Merge branch 'master' of git://github.com/rails/rails

32 files changed, 855 insertions, 654 deletions

diff --git a/actionpack/lib/action_view/base.rb b/actionpack/lib/action_view/base.rb
index ffe3060404..919b1e3470 100644
--- a/actionpack/lib/action_view/base.rb
+++ b/actionpack/lib/action_view/base.rb
@@ -1,27 +1,10 @@
 require 'active_support/core_ext/module/attr_internal'
 require 'active_support/core_ext/module/delegation'
 require 'active_support/core_ext/class/attribute'
+require 'active_support/core_ext/array/wrap'
 
 module ActionView #:nodoc:
-  class ActionViewError < StandardError #:nodoc:
-  end
-
-  class MissingTemplate < ActionViewError #:nodoc:
-    attr_reader :path
-
-    def initialize(paths, path, details, partial)
-      @path = path
-      display_paths = paths.compact.map{ |p| p.to_s.inspect }.join(", ")
-      template_type = if partial
-        "partial"
-      elsif path =~ /layouts/i
-        'layout'
-      else
-        'template'
-      end
-
-      super("Missing #{template_type} #{path} with #{details.inspect} in view paths #{display_paths}")
-    end
+  class NonConcattingString < ActiveSupport::SafeBuffer
   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
@@ -176,14 +159,13 @@ module ActionView #:nodoc:
     include Helpers, Rendering, Partials, Layouts, ::ERB::Util, Context
     extend  ActiveSupport::Memoizable
 
-    ActionView.run_base_hooks(self)
-
     # Specify whether RJS responses should be wrapped in a try/catch block
     # that alert()s the caught exception (and then re-raises it).
     cattr_accessor :debug_rjs
     @@debug_rjs = false
 
     class_attribute :helpers
+    remove_method :helpers
     attr_reader :helpers
 
     class << self
@@ -191,10 +173,12 @@ module ActionView #:nodoc:
       delegate :logger, :to => 'ActionController::Base', :allow_nil => true
     end
 
+    ActionView.run_base_hooks(self)
+
     attr_accessor :base_path, :assigns, :template_extension, :lookup_context
-    attr_internal :captures, :request, :layout, :controller, :template, :config
+    attr_internal :captures, :request, :controller, :template, :config
 
-    delegate :find, :exists?, :formats, :formats=, :locale, :locale=,
+    delegate :find_template, :template_exists?, :formats, :formats=, :locale, :locale=,
              :view_paths, :view_paths=, :with_fallbacks, :update_details, :to => :lookup_context
 
     delegate :request_forgery_protection_token, :template, :params, :session, :cookies, :response, :headers,
@@ -202,42 +186,17 @@ module ActionView #:nodoc:
 
     delegate :logger, :to => :controller, :allow_nil => true
 
+    # TODO: HACK FOR RJS
+    def view_context
+      self
+    end
+
     def self.xss_safe? #:nodoc:
       true
     end
 
     def self.process_view_paths(value)
-      ActionView::PathSet.new(Array(value))
-    end
-
-    def self.for_controller(controller)
-      @views ||= {}
-
-      # TODO: Decouple this so helpers are a separate concern in AV just like
-      # they are in AC.
-      if controller.class.respond_to?(:_helper_serial)
-        klass = @views[controller.class._helper_serial] ||= Class.new(self) do
-          # Try to make stack traces clearer
-          class_eval <<-ruby_eval, __FILE__, __LINE__ + 1
-            def self.name
-              "ActionView for #{controller.class}"
-            end
-
-            def inspect
-              "#<#{self.class.name}>"
-            end
-          ruby_eval
-
-          if controller.respond_to?(:_helpers)
-            include controller._helpers
-            self.helpers = controller._helpers
-          end
-        end
-      else
-        klass = self
-      end
-
-      klass.new(controller.lookup_context, {}, controller)
+      ActionView::PathSet.new(Array.wrap(value))
     end
 
     def initialize(lookup_context = nil, assigns_for_first_render = {}, controller = nil, formats = nil) #:nodoc:
@@ -246,7 +205,7 @@ module ActionView #:nodoc:
       @helpers = self.class.helpers || Module.new
 
       @_controller   = controller
-      @_config       = ActiveSupport::InheritableOptions.new(controller.config) if controller
+      @_config       = ActiveSupport::InheritableOptions.new(controller.config) if controller && controller.respond_to?(:config)
       @_content_for  = Hash.new { |h,k| h[k] = ActiveSupport::SafeBuffer.new }
       @_virtual_path = nil
 
