options = nil) #:doc:
-        case options || {}
+      def url_for(options = {}) #:doc:
+        case options
           when String
             options
           when Hash
@@ -647,11 +637,11 @@ module ActionController #:nodoc:
 
       # View load paths for controller.
       def view_paths
-        @template.finder.view_paths
+        @template.view_paths
       end
 
       def view_paths=(value)
-        @template.finder.view_paths = value  # Mutex needed
+        @template.view_paths = ViewLoadPaths.new(value)
       end
 
       # Adds a view_path to the front of the view_paths array.
@@ -661,7 +651,7 @@ module ActionController #:nodoc:
       #   self.prepend_view_path(["views/default", "views/custom"])
       #
       def prepend_view_path(path)
-        @template.finder.prepend_view_path(path)  # Mutex needed
+        @template.view_paths.unshift(*path)
       end
 
       # Adds a view_path to the end of the view_paths array.
@@ -671,7 +661,7 @@ module ActionController #:nodoc:
       #   self.append_view_path(["views/default", "views/custom"])
       #
       def append_view_path(path)
-        @template.finder.append_view_path(path)  # Mutex needed
+        @template.view_paths.push(*path)
       end
 
     protected
@@ -1232,7 +1222,7 @@ module ActionController #:nodoc:
       end
 
       def template_exists?(template_name = default_template_name)
-        @template.finder.file_exists?(template_name)
+        @template.file_exists?(template_name)
       end
 
       def template_public?(template_name = default_template_name)
@@ -1240,9 +1230,8 @@ module ActionController #:nodoc:
       end
 
       def template_exempt_from_layout?(template_name = default_template_name)
-        extension = @template && @template.finder.pick_template_extension(template_name)
-        name_with_extension = !template_name.include?('.') && extension ? "#{template_name}.#{extension}" : template_name
-        @@exempt_from_layout.any? { |ext| name_with_extension =~ ext }
+        template_name = @template.send(:template_file_from_name, template_name) if @template
+        @@exempt_from_layout.any? { |ext| template_name.to_s =~ ext }
       end
 
       def default_template_name(action_name = self.action_name)
diff --git a/actionpack/lib/action_controller/caching/actions.rb b/actionpack/lib/action_controller/caching/actions.rb
index c4b0a97a33..65a36f7f98 100644
--- a/actionpack/lib/action_controller/caching/actions.rb
+++ b/actionpack/lib/action_controller/caching/actions.rb
@@ -67,10 +67,10 @@ module ActionController #:nodoc:
 
           if options[:action].is_a?(Array)
             options[:action].dup.each do |action|
-              expire_fragment(ActionCachePath.path_for(self, options.merge({ :action => action })))
+              expire_fragment(ActionCachePath.path_for(self, options.merge({ :action => action }), false))
             end
           else
-            expire_fragment(ActionCachePath.path_for(self, options))
+            expire_fragment(ActionCachePath.path_for(self, options, false))
           end
         end
 
@@ -125,16 +125,24 @@ module ActionController #:nodoc:
         attr_reader :path, :extension
 
         class << self
-          def path_for(controller, options)
-            new(controller, options).path
+          def path_for(controller, options, infer_extension=true)
+            new(controller, options, infer_extension).path
           end
         end
-
-        def initialize(controller, options = {})
-          @extension = extract_extension(controller.request.path)
+        
+        # When true, infer_extension will look up the cache path extension from the request's path & format.
+        # This is desirable when reading and writing the cache, but not when expiring the cache -  expire_action should expire the same files regardless of the request format.
+        def initialize(controller, options = {}, infer_extension=true)
+          if infer_extension and options.is_a? Hash
+            request_extension = extract_extension(controller.request)
+            options = options.reverse_merge(:format => request_extension)
+          end
           path = controller.url_for(options).split('://').last
           normalize!(path)
-          add_extension!(path, @extension)
+          if infer_extension
+            @extension = request_extension
+            add_extension!(path, @extension)
+          end
           @path = URI.unescape(path)
         end
 
@@ -144,13 +152,22 @@ module ActionController #:nodoc:
           end
 
           def add_extension!(path, extension)
-            path << ".#{extension}" if extension
+            path << ".#{extension}" if extension and !path.ends_with?(extension)
           end
-
-          def extract_extension(file_path)
+          
+          def extract_extension(request)
             # Don't want just what comes after the last '.' to accommodate multi part extensions
             # such as tar.gz.
-            file_path[/^[^.]+\.(.+)$/, 1]
+            extension = request.path[/^[^.]+\.(.+)$/, 1]
+
+            # If there's no extension in the path, check request.format
+            if extension.nil?
+              extension = request.format.to_sym.to_s
+              if extension=='all'
+                extension = nil
+              end
+            end
+            extension
           end
       end
     end
diff --git a/actionpack/lib/action_controller/dispatcher.rb b/actionpack/lib/action_controller/dispatcher.rb
index fe4f6b4a7e..7df987d525 100644
--- a/actionpack/lib/action_controller/dispatcher.rb
+++ b/actionpack/lib/action_controller/dispatcher.rb
@@ -134,7 +134,7 @@ module ActionController
       run_callbacks :prepare_dispatch
 
       Routing::Routes.reload
-      ActionView::TemplateFinder.reload! unless ActionView::Base.cache_template_loading
+      ActionController::Base.view_paths.reload!
     end
 
     # Cleanup the application by clearing out loaded classes so they can
diff --git a/actionpack/lib/action_controller/integration.rb b/actionpack/lib/action_controller/integration.rb
index bd69d02ed7..18c2df8b37 100644
--- a/actionpack/lib/action_controller/integration.rb
+++ b/actionpack/lib/action_controller/integration.rb
@@ -1,9 +1,10 @@
-require 'stringio'
-require 'uri'
-
+require 'active_support/test_case'
 require 'action_controller/dispatcher'
 require 'action_controller/test_process'
 
+require 'stringio'
+require 'uri'
+
 module ActionController
   module Integration #:nodoc:
     # An integration Session instance represents a set of requests and responses
@@ -580,7 +581,7 @@ EOF
   #         end
   #       end
   #   end
-  class IntegrationTest < Test::Unit::TestCase
+  class IntegrationTest < ActiveSupport::TestCase
     include Integration::Runner
 