@@ -264,14 +223,5 @@ module ActionView #:nodoc:
       response.body_parts << part
       nil
     end
-
-    # Evaluates the local assigns and controller ivars, pushes them to the view.
-    def _evaluate_assigns_and_ivars #:nodoc:
-      if controller
-        variables = controller.instance_variable_names
-        variables -= controller.protected_instance_variables if controller.respond_to?(:protected_instance_variables)
-        variables.each { |name| instance_variable_set(name, controller.instance_variable_get(name)) }
-      end
-    end
   end
 end
diff --git a/actionpack/lib/action_view/context.rb b/actionpack/lib/action_view/context.rb
index df078a7151..61d2e702a7 100644
--- a/actionpack/lib/action_view/context.rb
+++ b/actionpack/lib/action_view/context.rb
@@ -10,8 +10,6 @@ module ActionView
   # In order to work with ActionController, a Context
   # must implement:
   #
-  # Context.for_controller[controller] Create a new ActionView instance for a
-  #   controller
   # Context#render_partial[options]
   #   - responsible for setting options[:_template]
   #   - Returns String with the rendered partial
diff --git a/actionpack/lib/action_view/helpers.rb b/actionpack/lib/action_view/helpers.rb
index e359b0bdac..a50c180f63 100644
--- a/actionpack/lib/action_view/helpers.rb
+++ b/actionpack/lib/action_view/helpers.rb
@@ -2,30 +2,32 @@ require 'active_support/benchmarkable'
 
 module ActionView #:nodoc:
   module Helpers #:nodoc:
-    autoload :ActiveModelHelper, 'action_view/helpers/active_model_helper'
-    autoload :AssetTagHelper, 'action_view/helpers/asset_tag_helper'
-    autoload :AtomFeedHelper, 'action_view/helpers/atom_feed_helper'
-    autoload :CacheHelper, 'action_view/helpers/cache_helper'
-    autoload :CaptureHelper, 'action_view/helpers/capture_helper'
-    autoload :CsrfHelper, 'action_view/helpers/csrf_helper'
-    autoload :DateHelper, 'action_view/helpers/date_helper'
-    autoload :DebugHelper, 'action_view/helpers/debug_helper'
-    autoload :DeprecatedBlockHelpers, 'action_view/helpers/deprecated_block_helpers'
-    autoload :FormHelper, 'action_view/helpers/form_helper'
-    autoload :FormOptionsHelper, 'action_view/helpers/form_options_helper'
-    autoload :FormTagHelper, 'action_view/helpers/form_tag_helper'
-    autoload :JavaScriptHelper, 'action_view/helpers/javascript_helper'
-    autoload :NumberHelper, 'action_view/helpers/number_helper'
-    autoload :PrototypeHelper, 'action_view/helpers/prototype_helper'
-    autoload :RawOutputHelper, 'action_view/helpers/raw_output_helper'
-    autoload :RecordIdentificationHelper, 'action_view/helpers/record_identification_helper'
-    autoload :RecordTagHelper, 'action_view/helpers/record_tag_helper'
-    autoload :SanitizeHelper, 'action_view/helpers/sanitize_helper'
-    autoload :ScriptaculousHelper, 'action_view/helpers/scriptaculous_helper'
-    autoload :TagHelper, 'action_view/helpers/tag_helper'
-    autoload :TextHelper, 'action_view/helpers/text_helper'
-    autoload :TranslationHelper, 'action_view/helpers/translation_helper'
-    autoload :UrlHelper, 'action_view/helpers/url_helper'
+    extend ActiveSupport::Autoload
+
+    autoload :ActiveModelHelper
+    autoload :AssetTagHelper
+    autoload :AtomFeedHelper
+    autoload :CacheHelper
+    autoload :CaptureHelper
+    autoload :CsrfHelper
+    autoload :DateHelper
+    autoload :DebugHelper
+    autoload :DeprecatedBlockHelpers
+    autoload :FormHelper
+    autoload :FormOptionsHelper
+    autoload :FormTagHelper
+    autoload :JavaScriptHelper, "action_view/helpers/javascript_helper"
+    autoload :NumberHelper
+    autoload :PrototypeHelper
+    autoload :RawOutputHelper
+    autoload :RecordIdentificationHelper
+    autoload :RecordTagHelper
+    autoload :SanitizeHelper
+    autoload :ScriptaculousHelper
+    autoload :TagHelper
+    autoload :TextHelper
+    autoload :TranslationHelper
+    autoload :UrlHelper
 
     def self.included(base)
       base.extend(ClassMethods)
diff --git a/actionpack/lib/action_view/helpers/active_model_helper.rb b/actionpack/lib/action_view/helpers/active_model_helper.rb
index 4e12cdab54..80b3d3a664 100644
--- a/actionpack/lib/action_view/helpers/active_model_helper.rb
+++ b/actionpack/lib/action_view/helpers/active_model_helper.rb
@@ -3,6 +3,7 @@ require 'action_view/helpers/form_helper'
 require 'active_support/core_ext/class/attribute_accessors'
 require 'active_support/core_ext/enumerable'
 require 'active_support/core_ext/kernel/reporting'
+require 'active_support/core_ext/object/blank'
 
 module ActionView
   ActionView.base_hook do
@@ -127,9 +128,9 @@ module ActionView
         object = convert_to_model(object)
 
         if (obj = (object.respond_to?(:errors) ? object : instance_variable_get("@#{object}"))) &&
-          (errors = obj.errors[method])
+          (errors = obj.errors[method]).presence
           content_tag("div",
-            (options[:prepend_text].html_safe << errors.first).safe_concat(options[:append_text]),
+            "#{options[:prepend_text]}#{ERB::Util.h(errors.first)}#{options[:append_text]}".html_safe,
             :class => options[:css_class]
           )
         else
@@ -295,6 +296,10 @@ module ActionView
         end
       end
 
+      def error_message
+        object.errors[@method_name]
+      end
+
       def column_type
         object.send(:column_for_attribute, @method_name).type
       end
diff --git a/actionpack/lib/action_view/helpers/asset_tag_helper.rb b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
index de3d61ebbe..02ad41719b 100644
--- a/actionpack/lib/action_view/helpers/asset_tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
@@ -3,6 +3,7 @@ require 'cgi'
 require 'action_view/helpers/url_helper'
 require 'action_view/helpers/tag_helper'
 require 'active_support/core_ext/file'
+require 'active_support/core_ext/object/blank'
 
 module ActionView
   module Helpers #:nodoc:
@@ -11,7 +12,7 @@ module ActionView
     # the assets exist before linking to them:
     #
     #   image_tag("rails.png")
-    #   # => <img alt="Rails src="/images/rails.png?1230601161" />
+    #   # => <img alt="Rails" src="/images/rails.png?1230601161" />
     #   stylesheet_link_tag("application")
     #   # => <link href="/stylesheets/application.css?1232285206" media="screen" rel="stylesheet" type="text/css" />
     #
@@ -58,7 +59,7 @@ module ActionView
     # +asset_host+ to a proc like this:
     #
     #   ActionController::Base.asset_host = Proc.new { |source|
-    #     "http://assets#{rand(2) + 1}.example.com"
+    #     "http://assets#{source.hash % 2 + 1}.example.com"
     #   }
     #   image_tag("rails.png")
     #   # => <img alt="Rails" src="http://assets0.example.com/images/rails.png?1230601161" />
@@ -66,7 +67,7 @@ module ActionView
     #   # => <link href="http://assets1.example.com/stylesheets/application.css?1232285206" media="screen" rel="stylesheet" type="text/css" />
     #
     # The example above generates "http://assets1.example.com" and
-    # "http://assets2.example.com" randomly. This option is useful for example if
+    # "http://assets2.example.com". This option is useful for example if
     # you need fewer/more than four hosts, custom host names, etc.
     #
     # As you see the proc takes a +source+ parameter. That's a string with the
@@ -242,12 +243,12 @@ module ActionView
       # == Caching multiple javascripts into one
       #
       # You can also cache multiple javascripts into one file, which requires less HTTP connections to download and can better be
-      # compressed by gzip (leading to faster transfers). Caching will only happen if ActionController::Base.perform_caching
+      # compressed by gzip (leading to faster transfers). Caching will only happen if config.perform_caching
       # is set to <tt>true</tt> (which is the case by default for the Rails production environment, but not for the development
       # environment).
       #
       # ==== Examples
-      #   javascript_include_tag :all, :cache => true # when ActionController::Base.perform_caching is false =>
+      #   javascript_include_tag :all, :cache => true # when config.perform_caching is false =>
       #     <script type="text/javascript" src="/javascripts/prototype.js"></script>
       #     <script type="text/javascript" src="/javascripts/effects.js"></script>
       #     ...
@@ -255,15 +256,15 @@ module ActionView
       #     <script type="text/javascript" src="/javascripts/shop.js"></script>
       #     <script type="text/javascript" src="/javascripts/checkout.js"></script>
       #
-      #   javascript_include_tag :all, :cache => true # when ActionController::Base.perform_caching is true =>
+      #   javascript_include_tag :all, :cache => true # when config.perform_caching is true =>
       #     <script type="text/javascript" src="/javascripts/all.js"></script>
       #
-      #   javascript_include_tag "prototype", "cart", "checkout", :cache => "shop" # when ActionController::Base.perform_caching is false =>
+      #   javascript_include_tag "prototype", "cart", "checkout", :cache => "shop" # when config.perform_caching is false =>
       #     <script type="text/javascript" src="/javascripts/prototype.js"></script>
       #     <script type="text/javascript" src="/javascripts/cart.js"></script>
       #     <script type="text/javascript" src="/javascripts/checkout.js"></script>
       #
-      #   javascript_include_tag "prototype", "cart", "checkout", :cache => "shop" # when ActionController::Base.perform_caching is true =>
+      #   javascript_include_tag "prototype", "cart", "checkout", :cache => "shop" # when config.perform_caching is true =>
       #     <script type="text/javascript" src="/javascripts/shop.js"></script>
       #
       # The <tt>:recursive</tt> option is also available for caching:
@@ -275,11 +276,11 @@ module ActionView
         cache   = concat || options.delete("cache")
         recursive = options.delete("recursive")
 
-        if concat || (ActionController::Base.perform_caching && cache)
+        if concat || (config.perform_caching && cache)
           joined_javascript_name = (cache == true ? "all" : cache) + ".js"
           joined_javascript_path = File.join(joined_javascript_name[/^#{File::SEPARATOR}/] ? config.assets_dir : config.javascripts_dir, joined_javascript_name)
 