     # Work around a bug in test/unit caused by the default test being named
diff --git a/actionpack/lib/action_controller/layout.rb b/actionpack/lib/action_controller/layout.rb
index b5b59f2d7c..0721f71498 100644
--- a/actionpack/lib/action_controller/layout.rb
+++ b/actionpack/lib/action_controller/layout.rb
@@ -304,7 +304,7 @@ module ActionController #:nodoc:
       end
 
       def layout_directory?(layout_name)
-        @template.finder.find_template_extension_from_handler(File.join('layouts', layout_name))
+        @template.view_paths.find_template_file_for_path("#{File.join('layouts', layout_name)}.#{@template.template_format}.erb") ? true : false
       end
   end
 end
diff --git a/actionpack/lib/action_controller/performance_test.rb b/actionpack/lib/action_controller/performance_test.rb
new file mode 100644
index 0000000000..85543fffae
--- /dev/null
+++ b/actionpack/lib/action_controller/performance_test.rb
@@ -0,0 +1,16 @@
+require 'action_controller/integration'
+require 'active_support/testing/performance'
+require 'active_support/testing/default'
+
+module ActionController
+  # An integration test that runs a code profiler on your test methods.
+  # Profiling output for combinations of each test method, measurement, and
+  # output format are written to your tmp/performance directory.
+  #
+  # By default, process_time is measured and both flat and graph_html output
+  # formats are written, so you'll have two output files per test method.
+  class PerformanceTest < ActionController::IntegrationTest
+    include ActiveSupport::Testing::Performance
+    include ActiveSupport::Testing::Default
+  end
+end
diff --git a/actionpack/lib/action_controller/record_identifier.rb b/actionpack/lib/action_controller/record_identifier.rb
index f69c3d6163..742d290ad6 100644
--- a/actionpack/lib/action_controller/record_identifier.rb
+++ b/actionpack/lib/action_controller/record_identifier.rb
@@ -66,12 +66,12 @@ module ActionController
     # The DOM id convention is to use the singular form of an object or class with the id following an underscore.
     # If no id is found, prefix with "new_" instead. Examples:
     #
-    #   dom_id(Post.new(:id => 45)) # => "post_45"
+    #   dom_id(Post.find(45))       # => "post_45"
     #   dom_id(Post.new)            # => "new_post"
     #
     # If you need to address multiple instances of the same class in the same view, you can prefix the dom_id:
     #
-    #   dom_id(Post.new(:id => 45), :edit) # => "edit_post_45"
+    #   dom_id(Post.find(45), :edit) # => "edit_post_45"
     def dom_id(record, prefix = nil) 
       if record_id = record.id
         "#{dom_class(record, prefix)}#{JOIN}#{record_id}"
diff --git a/actionpack/lib/action_controller/resources.rb b/actionpack/lib/action_controller/resources.rb
index 9fb1f9fa39..af2fcaf3ad 100644
--- a/actionpack/lib/action_controller/resources.rb
+++ b/actionpack/lib/action_controller/resources.rb
@@ -72,7 +72,7 @@ module ActionController
       end
 
       def conditions
-        @conditions = @options[:conditions] || {}
+        @conditions ||= @options[:conditions] || {}
       end
 
       def path
@@ -80,9 +80,9 @@ module ActionController
       end
 
       def new_path
-        new_action = self.options[:path_names][:new] if self.options[:path_names]
+        new_action   = self.options[:path_names][:new] if self.options[:path_names]
         new_action ||= Base.resources_path_names[:new]
-        @new_path ||= "#{path}/#{new_action}"
+        @new_path  ||= "#{path}/#{new_action}"
       end
 
       def member_path
diff --git a/actionpack/lib/action_controller/templates/rescues/layout.erb b/actionpack/lib/action_controller/templates/rescues/layout.erb
index d38f3e67f9..4a04742e40 100644
--- a/actionpack/lib/action_controller/templates/rescues/layout.erb
+++ b/actionpack/lib/action_controller/templates/rescues/layout.erb
@@ -1,4 +1,4 @@
-<html>
+<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
   <title>Action Controller: Exception caught</title>
   <style>
diff --git a/actionpack/lib/action_controller/verification.rb b/actionpack/lib/action_controller/verification.rb
index 9f606e7b7c..35b12a7f13 100644
--- a/actionpack/lib/action_controller/verification.rb
+++ b/actionpack/lib/action_controller/verification.rb
@@ -116,7 +116,7 @@ module ActionController #:nodoc:
     end
     
     def apply_redirect_to(redirect_to_option) # :nodoc:
-      redirect_to_option.is_a?(Symbol) ? self.send!(redirect_to_option) : redirect_to_option
+      (redirect_to_option.is_a?(Symbol) && redirect_to_option != :back) ? self.send!(redirect_to_option) : redirect_to_option
     end
     
     def apply_remaining_actions(options) # :nodoc:
diff --git a/actionpack/lib/action_view.rb b/actionpack/lib/action_view.rb
index 5f4126e4e9..973020a768 100644
--- a/actionpack/lib/action_view.rb
+++ b/actionpack/lib/action_view.rb
@@ -21,13 +21,9 @@
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #++
 
-require 'action_view/template_handler'
-require 'action_view/template_handlers/compilable'
-require 'action_view/template_handlers/builder'
-require 'action_view/template_handlers/erb'
-require 'action_view/template_handlers/rjs'
-
-require 'action_view/template_finder'
+require 'action_view/template_handlers'
+require 'action_view/template_file'
+require 'action_view/view_load_paths'
 require 'action_view/template'
 require 'action_view/partial_template'
 require 'action_view/inline_template'
diff --git a/actionpack/lib/action_view/base.rb b/actionpack/lib/action_view/base.rb
index eeebf335dc..4f3cc46a14 100644
--- a/actionpack/lib/action_view/base.rb
+++ b/actionpack/lib/action_view/base.rb
@@ -1,17 +1,17 @@
 module ActionView #:nodoc:
   class ActionViewError < StandardError #:nodoc:
   end
-  
+
   class MissingTemplate < ActionViewError #:nodoc:
   end
 