-          unless ActionController::Base.perform_caching && File.exists?(joined_javascript_path)
+          unless config.perform_caching && File.exists?(joined_javascript_path)
             write_asset_file_contents(joined_javascript_path, compute_javascript_paths(sources, recursive))
           end
           javascript_src_tag(joined_javascript_name, options)
@@ -390,25 +391,25 @@ module ActionView
       # == Caching multiple stylesheets into one
       #
       # You can also cache multiple stylesheets into one file, which requires less HTTP connections and can better be
-      # compressed by gzip (leading to faster transfers). Caching will only happen if ActionController::Base.perform_caching
+      # compressed by gzip (leading to faster transfers). Caching will only happen if config.perform_caching
       # is set to true (which is the case by default for the Rails production environment, but not for the development
       # environment). Examples:
       #
       # ==== Examples
-      #   stylesheet_link_tag :all, :cache => true # when ActionController::Base.perform_caching is false =>
+      #   stylesheet_link_tag :all, :cache => true # when config.perform_caching is false =>
       #     <link href="/stylesheets/style1.css"  media="screen" rel="stylesheet" type="text/css" />
       #     <link href="/stylesheets/styleB.css"  media="screen" rel="stylesheet" type="text/css" />
       #     <link href="/stylesheets/styleX2.css" media="screen" rel="stylesheet" type="text/css" />
       #
-      #   stylesheet_link_tag :all, :cache => true # when ActionController::Base.perform_caching is true =>
+      #   stylesheet_link_tag :all, :cache => true # when config.perform_caching is true =>
       #     <link href="/stylesheets/all.css"  media="screen" rel="stylesheet" type="text/css" />
       #
-      #   stylesheet_link_tag "shop", "cart", "checkout", :cache => "payment" # when ActionController::Base.perform_caching is false =>
+      #   stylesheet_link_tag "shop", "cart", "checkout", :cache => "payment" # when config.perform_caching is false =>
       #     <link href="/stylesheets/shop.css"  media="screen" rel="stylesheet" type="text/css" />
       #     <link href="/stylesheets/cart.css"  media="screen" rel="stylesheet" type="text/css" />
       #     <link href="/stylesheets/checkout.css" media="screen" rel="stylesheet" type="text/css" />
       #
-      #   stylesheet_link_tag "shop", "cart", "checkout", :cache => "payment" # when ActionController::Base.perform_caching is true =>
+      #   stylesheet_link_tag "shop", "cart", "checkout", :cache => "payment" # when config.perform_caching is true =>
       #     <link href="/stylesheets/payment.css"  media="screen" rel="stylesheet" type="text/css" />
       #
       # The <tt>:recursive</tt> option is also available for caching:
@@ -426,11 +427,11 @@ module ActionView
         cache   = concat || options.delete("cache")
         recursive = options.delete("recursive")
 
-        if concat || (ActionController::Base.perform_caching && cache)
+        if concat || (config.perform_caching && cache)
           joined_stylesheet_name = (cache == true ? "all" : cache) + ".css"
           joined_stylesheet_path = File.join(joined_stylesheet_name[/^#{File::SEPARATOR}/] ? config.assets_dir : config.stylesheets_dir, joined_stylesheet_name)
 
-          unless ActionController::Base.perform_caching && File.exists?(joined_stylesheet_path)
+          unless config.perform_caching && File.exists?(joined_stylesheet_path)
             write_asset_file_contents(joined_stylesheet_path, compute_stylesheet_paths(sources, recursive))
           end
           stylesheet_tag(joined_stylesheet_name, options)
@@ -523,7 +524,7 @@ module ActionView
         options.symbolize_keys!
 
         src = options[:src] = path_to_image(source)
-        options[:alt]     ||= File.basename(src, '.*').split('.').first.to_s.capitalize
+        options[:alt]     ||= File.basename(src, '.*').capitalize
 
         if size = options.delete(:size)
           options[:width], options[:height] = size.split("x") if size =~ %r{^\d+x\d+$}
@@ -623,41 +624,37 @@ module ActionView
       @@cache_asset_timestamps = true
 
       private
+        def rewrite_extension?(source, dir, ext)
+          source_ext = File.extname(source)[1..-1]
+          ext && (source_ext.blank? || (ext != source_ext && File.exist?(File.join(config.assets_dir, dir, "#{source}.#{ext}"))))
+        end
+
+        def rewrite_host_and_protocol(source, has_request)
+          host = compute_asset_host(source)
+          if has_request && host.present? && !is_uri?(host)
+            host = "#{controller.request.protocol}#{host}"
+          end
+          "#{host}#{source}"
+        end
+
         # Add the the extension +ext+ if not present. Return full URLs otherwise untouched.
         # Prefix with <tt>/dir/</tt> if lacking a leading +/+. Account for relative URL
         # roots. Rewrite the asset path for cache-busting asset ids. Include
         # asset host, if configured, with the correct request protocol.
         def compute_public_path(source, dir, ext = nil, include_host = true)
-          has_request = controller.respond_to?(:request)
-
-          source_ext = File.extname(source)[1..-1]
-          if ext && !is_uri?(source) && (source_ext.blank? || (ext != source_ext && File.exist?(File.join(config.assets_dir, dir, "#{source}.#{ext}"))))
-            source += ".#{ext}"
-          end
+          return source if is_uri?(source)
 
-          unless is_uri?(source)
-            source = "/#{dir}/#{source}" unless source[0] == ?/
+          source += ".#{ext}" if rewrite_extension?(source, dir, ext)
+          source  = "/#{dir}/#{source}" unless source[0] == ?/
+          source  = rewrite_asset_path(source)
 
-            source = rewrite_asset_path(source)
-
-            if has_request && include_host
-              unless source =~ %r{^#{controller.config.relative_url_root}/}
-                source = "#{controller.config.relative_url_root}#{source}"
-              end
-            end
+          has_request = controller.respond_to?(:request)
+          if has_request && include_host && source !~ %r{^#{controller.config.relative_url_root}/}
+            source = "#{controller.config.relative_url_root}#{source}"
           end
+          source = rewrite_host_and_protocol(source, has_request) if include_host
 
-          if include_host && !is_uri?(source)
-            host = compute_asset_host(source)
-
-            if has_request && !host.blank? && !is_uri?(host)
-              host = "#{controller.request.protocol}#{host}"
-            end
-
-            "#{host}#{source}"
-          else
-            source
-          end
+          source
         end
 
         def is_uri?(path)
diff --git a/actionpack/lib/action_view/helpers/cache_helper.rb b/actionpack/lib/action_view/helpers/cache_helper.rb
index d5cc14b29a..a904af56bb 100644
--- a/actionpack/lib/action_view/helpers/cache_helper.rb
+++ b/actionpack/lib/action_view/helpers/cache_helper.rb
@@ -32,7 +32,28 @@ module ActionView
       #      <i>Topics listed alphabetically</i>
       #    <% end %>
       def cache(name = {}, options = nil, &block)
-        controller.fragment_for(output_buffer, name, options, &block)
+        safe_concat fragment_for(name, options, &block)
+        nil
+      end
+
+    private
+      # TODO: Create an object that has caching read/write on it
+      def fragment_for(name = {}, options = nil, &block) #:nodoc:
+        if controller.perform_caching
+          if controller.fragment_exist?(name, options)
+            controller.read_fragment(name, options)
+          else
+            # VIEW TODO: Make #capture usable outside of ERB
+            # This dance is needed because Builder can't use capture
+            pos = output_buffer.length
+            yield
+            fragment = output_buffer.slice!(pos..-1)
+            controller.write_fragment(name, fragment, options)
+          end
+        else
+          ret = yield
+          ActiveSupport::SafeBuffer.new(ret) if ret.is_a?(String)
+        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 75fc2fddeb..f0be814700 100644
--- a/actionpack/lib/action_view/helpers/capture_helper.rb
+++ b/actionpack/lib/action_view/helpers/capture_helper.rb
@@ -2,22 +2,22 @@ module ActionView
   module Helpers
     # CaptureHelper exposes methods to let you extract generated markup which
     # can be used in other parts of a template or layout file.
-    # It provides a method to capture blocks into variables through capture and 
+    # It provides a method to capture blocks into variables through capture and
     # a way to capture a block of markup for use in a layout through content_for.
     module CaptureHelper
-      # The capture method allows you to extract part of a template into a 
-      # variable. You can then use this variable anywhere in your templates or layout. 
-      # 
+      # The capture method allows you to extract part of a template into a
+      # variable. You can then use this variable anywhere in your templates or layout.
+      #
       # ==== Examples
       # The capture method can be used in ERb templates...
-      # 
+      #
       #   <% @greeting = capture do %>
       #     Welcome to my shiny new web page!  The date and time is
       #     <%= Time.now %>
       #   <% end %>
       #
       # ...and Builder (RXML) templates.
-      # 
+      #
       #   @timestamp = capture do
       #     "The current timestamp is #{Time.now}."
       #   end
@@ -32,16 +32,18 @@ module ActionView
       #
       def capture(*args)
         value = nil
-        buffer = with_output_buffer { value = yield *args }
-        buffer.presence || value
+        buffer = with_output_buffer { value = yield(*args) }
+        if string = buffer.presence || value and string.is_a?(String)
+          NonConcattingString.new(string)
+        end
       end
 
       # Calling content_for stores a block of markup in an identifier for later use.
       # You can make subsequent calls to the stored content in other templates or the layout
       # by passing the identifier as an argument to <tt>yield</tt>.
-      # 
+      #
       # ==== Examples
-      # 
+      #
       #   <% content_for :not_authorized do %>
       #     alert('You are not authorized to do that!')
       #   <% end %>
@@ -75,7 +77,7 @@ module ActionView
       #
       # Then, in another view, you could to do something like this:
       #
-      #   <%= link_to_remote 'Logout', :action => 'logout' %>
+      #   <%= link_to 'Logout', :action => 'logout', :remote => true %>
       #
       #   <% content_for :script do %>
       #     <%= javascript_include_tag :defaults %>
@@ -92,7 +94,7 @@ module ActionView
       #   <% end %>
       #
       #   <%#  Add some other content, or use a different template: %>
-      # 
+      #
       #   <% content_for :navigation do %>
       #     <li><%= link_to 'Login', :action => 'login' %></li>
       #   <% end %>
@@ -109,13 +111,13 @@ module ActionView
       # for elements that will be fragment cached.
       def content_for(name, content = nil, &block)
         content = capture(&block) if block_given?
-        return @_content_for[name] << content if content
-        @_content_for[name]
+        @_content_for[name] << content if content
+        @_content_for[name] unless content
       end
 