-  # Action View templates can be written in three ways. If the template file has a <tt>.erb</tt> (or <tt>.rhtml</tt>) extension then it uses a mixture of ERb 
-  # (included in Ruby) and HTML. If the template file has a <tt>.builder</tt> (or <tt>.rxml</tt>) extension then Jim Weirich's Builder::XmlMarkup library is used. 
+  # Action View templates can be written in three ways. If the template file has a <tt>.erb</tt> (or <tt>.rhtml</tt>) extension then it uses a mixture of ERb
+  # (included in Ruby) and HTML. If the template file has a <tt>.builder</tt> (or <tt>.rxml</tt>) extension then Jim Weirich's Builder::XmlMarkup library is used.
   # If the template file has a <tt>.rjs</tt> extension then it will use ActionView::Helpers::PrototypeHelper::JavaScriptGenerator.
-  # 
+  #
   # = ERb
-  # 
-  # You trigger ERb by using embeddings such as <% %>, <% -%>, and <%= %>. The <%= %> tag set is used when you want output. Consider the 
+  #
+  # You trigger ERb by using embeddings such as <% %>, <% -%>, and <%= %>. The <%= %> tag set is used when you want output. Consider the
   # following loop for names:
   #
   #   <b>Names of all the people</b>
@@ -51,7 +51,7 @@ module ActionView #:nodoc:
   #   <title><%= @page_title %></title>
   #
   # == Passing local variables to sub templates
-  # 
+  #
   # You can pass local variables to sub templates by using a hash with the variable names as keys and the objects as values:
   #
   #   <%= render "shared/header", { :headline => "Welcome", :person => person } %>
@@ -77,8 +77,8 @@ module ActionView #:nodoc:
   #
   # == Builder
   #
-  # Builder templates are a more programmatic alternative to ERb. They are especially useful for generating XML content. An XmlMarkup object 
-  # named +xml+ is automatically made available to templates with a <tt>.builder</tt> extension. 
+  # Builder templates are a more programmatic alternative to ERb. They are especially useful for generating XML content. An XmlMarkup object
+  # named +xml+ is automatically made available to templates with a <tt>.builder</tt> extension.
   #
   # Here are some basic examples:
   #
@@ -87,7 +87,7 @@ module ActionView #:nodoc:
   #   xml.a("A Link", "href"=>"http://onestepback.org") # => <a href="http://onestepback.org">A Link</a>
   #   xml.target("name"=>"compile", "option"=>"fast")   # => <target option="fast" name="compile"\>
   #                                                     # NOTE: order of attributes is not specified.
-  # 
+  #
   # Any method with a block will be treated as an XML markup tag with nested markup in the block. For example, the following:
   #
   #   xml.div {
@@ -111,7 +111,7 @@ module ActionView #:nodoc:
   #       xml.description "Basecamp: Recent items"
   #       xml.language "en-us"
   #       xml.ttl "40"
-  # 
+  #
   #       for item in @recent_items
   #         xml.item do
   #           xml.title(item_title(item))
@@ -119,7 +119,7 @@ module ActionView #:nodoc:
   #           xml.pubDate(item_pubDate(item))
   #           xml.guid(@person.firm.account.url + @recent_items.url(item))
   #           xml.link(@person.firm.account.url + @recent_items.url(item))
-  #       
+  #
   #           xml.tag!("dc:creator", item.author_name) if item_has_creator?(item)
   #         end
   #       end
@@ -130,12 +130,12 @@ module ActionView #:nodoc:
   #
   # == JavaScriptGenerator
   #
-  # JavaScriptGenerator templates end in <tt>.rjs</tt>. Unlike conventional templates which are used to 
-  # render the results of an action, these templates generate instructions on how to modify an already rendered page. This makes it easy to 
-  # modify multiple elements on your page in one declarative Ajax response. Actions with these templates are called in the background with Ajax 
+  # JavaScriptGenerator templates end in <tt>.rjs</tt>. Unlike conventional templates which are used to
+  # render the results of an action, these templates generate instructions on how to modify an already rendered page. This makes it easy to
+  # modify multiple elements on your page in one declarative Ajax response. Actions with these templates are called in the background with Ajax
   # and make updates to the page where the request originated from.
-  # 
-  # An instance of the JavaScriptGenerator object named +page+ is automatically made available to your template, which is implicitly wrapped in an ActionView::Helpers::PrototypeHelper#update_page block. 
+  #
+  # An instance of the JavaScriptGenerator object named +page+ is automatically made available to your template, which is implicitly wrapped in an ActionView::Helpers::PrototypeHelper#update_page block.
   #
   # When an <tt>.rjs</tt> action is called with +link_to_remote+, the generated JavaScript is automatically evaluated.  Example:
   #
@@ -145,15 +145,14 @@ module ActionView #:nodoc:
   #
   #   page.replace_html  'sidebar', :partial => 'sidebar'
   #   page.remove        "person-#{@person.id}"
-  #   page.visual_effect :highlight, 'user-list' 
+  #   page.visual_effect :highlight, 'user-list'
   #
   # This refreshes the sidebar, removes a person element and highlights the user list.
-  # 
+  #
   # See the ActionView::Helpers::PrototypeHelper::GeneratorMethods documentation for more details.
   class Base
     include ERB::Util
 
-    attr_reader   :finder
     attr_accessor :base_path, :assigns, :template_extension, :first_render
     attr_accessor :controller
 
@@ -170,22 +169,22 @@ module ActionView #:nodoc:
     # Specify whether file modification times should be checked to see if a template needs recompilation
     @@cache_template_loading = false
     cattr_accessor :cache_template_loading
-    
+
     def self.cache_template_extensions=(*args)
       ActiveSupport::Deprecation.warn("config.action_view.cache_template_extensions option has been deprecated and has no affect. " <<
                                        "Please remove it from your config files.", caller)
     end
 
     # Specify whether RJS responses should be wrapped in a try/catch block
-    # that alert()s the caught exception (and then re-raises it). 
+    # that alert()s the caught exception (and then re-raises it).
     @@debug_rjs = false
     cattr_accessor :debug_rjs
 
     attr_internal :request
 
     delegate :request_forgery_protection_token, :template, :params, :session, :cookies, :response, :headers,
-             :flash, :logger, :action_name, :to => :controller
- 
+             :flash, :logger, :action_name, :controller_name, :to => :controller
+
     module CompiledTemplates #:nodoc:
       # holds compiled template code
     end
@@ -221,11 +220,17 @@ module ActionView #:nodoc:
       @assigns = assigns_for_first_render
       @assigns_added = nil
       @controller = controller
-      @finder = TemplateFinder.new(self, view_paths)
+      self.view_paths = view_paths
     end
 
-    # Renders the template present at <tt>template_path</tt>. If <tt>use_full_path</tt> is set to true, 
-    # it's relative to the view_paths array, otherwise it's absolute. The hash in <tt>local_assigns</tt> 
+    attr_reader :view_paths
+
+    def view_paths=(paths)
+      @view_paths = ViewLoadPaths.new(Array(paths))
+    end
+
+    # Renders the template present at <tt>template_path</tt>. If <tt>use_full_path</tt> is set to true,
+    # it's relative to the view_paths array, otherwise it's absolute. The hash in <tt>local_assigns</tt>
     # is made available as local variables.
     def render_file(template_path, use_full_path = true, local_assigns = {}) #:nodoc:
       if defined?(ActionMailer) && defined?(ActionMailer::Base) && controller.is_a?(ActionMailer::Base) && !template_path.include?("/")
@@ -240,11 +245,11 @@ If you are rendering a subtemplate, you must now use controller-like partial syn
   render :partial => 'signup' # no mailer_name necessary
         END_ERROR
       end
-      
+
       Template.new(self, template_path, use_full_path, local_assigns).render_template
     end
-    
-    # Renders the template present at <tt>template_path</tt> (relative to the view_paths array). 
+
+    # Renders the template present at <tt>template_path</tt> (relative to the view_paths array).
     # The hash in <tt>local_assigns</tt> is made available as local variables.
     def render(options = {}, local_assigns = {}, &block) #:nodoc:
       if options.is_a?(String)
@@ -257,7 +262,7 @@ If you are rendering a subtemplate, you must now use controller-like partial syn
 
         if partial_layout = options.delete(:layout)
           if block_given?
-            wrap_content_for_layout capture(&block) do 
+            wrap_content_for_layout capture(&block) do
               concat(render(options.merge(:partial => partial_layout)))
             end
           else
@@ -314,6 +319,10 @@ If you are rendering a subtemplate, you must now use controller-like partial syn
       end
     end
 