       # content_for? simply checks whether any content has been captured yet using content_for
       # Useful to render parts of your layout differently based on what is in your views.
-      # 
+      #
       # ==== Examples
       #
       # Perhaps you will use different css in you layout if no content_for :right_column
@@ -140,7 +142,7 @@ module ActionView
       def with_output_buffer(buf = nil) #:nodoc:
         unless buf
           buf = ActionView::OutputBuffer.new
-          buf.force_encoding(output_buffer.encoding) if buf.respond_to?(:force_encoding)
+          buf.force_encoding(output_buffer.encoding) if output_buffer && buf.respond_to?(:force_encoding)
         end
         self.output_buffer, old_buffer = buf, output_buffer
         yield
diff --git a/actionpack/lib/action_view/helpers/deprecated_block_helpers.rb b/actionpack/lib/action_view/helpers/deprecated_block_helpers.rb
deleted file mode 100644
index 3d0657e873..0000000000
--- a/actionpack/lib/action_view/helpers/deprecated_block_helpers.rb
+++ /dev/null
@@ -1,52 +0,0 @@
-module ActionView
-  module Helpers
-    module DeprecatedBlockHelpers
-      extend ActiveSupport::Concern
-
-      include ActionView::Helpers::TagHelper
-      include ActionView::Helpers::TextHelper
-      include ActionView::Helpers::JavaScriptHelper
-      include ActionView::Helpers::FormHelper
-
-      def content_tag(*, &block)
-        block_called_from_erb?(block) ? safe_concat(super) : super
-      end
-
-      def javascript_tag(*, &block)
-        block_called_from_erb?(block) ? safe_concat(super) : super
-      end
-
-      def form_for(*, &block)
-        block_called_from_erb?(block) ? safe_concat(super) : super
-      end
-
-      def form_tag(*, &block)
-        block_called_from_erb?(block) ? safe_concat(super) : super
-      end
-
-      def fields_for(*, &block)
-        block_called_from_erb?(block) ? safe_concat(super) : super
-      end
-
-      def field_set_tag(*, &block)
-        block_called_from_erb?(block) ? safe_concat(super) : super
-      end
-
-      BLOCK_CALLED_FROM_ERB = 'defined? __in_erb_template'
-
-      if RUBY_VERSION < '1.9.0'
-        # Check whether we're called from an erb template.
-        # We'd return a string in any other case, but erb <%= ... %>
-        # can't take an <% end %> later on, so we have to use <% ... %>
-        # and implicitly concat.
-        def block_called_from_erb?(block)
-          block && eval(BLOCK_CALLED_FROM_ERB, block)
-        end
-      else
-        def block_called_from_erb?(block)
-          block && eval(BLOCK_CALLED_FROM_ERB, block.binding)
-        end
-      end
-    end
-  end
-end
\ No newline at end of file
diff --git a/actionpack/lib/action_view/helpers/form_helper.rb b/actionpack/lib/action_view/helpers/form_helper.rb
index 48df26efaa..2ba5339b7d 100644
--- a/actionpack/lib/action_view/helpers/form_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_helper.rb
@@ -28,7 +28,7 @@ module ActionView
     #
     #     # Note: a @person variable will have been created in the controller.
     #     # For example: @person = Person.new
-    #     <% form_for :person, @person, :url => { :action => "create" } do |f| %>
+    #     <%= form_for :person, @person, :url => { :action => "create" } do |f| %>
     #       <%= f.text_field :first_name %>
     #       <%= f.text_field :last_name %>
     #       <%= submit_tag 'Create' %>
@@ -44,7 +44,7 @@ module ActionView
     #
     # If you are using a partial for your form fields, you can use this shortcut:
     #
-    #     <% form_for :person, @person, :url => { :action => "create" } do |f| %>
+    #     <%= form_for :person, @person, :url => { :action => "create" } do |f| %>
     #       <%= render :partial => f %>
     #       <%= submit_tag 'Create' %>
     #     <% end %>
@@ -102,7 +102,7 @@ module ActionView
       # Rails provides succinct resource-oriented form generation with +form_for+
       # like this:
       #
-      #   <% form_for @offer do |f| %>
+      #   <%= form_for @offer do |f| %>
       #     <%= f.label :version, 'Version' %>:
       #     <%= f.text_field :version %><br />
       #     <%= f.label :author, 'Author' %>:
@@ -119,7 +119,7 @@ module ActionView
       # The generic way to call +form_for+ yields a form builder around a
       # model:
       #
-      #   <% form_for :person, :url => { :action => "update" } do |f| %>
+      #   <%= form_for :person, :url => { :action => "update" } do |f| %>
       #     <%= f.error_messages %>
       #     First name: <%= f.text_field :first_name %><br />
       #     Last name : <%= f.text_field :last_name %><br />
@@ -143,7 +143,7 @@ module ActionView
       # If the instance variable is not <tt>@person</tt> you can pass the actual
       # record as the second argument:
       #
-      #   <% form_for :person, person, :url => { :action => "update" } do |f| %>
+      #   <%= form_for :person, person, :url => { :action => "update" } do |f| %>
       #     ...
       #   <% end %>
       #
@@ -175,7 +175,7 @@ module ActionView
       # possible to use both the stand-alone FormHelper methods and methods
       # from FormTagHelper. For example:
       #
-      #   <% form_for :person, @person, :url => { :action => "update" } do |f| %>
+      #   <%= form_for :person, @person, :url => { :action => "update" } do |f| %>
       #     First name: <%= f.text_field :first_name %>
       #     Last name : <%= f.text_field :last_name %>
       #     Biography : <%= text_area :person, :biography %>
@@ -195,37 +195,37 @@ module ActionView
       #
       # For example, if <tt>@post</tt> is an existing record you want to edit
       #
-      #   <% form_for @post do |f| %>
+      #   <%= form_for @post do |f| %>
       #     ...
       #   <% end %>
       #
       # is equivalent to something like:
       #
-      #   <% form_for :post, @post, :url => post_path(@post), :html => { :method => :put, :class => "edit_post", :id => "edit_post_45" } do |f| %>
+      #   <%= form_for :post, @post, :url => post_path(@post), :html => { :method => :put, :class => "edit_post", :id => "edit_post_45" } do |f| %>
       #     ...
       #   <% end %>
       #
       # And for new records
       #
-      #   <% form_for(Post.new) do |f| %>
+      #   <%= form_for(Post.new) do |f| %>
       #     ...
       #   <% end %>
       #
       # expands to
       #
-      #   <% form_for :post, Post.new, :url => posts_path, :html => { :class => "new_post", :id => "new_post" } do |f| %>
+      #   <%= form_for :post, Post.new, :url => posts_path, :html => { :class => "new_post", :id => "new_post" } do |f| %>
       #     ...
       #   <% end %>
       #
       # You can also overwrite the individual conventions, like this:
       #
-      #   <% form_for(@post, :url => super_post_path(@post)) do |f| %>
+      #   <%= form_for(@post, :url => super_post_path(@post)) do |f| %>
       #     ...
       #   <% end %>
       #
       # And for namespaced routes, like +admin_post_url+:
       #
-      #   <% form_for([:admin, @post]) do |f| %>
+      #   <%= form_for([:admin, @post]) do |f| %>
       #    ...
       #   <% end %>
       #
@@ -243,7 +243,7 @@ module ActionView
       #
       # Example:
       #
-      #   <% form_for(:post, @post, :remote => true, :html => { :id => 'create-post', :method => :put }) do |f| %>
+      #   <%= form_for(:post, @post, :remote => true, :html => { :id => 'create-post', :method => :put }) do |f| %>
       #     ...
       #   <% end %>
       #
@@ -263,7 +263,7 @@ module ActionView
       # custom builder. For example, let's say you made a helper to
       # automatically add labels to form inputs.
       #
-      #   <% form_for :person, @person, :url => { :action => "update" }, :builder => LabellingFormBuilder do |f| %>
+      #   <%= form_for :person, @person, :url => { :action => "update" }, :builder => LabellingFormBuilder do |f| %>
       #     <%= f.text_field :first_name %>
       #     <%= f.text_field :last_name %>
       #     <%= text_area :person, :biography %>
@@ -340,11 +340,11 @@ module ActionView
       #
       # === Generic Examples
       #
-      #   <% form_for @person, :url => { :action => "update" } do |person_form| %>
+      #   <%= form_for @person, :url => { :action => "update" } do |person_form| %>
       #     First name: <%= person_form.text_field :first_name %>
       #     Last name : <%= person_form.text_field :last_name %>
       #
-      #     <% fields_for @person.permission do |permission_fields| %>
+      #     <%= fields_for @person.permission do |permission_fields| %>
       #       Admin?  : <%= permission_fields.check_box :admin %>
       #     <% end %>
       #   <% end %>
@@ -352,13 +352,13 @@ module ActionView
       # ...or if you have an object that needs to be represented as a different
       # parameter, like a Client that acts as a Person:
       #
-      #   <% fields_for :person, @client do |permission_fields| %>
+      #   <%= fields_for :person, @client do |permission_fields| %>
       #     Admin?: <%= permission_fields.check_box :admin %>
       #   <% end %>
       #
       # ...or if you don't have an object, just a name of the parameter:
       #
-      #   <% fields_for :person do |permission_fields| %>
+      #   <%= fields_for :person do |permission_fields| %>
       #     Admin?: <%= permission_fields.check_box :admin %>
       #   <% end %>
       #
@@ -402,9 +402,9 @@ module ActionView
       #
       # This model can now be used with a nested fields_for, like so:
       #
-      #   <% form_for @person, :url => { :action => "update" } do |person_form| %>
+      #   <%= form_for @person, :url => { :action => "update" } do |person_form| %>
       #     ...
-      #     <% person_form.fields_for :address do |address_fields| %>
+      #     <%= person_form.fields_for :address do |address_fields| %>
       #       Street  : <%= address_fields.text_field :street %>
       #       Zip code: <%= address_fields.text_field :zip_code %>
       #     <% end %>
@@ -427,15 +427,15 @@ module ActionView