+    def file_exists?(template_path)
+      view_paths.template_exists?(template_file_from_name(template_path))
+    end
+
     private
       def wrap_content_for_layout(content)
         original_content_for_layout, @content_for_layout = @content_for_layout, content
@@ -334,11 +343,43 @@ If you are rendering a subtemplate, you must now use controller-like partial syn
       def assign_variables_from_controller
         @assigns.each { |key, value| instance_variable_set("@#{key}", value) }
       end
-      
+
       def execute(template)
         send(template.method, template.locals) do |*names|
           instance_variable_get "@content_for_#{names.first || 'layout'}"
-        end        
+        end
+      end
+
+      def template_file_from_name(template_name)
+        template_name = TemplateFile.from_path(template_name)
+        pick_template_extension(template_name) unless template_name.extension
+      end
+
+      # Gets the extension for an existing template with the given template_path.
+      # Returns the format with the extension if that template exists.
+      #
+      #   pick_template_extension('users/show')
+      #   # => 'html.erb'
+      #
+      #   pick_template_extension('users/legacy')
+      #   # => "rhtml"
+      #
+      def pick_template_extension(file)
+        if f = self.view_paths.find_template_file_for_path(file.dup_with_extension(template_format)) || file_from_first_render(file)
+          f
+        elsif template_format == :js && f = self.view_paths.find_template_file_for_path(file.dup_with_extension(:html))
+          @template_format = :html
+          f
+        else
+          nil
+        end
+      end
+
+      # Determine the template extension from the <tt>@first_render</tt> filename
+      def file_from_first_render(file)
+        if extension = File.basename(@first_render.to_s)[/^[^.]+\.(.+)$/, 1]
+          file.dup_with_extension(extension)
+        end
       end
   end
 end
diff --git a/actionpack/lib/action_view/helpers/capture_helper.rb b/actionpack/lib/action_view/helpers/capture_helper.rb
index 25e62f78fb..9cd9d3d06a 100644
--- a/actionpack/lib/action_view/helpers/capture_helper.rb
+++ b/actionpack/lib/action_view/helpers/capture_helper.rb
@@ -31,7 +31,7 @@ module ActionView
       #   </body></html>
       #
       def capture(*args, &block)
-        if @output_buffer
+        if output_buffer
           with_output_buffer { block.call(*args) }
         else
           block.call(*args)
@@ -121,10 +121,11 @@ module ActionView
 
       private
         def with_output_buffer(buf = '')
-          @output_buffer, old_buffer = buf, @output_buffer
+          self.output_buffer, old_buffer = buf, output_buffer
           yield
+          output_buffer
         ensure
-          @output_buffer = old_buffer
+          self.output_buffer = old_buffer
         end
     end
   end
diff --git a/actionpack/lib/action_view/helpers/form_options_helper.rb b/actionpack/lib/action_view/helpers/form_options_helper.rb
index 90bd99a861..b3f8e63c1b 100644
--- a/actionpack/lib/action_view/helpers/form_options_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_options_helper.rb
@@ -304,7 +304,7 @@ module ActionView
       #
       # NOTE: Only the option tags are returned, you have to wrap this call in
       # a regular HTML select tag.
-      def time_zone_options_for_select(selected = nil, priority_zones = nil, model = ActiveSupport::TimeZone)
+      def time_zone_options_for_select(selected = nil, priority_zones = nil, model = ::ActiveSupport::TimeZone)
         zone_options = ""
 
         zones = model.all
diff --git a/actionpack/lib/action_view/helpers/javascript_helper.rb b/actionpack/lib/action_view/helpers/javascript_helper.rb
index 85b205c264..7404a251e4 100644
--- a/actionpack/lib/action_view/helpers/javascript_helper.rb
+++ b/actionpack/lib/action_view/helpers/javascript_helper.rb
@@ -202,11 +202,6 @@ module ActionView
         end
         js_option
       end
-
-    private
-      def block_is_within_action_view?(block)
-        !@output_buffer.nil?
-      end
     end
     
     JavascriptHelper = JavaScriptHelper unless const_defined? :JavascriptHelper
diff --git a/actionpack/lib/action_view/helpers/tag_helper.rb b/actionpack/lib/action_view/helpers/tag_helper.rb
index a8a5987b1f..e1abec1847 100644
--- a/actionpack/lib/action_view/helpers/tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/tag_helper.rb
@@ -122,10 +122,6 @@ module ActionView
             " #{attrs.sort * ' '}" unless attrs.empty?
           end
         end
-
-        def block_is_within_action_view?(block)
-          !@output_buffer.nil?
-        end
     end
   end
 end
diff --git a/actionpack/lib/action_view/helpers/text_helper.rb b/actionpack/lib/action_view/helpers/text_helper.rb
index 3077c8f970..a1a91f6b3d 100644
--- a/actionpack/lib/action_view/helpers/text_helper.rb
+++ b/actionpack/lib/action_view/helpers/text_helper.rb
@@ -29,8 +29,9 @@ module ActionView
         if unused_binding
           ActiveSupport::Deprecation.warn("The binding argument of #concat is no longer needed.  Please remove it from your views and helpers.")
         end
-        if @output_buffer && string
-          @output_buffer << string
+
+        if output_buffer && string
+          output_buffer << string
         else
           string
         end
diff --git a/actionpack/lib/action_view/helpers/url_helper.rb b/actionpack/lib/action_view/helpers/url_helper.rb
index 4b12adf225..baecd304cd 100644
--- a/actionpack/lib/action_view/helpers/url_helper.rb
+++ b/actionpack/lib/action_view/helpers/url_helper.rb
@@ -90,6 +90,13 @@ module ActionView
       # link will be used in place of a referrer if none exists. If nil is passed as
       # a name, the link itself will become the name.
       #
+      # ==== Signatures
+      #
+      #   link_to(name, options = {}, html_options = nil)
+      #   link_to(options = {}, html_options = nil) do
+      #     # name
+      #   end
+      #
       # ==== Options
       # * <tt>:confirm => 'question?'</tt> - This will add a JavaScript confirm
       #   prompt with the question specified. If the user accepts, the link is
@@ -147,6 +154,13 @@ module ActionView
       #   link_to "Profiles", :controller => "profiles"
       #   # => <a href="/profiles">Profiles</a>
       #
+      # You can use a block as well if your link target is hard to fit into the name parameter. ERb example:
+      #
+      #   <% link_to(@profile) do %>
+      #     <strong><%= @profile.name %></strong> -- <span>Check it out!!</span>
+      #   <% end %>
+      #   # => <a href="/profiles/1"><strong>David</strong> -- <span>Check it out!!</span></a>
+      #
       # Classes and ids for CSS are easy to produce:
       #
       #   link_to "Articles", articles_path, :id => "news", :class => "article"
@@ -189,27 +203,37 @@ module ActionView
       #        f.style.display = 'none'; this.parentNode.appendChild(f); f.method = 'POST'; f.action = this.href;
       #        var m = document.createElement('input'); m.setAttribute('type', 'hidden'); m.setAttribute('name', '_method'); 
       #        m.setAttribute('value', 'delete'); f.appendChild(m);f.submit(); };return false;">Delete Image</a>
-      def link_to(name, options = {}, html_options = nil)
-        url = case options
-          when String
-            options
-          when :back
-            @controller.request.env["HTTP_REFERER"] || 'javascript:history.back()'
+      def link_to(*args, &block)
+        if block_given?
+          options      = args.first || {}
+          html_options = args.second
+          concat(link_to(capture(&block), options, html_options))
+        else
+          name         = args.first
+          options      = args.second || {}
+          html_options = args.third
+
+          url = case options
+            when String
+              options
+            when :back
+              @controller.request.env["HTTP_REFERER"] || 'javascript:history.back()'
+            else
+              self.url_for(options)
+            end
+
+          if html_options
+            html_options = html_options.stringify_keys
+            href = html_options['href']
+            convert_options_to_javascript!(html_options, url)
+            tag_options = tag_options(html_options)
           else
-            self.url_for(options)
+            tag_options = nil
           end
-
-        if html_options
-          html_options = html_options.stringify_keys
-          href = html_options['href']
-          convert_options_to_javascript!(html_options, url)
-          tag_options = tag_options(html_options)
-        else
-          tag_options = nil
+      
+          href_attr = "href=\"#{url}\"" unless href
+          "<a #{href_attr}#{tag_options}>#{name || url}</a>"
         end
-        
-        href_attr = "href=\"#{url}\"" unless href
-        "<a #{href_attr}#{tag_options}>#{name || url}</a>"
       end
 
       # Generates a form containing a single button that submits to the URL created
diff --git a/actionpack/lib/action_view/inline_template.rb b/actionpack/lib/action_view/inline_template.rb
index 87c012d181..fd0ad48302 100644
--- a/actionpack/lib/action_view/inline_template.rb
+++ b/actionpack/lib/action_view/inline_template.rb
@@ -1,20 +1,17 @@
 module ActionView #:nodoc:
   class InlineTemplate < Template #:nodoc:
-    
     def initialize(view, source, locals = {}, type = nil)
       @view = view
-      @finder = @view.finder
-      
+
       @source = source
       @extension = type
       @locals = locals || {}
-      
+
       @handler = self.class.handler_class_for_extension(@extension).new(@view)
     end
-    
+
     def method_key
       @source
     end
-    
   end
 end
diff --git a/actionpack/lib/action_view/partial_template.rb b/actionpack/lib/action_view/partial_template.rb
index 0b374db888..0cf996ca04 100644
--- a/actionpack/lib/action_view/partial_template.rb
+++ b/actionpack/lib/action_view/partial_template.rb
@@ -1,70 +1,70 @@
 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)
+      @view_controller = view.controller if view.respond_to?(:controller)
+      set_path_and_variable_name!(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
-      
+      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
+      ActionController::Base.benchmark("Rendered #{@path.path_without_format_and_extension}", Logger::DEBUG, false) do
         @handler.render(self)
       end
     end
-    
+
     def render_member(object)
       @locals[:object] = @locals[@variable_name] = object
-      
+
       template = render_template
       @locals[@counter_name] += 1
       @locals.delete(@variable_name)
       @locals.delete(:object)
-      
+
       template
     end
-    
+
     def counter=(num)
       @locals[@counter_name] = num
     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 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
+      def set_path_and_variable_name!(partial_path)
+        if partial_path.include?('/')
+          @variable_name = File.basename(partial_path)
+          @path = "#{File.dirname(partial_path)}/_#{@variable_name}"
+        elsif @view_controller
+          @variable_name = partial_path
+          @path = "#{@view_controller.class.controller_path}/_#{@variable_name}"
+        else
+          @variable_name = partial_path
+          @path = "_#{@variable_name}"
+        end
+
+        @variable_name = @variable_name.sub(/\..*$/, '').to_sym
+      end
+
+      def initialize_counter!
+        @counter_name ||= "#{@variable_name}_counter".to_sym
+        @locals[@counter_name] = 0
       end
-    end
-    
-    def initialize_counter
-      @counter_name ||= "#{@variable_name}_counter".to_sym
-      @locals[@counter_name] = 0
-    end
-    
   end
 end
diff --git a/actionpack/lib/action_view/template.rb b/actionpack/lib/action_view/template.rb
index 369526188f..4c3f252c10 100644
--- a/actionpack/lib/action_view/template.rb
+++ b/actionpack/lib/action_view/template.rb
@@ -1,19 +1,20 @@
 module ActionView #:nodoc:
   class Template #:nodoc:
+    extend TemplateHandlers
 
     attr_accessor :locals
-    attr_reader :handler, :path, :extension, :filename, :path_without_extension, :method
+    attr_reader :handler, :path, :extension, :filename, :method
 
     def initialize(view, path, use_full_path, locals = {})
       @view = view
-      @finder = @view.finder
+      @paths = view.view_paths
 
-      # Clear the forward slash at the beginning if exists
-      @path = use_full_path ? path.sub(/^\//, '') : path
-      @view.first_render ||= @path
+      @original_path = path
+      @path = TemplateFile.from_path(path, !use_full_path)
+      @view.first_render ||= @path.to_s
       @source = nil # Don't read the source until we know that it is required
       set_extension_and_file_name(use_full_path)
-      
+
       @locals = locals || {}
       @handler = self.class.handler_class_for_extension(@extension).new(@view)
     end
@@ -29,12 +30,16 @@ module ActionView #:nodoc:
         raise TemplateError.new(self, @view.assigns, e)
       end
     end
-    
+
     def render
       prepare!
       @handler.render(self)
     end
 
+    def path_without_extension
+      @path.path_without_extension
+    end
+
     def source
       @source ||= File.read(self.filename)
     end
@@ -44,13 +49,13 @@ module ActionView #:nodoc:
     end
 
     def base_path_for_exception
-      @finder.find_base_path_for("#{@path_without_extension}.#{@extension}") || @finder.view_paths.first
+      (@paths.find_load_path_for_path(@path) || @paths.first).to_s
     end
-    
+
     def prepare!
       @view.send :evaluate_assigns
       @view.current_render_extension = @extension
-      
+
       if @handler.compilable?
         @handler.compile_template(self) # compile the given template, if necessary
         @method = @view.method_names[method_key] # Set the method name for this template and run it
@@ -58,70 +63,32 @@ module ActionView #:nodoc:
     end
 
     private
-
-    def set_extension_and_file_name(use_full_path)
-      @path_without_extension, @extension = @finder.path_and_extension(@path)
-      if use_full_path
-        if @extension
-          @filename = @finder.pick_template(@path_without_extension, @extension)
+      def set_extension_and_file_name(use_full_path)
+        @extension = @path.extension
+
+        if use_full_path
+          unless @extension
+            @path = @view.send(:template_file_from_name, @path)
+            raise_missing_template_exception unless @path
+            @extension = @path.extension
+          end
+
+          if @path = @paths.find_template_file_for_path(path)
+            @filename = @path.full_path
+            @extension = @path.extension
+          end
         else
-          @extension = @finder.pick_template_extension(@path).to_s
-          raise_missing_template_exception unless @extension
-          
-          @filename = @finder.pick_template(@path, @extension)
-          @extension = @extension.gsub(/^.+\./, '') # strip off any formats
+          @filename = @path.full_path
         end
-      else
-        @filename = @path
-      end
-
-      raise_missing_template_exception if @filename.blank?
-    end
-    
-    def raise_missing_template_exception
-      full_template_path = @path.include?('.') ? @path : "#{@path}.#{@view.template_format}.erb"
-      display_paths = @finder.view_paths.join(':')
-      template_type = (@path =~ /layouts/i) ? 'layout' : 'template'
-      raise(MissingTemplate, "Missing #{template_type} #{full_template_path} in view path #{display_paths}")
-    end
-
-    # Template Handlers
-    
-    @@template_handlers = HashWithIndifferentAccess.new
-    @@default_template_handlers = nil
-    
-    # Register a class that knows how to handle template files with the given
-    # extension. This can be used to implement new template types.
-    # The constructor for the class must take the ActiveView::Base instance
-    # as a parameter, and the class must implement a +render+ method that
-    # takes the contents of the template to render as well as the Hash of
-    # local assigns available to the template. The +render+ method ought to
-    # return the rendered template as a string.
-    def self.register_template_handler(extension, klass)
-      @@template_handlers[extension.to_sym] = klass
-      TemplateFinder.update_extension_cache_for(extension.to_s)
-    end
 
-    def self.template_handler_extensions
-      @@template_handlers.keys.map(&:to_s).sort
-    end
-
-    def self.register_default_template_handler(extension, klass)
-      register_template_handler(extension, klass)
-      @@default_template_handlers = klass
-    end
-
-    def self.handler_class_for_extension(extension)
-      (extension && @@template_handlers[extension.to_sym]) || @@default_template_handlers
-    end
-
-    register_default_template_handler :erb, TemplateHandlers::ERB
-    register_template_handler :rjs, TemplateHandlers::RJS
-    register_template_handler :builder, TemplateHandlers::Builder
+        raise_missing_template_exception if @filename.blank?
+      end
 
-    # TODO: Depreciate old template extensions
-    register_template_handler :rhtml, TemplateHandlers::ERB
-    register_template_handler :rxml, TemplateHandlers::Builder
-    
+      def raise_missing_template_exception
+        full_template_path = @original_path.include?('.') ? @original_path : "#{@original_path}.#{@view.template_format}.erb"
+        display_paths = @paths.join(':')
+        template_type = (@original_path =~ /layouts/i) ? 'layout' : 'template'
+        raise(MissingTemplate, "Missing #{template_type} #{full_template_path} in view path #{display_paths}")
+      end
   end
 end
diff --git a/actionpack/lib/action_view/template_file.rb b/actionpack/lib/action_view/template_file.rb
new file mode 100644
index 0000000000..dd66482b3c
--- /dev/null
+++ b/actionpack/lib/action_view/template_file.rb
@@ -0,0 +1,88 @@
+module ActionView #:nodoc:
+  # TemplateFile abstracts the pattern of querying a file path for its
+  # path with or without its extension. The path is only the partial path
+  # from the load path root e.g. "hello/index.html.erb" not
+  # "app/views/hello/index.html.erb"
+  class TemplateFile
+    def self.from_path(path, use_full_path = false)
+      path.is_a?(self) ? path : new(path, use_full_path)
+    end
+
+    def self.from_full_path(load_path, full_path)
+      file = new(full_path.split(load_path).last)
+      file.load_path = load_path
+      file.freeze
+    end
+
+    attr_accessor :load_path, :base_path, :name, :format, :extension
+    delegate :to_s, :inspect, :to => :path
+
+    def initialize(path, use_full_path = false)
+      path = path.dup
+
+      # Clear the forward slash in the beginning unless using full path
+      trim_forward_slash!(path) unless use_full_path
+
+      @base_path, @name, @format, @extension = split(path)
+    end
+
+    def freeze
+      @load_path.freeze
+      @base_path.freeze
+      @name.freeze
+      @format.freeze
+      @extension.freeze
+      super
+    end
+
+    def format_and_extension
+      extensions = [format, extension].compact.join(".")
+      extensions.blank? ? nil : extensions
+    end
+
+    def full_path
+      if load_path
+        "#{load_path}/#{path}"
+      else
+        path
+      end
+    end
+
+    def path
+      base_path.to_s + [name, format, extension].compact.join(".")
+    end
+
+    def path_without_extension
+      base_path.to_s + [name, format].compact.join(".")
+    end
+
+    def path_without_format_and_extension
+      "#{base_path}#{name}"
+    end
+
+    def dup_with_extension(extension)
+      file = dup
+      file.extension = extension ? extension.to_s : nil
+      file
+    end
+
+    private
+      def trim_forward_slash!(path)
+        path.sub!(/^\//, '')
+      end
+
+      # Returns file split into an array
+      #   [base_path, name, format, extension]
+      def split(file)
+        if m = file.match(/^(.*\/)?(\w+)\.?(\w+)?\.?(\w+)?\.?(\w+)?$/)
+          if m[5] # Mulipart formats
+            [m[1], m[2], "#{m[3]}.#{m[4]}", m[5]]
+          elsif m[4] # Single format
+            [m[1], m[2], m[3], m[4]]
+          else # No format
+            [m[1], m[2], nil, m[3]]
+          end
+        end
+      end
+  end
+end
diff --git a/actionpack/lib/action_view/template_finder.rb b/actionpack/lib/action_view/template_finder.rb
deleted file mode 100644
index 83b7e27c09..0000000000
--- a/actionpack/lib/action_view/template_finder.rb
+++ /dev/null
@@ -1,177 +0,0 @@
-module ActionView #:nodoc:
-  class TemplateFinder #:nodoc:
-
-    class InvalidViewPath < StandardError #:nodoc:
-      attr_reader :unprocessed_path
-      def initialize(path)
-        @unprocessed_path = path
-        super("Unprocessed view path found: #{@unprocessed_path.inspect}.  Set your view paths with #append_view_path, #prepend_view_path, or #view_paths=.")
-      end
-    end
-
-    cattr_reader :processed_view_paths
-    @@processed_view_paths = Hash.new {|hash, key| hash[key] = []}
-
-    cattr_reader :file_extension_cache
-    @@file_extension_cache = Hash.new {|hash, key|
-      hash[key] = Hash.new {|hash, key| hash[key] = []}
-    }
-
-    class << self #:nodoc:
-
-      # This method is not thread safe. Mutex should be used whenever this is accessed from an instance method
-      def process_view_paths(*view_paths)
-        view_paths.flatten.compact.each do |dir|
-          next if @@processed_view_paths.has_key?(dir)
-          @@processed_view_paths[dir] = []
-          
-          # 
-          # Dir.glob("#{dir}/**/*/**") reads all the directories in view path and templates inside those directories
-          # Dir.glob("#{dir}/**") reads templates residing at top level of view path
-          # 
-          (Dir.glob("#{dir}/**/*/**") | Dir.glob("#{dir}/**")).each do |file|
-            unless File.directory?(file)
-              @@processed_view_paths[dir] << file.split(dir).last.sub(/^\//, '')
-
-              # Build extension cache
-              extension = file.split(".").last
-              if template_handler_extensions.include?(extension)
-                key = file.split(dir).last.sub(/^\//, '').sub(/\.(\w+)$/, '')
-                @@file_extension_cache[dir][key] << extension
-              end
-            end
-          end
-        end
-      end
-
-      def update_extension_cache_for(extension)
-        @@processed_view_paths.keys.each do |dir|
-          Dir.glob("#{dir}/**/*.#{extension}").each do |file|
-            key = file.split(dir).last.sub(/^\//, '').sub(/\.(\w+)$/, '')
-            @@file_extension_cache[dir][key] << extension
-          end
-        end
-      end
-
-      def template_handler_extensions
-        ActionView::Template.template_handler_extensions
-      end
-
-      def reload!
-        view_paths = @@processed_view_paths.keys
-
-        @@processed_view_paths = Hash.new {|hash, key| hash[key] = []}
-        @@file_extension_cache = Hash.new {|hash, key|
-          hash[key] = Hash.new {|hash, key| hash[key] = []}
-        }
-
-        process_view_paths(view_paths)
-      end
-    end
-
-    attr_accessor :view_paths
-
-    def initialize(*args)
-      @template = args.shift
-
-      @view_paths = args.flatten
-      @view_paths = @view_paths.respond_to?(:find) ? @view_paths.dup : [*@view_paths].compact
-      check_view_paths(@view_paths)
-    end
-
-    def prepend_view_path(path)
-      @view_paths.unshift(*path)
-
-      self.class.process_view_paths(path)
-    end
-
-    def append_view_path(path)
-      @view_paths.push(*path)
-
-      self.class.process_view_paths(path)
-    end
-
-    def view_paths=(path)
-      @view_paths = path
-      self.class.process_view_paths(path)
-    end
-
-    def pick_template(template_path, extension)
-      file_name = "#{template_path}.#{extension}"
-      base_path = find_base_path_for(file_name)
-      base_path.blank? ? false : "#{base_path}/#{file_name}"
-    end
-    alias_method :template_exists?, :pick_template
-
-    def file_exists?(template_path)
-      # Clear the forward slash in the beginning if exists
-      template_path = template_path.sub(/^\//, '')
-
-      template_file_name, template_file_extension = path_and_extension(template_path)
-
-      if template_file_extension
-        template_exists?(template_file_name, template_file_extension)
-      else
-        template_exists?(template_file_name, pick_template_extension(template_path))
-      end
-    end
-
-    def find_base_path_for(template_file_name)
-      @view_paths.find { |path| @@processed_view_paths[path].include?(template_file_name) }
-    end
-
-    # Returns the view path that the full path resides in.
-    def extract_base_path_from(full_path)
-      @view_paths.find { |p| full_path[0..p.size - 1] == p }
-    end
-
-    # Gets the extension for an existing template with the given template_path.
-    # Returns the format with the extension if that template exists.
-    #
-    #   pick_template_extension('users/show')
-    #   # => 'html.erb'
-    #
-    #   pick_template_extension('users/legacy')
-    #   # => "rhtml"
-    #
-    def pick_template_extension(template_path)
-      if extension = find_template_extension_from_handler(template_path, @template.template_format) || find_template_extension_from_first_render
-        extension
-      elsif @template.template_format == :js && extension = find_template_extension_from_handler(template_path, :html)
-        @template.template_format = :html
-        extension
-      end
-    end
-
-    def find_template_extension_from_handler(template_path, template_format = @template.template_format)
-      formatted_template_path = "#{template_path}.#{template_format}"
-
-      view_paths.each do |path|
-        if (extensions = @@file_extension_cache[path][formatted_template_path]).any?
-          return "#{template_format}.#{extensions.first}"
-        elsif (extensions = @@file_extension_cache[path][template_path]).any?
-          return extensions.first.to_s
-        end
-      end
-      nil
-    end
-
-    # Splits the path and extension from the given template_path and returns as an array.
-    def path_and_extension(template_path)
-      template_path_without_extension = template_path.sub(/\.(\w+)$/, '')
-      [ template_path_without_extension, $1 ]
-    end
-
-    # Determine the template extension from the <tt>@first_render</tt> filename
-    def find_template_extension_from_first_render
-      File.basename(@template.first_render.to_s)[/^[^.]+\.(.+)$/, 1]
-    end
-
-    private
-      def check_view_paths(view_paths)
-        view_paths.each do |path|
-          raise InvalidViewPath.new(path) unless @@processed_view_paths.has_key?(path)
-        end
-      end
-  end
-end
diff --git a/actionpack/lib/action_view/template_handler.rb b/actionpack/lib/action_view/template_handler.rb
index ec407e3fb3..39e578e586 100644
--- a/actionpack/lib/action_view/template_handler.rb
+++ b/actionpack/lib/action_view/template_handler.rb
@@ -1,6 +1,5 @@
 module ActionView
   class TemplateHandler
-
     def self.line_offset
       0
     end
diff --git a/actionpack/lib/action_view/template_handlers.rb b/actionpack/lib/action_view/template_handlers.rb
new file mode 100644
index 0000000000..1471e99e01
--- /dev/null
+++ b/actionpack/lib/action_view/template_handlers.rb
@@ -0,0 +1,46 @@
+require 'action_view/template_handler'
+require 'action_view/template_handlers/compilable'
+require 'action_view/template_handlers/builder'
+require 'action_view/template_handlers/erb'
+require 'action_view/template_handlers/rjs'
+
+module ActionView #:nodoc:
+  module TemplateHandlers #:nodoc:
+    def self.extended(base)
+      base.register_default_template_handler :erb, TemplateHandlers::ERB
+      base.register_template_handler :rjs, TemplateHandlers::RJS
+      base.register_template_handler :builder, TemplateHandlers::Builder
+
+      # TODO: Depreciate old template extensions
+      base.register_template_handler :rhtml, TemplateHandlers::ERB
+      base.register_template_handler :rxml, TemplateHandlers::Builder
+    end
+
+    @@template_handlers = {}
+    @@default_template_handlers = nil
+
+    # Register a class that knows how to handle template files with the given
+    # extension. This can be used to implement new template types.
+    # The constructor for the class must take the ActiveView::Base instance
+    # as a parameter, and the class must implement a +render+ method that
+    # takes the contents of the template to render as well as the Hash of
+    # local assigns available to the template. The +render+ method ought to
+    # return the rendered template as a string.
+    def register_template_handler(extension, klass)
+      @@template_handlers[extension.to_sym] = klass
+    end
+
+    def template_handler_extensions
+      @@template_handlers.keys.map(&:to_s).sort
+    end
+
+    def register_default_template_handler(extension, klass)
+      register_template_handler(extension, klass)
+      @@default_template_handlers = klass
+    end
+
+    def handler_class_for_extension(extension)
+      (extension && @@template_handlers[extension.to_sym]) || @@default_template_handlers
+    end
+  end
+end
diff --git a/actionpack/lib/action_view/template_handlers/compilable.rb b/actionpack/lib/action_view/template_handlers/compilable.rb
index 28c72172a0..1aef81ba1a 100644
--- a/actionpack/lib/action_view/template_handlers/compilable.rb
+++ b/actionpack/lib/action_view/template_handlers/compilable.rb
@@ -106,7 +106,7 @@ module ActionView
           locals_code << "#{key} = local_assigns[:#{key}]\n"
         end
 
-        "def #{render_symbol}(local_assigns)\nold_output_buffer = @output_buffer;#{locals_code}#{body}\nensure\n@output_buffer = old_output_buffer\nend"
+        "def #{render_symbol}(local_assigns)\nold_output_buffer = output_buffer;#{locals_code}#{body}\nensure\nself.output_buffer = old_output_buffer\nend"
       end
 
       # Return true if the given template was compiled for a superset of the keys in local_assigns
diff --git a/actionpack/lib/action_view/test_case.rb b/actionpack/lib/action_view/test_case.rb
index 16fedd9732..1a3c93c283 100644
--- a/actionpack/lib/action_view/test_case.rb
+++ b/actionpack/lib/action_view/test_case.rb
@@ -37,6 +37,8 @@ module ActionView
       if helper_class && !self.class.ancestors.include?(helper_class)
         self.class.send(:include, helper_class)
       end
+
+      self.output_buffer = ''
     end
 
     class TestController < ActionController::Base
@@ -48,6 +50,9 @@ module ActionView
       end
     end
 
+    protected
+      attr_accessor :output_buffer
+
     private
       def method_missing(selector, *args)
         controller = TestController.new
diff --git a/actionpack/lib/action_view/view_load_paths.rb b/actionpack/lib/action_view/view_load_paths.rb
new file mode 100644
index 0000000000..e873d96aa0
--- /dev/null
+++ b/actionpack/lib/action_view/view_load_paths.rb
@@ -0,0 +1,103 @@
+module ActionView #:nodoc:
+  class ViewLoadPaths < Array #:nodoc:
+    def self.type_cast(obj)
+      obj.is_a?(String) ? LoadPath.new(obj) : obj
+    end
+
+    class LoadPath #:nodoc:
+      attr_reader :path, :paths
+      delegate :to_s, :inspect, :to => :path
+
+      def initialize(path)
+        @path = path.freeze
+        reload!
+      end
+
+      def eql?(view_path)
+        view_path.is_a?(ViewPath) && @path == view_path.path
+      end
+
+      def hash
+        @path.hash
+      end
+
+      # Rebuild load path directory cache
+      def reload!
+        @paths = {}
+
+        files.each do |file|
+          @paths[file.path] = file
+          @paths[file.path_without_extension] ||= file
+        end
+
+        @paths.freeze
+      end
+
+      # Tries to find the extension for the template name.
+      # If it does not it exist, tries again without the format extension
+      #   find_template_file_for_partial_path('users/show') => 'html.erb'
+      #   find_template_file_for_partial_path('users/legacy') => 'rhtml'
+      def find_template_file_for_partial_path(file)
+        @paths[file.path] || @paths[file.path_without_extension] || @paths[file.path_without_format_and_extension]
+      end
+
+      private
+        # Get all the files and directories in the path
+        def files_in_path
+          Dir.glob("#{@path}/**/*/**") | Dir.glob("#{@path}/**")
+        end
+
+        # Create an array of all the files within the path
+        def files
+          files_in_path.map do |file|
+            TemplateFile.from_full_path(@path, file) unless File.directory?(file)
+          end.compact
+        end
+    end
+
+    def initialize(*args)
+      super(*args).map! { |obj| self.class.type_cast(obj) }
+    end
+
+    def reload!
+      each { |path| path.reload! }
+    end
+
+    def <<(obj)
+      super(self.class.type_cast(obj))
+    end
+
+    def push(*objs)
+      delete_paths!(objs)
+      super(*objs.map { |obj| self.class.type_cast(obj) })
+    end
+
+    def unshift(*objs)
+      delete_paths!(objs)
+      super(*objs.map { |obj| self.class.type_cast(obj) })
+    end
+
+    def template_exists?(file)
+      find_load_path_for_path(file) ? true : false
+    end
+
+    def find_load_path_for_path(file)
+      find { |path| path.paths[file.to_s] }
+    end
+
+    def find_template_file_for_path(file)
+      file = TemplateFile.from_path(file)
+      each do |path|
+        if f = path.find_template_file_for_partial_path(file)
+          return f
+        end
+      end
+      nil
+    end
+
+    private
+      def delete_paths!(paths)
+        paths.each { |p1| delete_if { |p2| p1.to_s == p2.to_s } }
+      end
+  end
+end