       #     accepts_nested_attributes_for :address, :allow_destroy => true
       #   end
       #
-      # Now, when you use a form element with the <tt>_delete</tt> parameter,
+      # Now, when you use a form element with the <tt>_destroy</tt> parameter,
       # with a value that evaluates to +true+, you will destroy the associated
       # model (eg. 1, '1', true, or 'true'):
       #
-      #   <% form_for @person, :url => { :action => "update" } do |person_form| %>
+      #   <%= form_for @person, :url => { :action => "update" } do |person_form| %>
       #     ...
-      #     <% person_form.fields_for :address do |address_fields| %>
+      #     <%= person_form.fields_for :address do |address_fields| %>
       #       ...
-      #       Delete: <%= address_fields.check_box :_delete %>
+      #       Delete: <%= address_fields.check_box :_destroy %>
       #     <% end %>
       #   <% end %>
       #
@@ -459,9 +459,9 @@ module ActionView
       # the nested fields_for call will be repeated for each instance in the
       # collection:
       #
-      #   <% form_for @person, :url => { :action => "update" } do |person_form| %>
+      #   <%= form_for @person, :url => { :action => "update" } do |person_form| %>
       #     ...
-      #     <% person_form.fields_for :projects do |project_fields| %>
+      #     <%= person_form.fields_for :projects do |project_fields| %>
       #       <% if project_fields.object.active? %>
       #         Name: <%= project_fields.text_field :name %>
       #       <% end %>
@@ -470,11 +470,11 @@ module ActionView
       #
       # It's also possible to specify the instance to be used:
       #
-      #   <% form_for @person, :url => { :action => "update" } do |person_form| %>
+      #   <%= form_for @person, :url => { :action => "update" } do |person_form| %>
       #     ...
       #     <% @person.projects.each do |project| %>
       #       <% if project.active? %>
-      #         <% person_form.fields_for :projects, project do |project_fields| %>
+      #         <%= person_form.fields_for :projects, project do |project_fields| %>
       #           Name: <%= project_fields.text_field :name %>
       #         <% end %>
       #       <% end %>
@@ -483,9 +483,9 @@ module ActionView
       #
       # Or a collection to be used:
       #
-      #   <% form_for @person, :url => { :action => "update" } do |person_form| %>
+      #   <%= form_for @person, :url => { :action => "update" } do |person_form| %>
       #     ...
-      #     <% person_form.fields_for :projects, @active_projects do |project_fields| %>
+      #     <%= person_form.fields_for :projects, @active_projects do |project_fields| %>
       #       Name: <%= project_fields.text_field :name %>
       #     <% end %>
       #   <% end %>
@@ -508,14 +508,14 @@ module ActionView
       #   end
       #
       # This will allow you to specify which models to destroy in the
-      # attributes hash by adding a form element for the <tt>_delete</tt>
+      # attributes hash by adding a form element for the <tt>_destroy</tt>
       # parameter with a value that evaluates to +true+
       # (eg. 1, '1', true, or 'true'):
       #
-      #   <% form_for @person, :url => { :action => "update" } do |person_form| %>
+      #   <%= form_for @person, :url => { :action => "update" } do |person_form| %>
       #     ...
-      #     <% person_form.fields_for :projects do |project_fields| %>
-      #       Delete: <%= project_fields.check_box :_delete %>
+      #     <%= person_form.fields_for :projects do |project_fields| %>
+      #       Delete: <%= project_fields.check_box :_destroy %>
       #     <% end %>
       #   <% end %>
       def fields_for(record_or_name_or_array, *args, &block)
@@ -725,7 +725,7 @@ module ActionView
       # Unfortunately that workaround does not work when the check box goes
       # within an array-like parameter, as in
       #
-      #   <% fields_for "project[invoice_attributes][]", invoice, :index => nil do |form| %>
+      #   <%= fields_for "project[invoice_attributes][]", invoice, :index => nil do |form| %>
       #     <%= form.check_box :paid %>
       #     ...
       #   <% end %>
@@ -1014,7 +1014,7 @@ module ActionView
     class FormBuilder #:nodoc:
       # The methods which wrap a form helper call.
       class_inheritable_accessor :field_helpers
-      self.field_helpers = (FormHelper.instance_methods - ['form_for'])
+      self.field_helpers = (FormHelper.instance_method_names - ['form_for'])
 
       attr_accessor :object_name, :object, :options
 
@@ -1040,7 +1040,7 @@ module ActionView
       end
 
       (field_helpers - %w(label check_box radio_button fields_for hidden_field)).each do |selector|
-        src = <<-end_src
+        src, file, line = <<-end_src, __FILE__, __LINE__ + 1
           def #{selector}(method, options = {})  # def text_field(method, options = {})
             @template.send(                      #   @template.send(
               #{selector.inspect},               #     "text_field",
@@ -1049,7 +1049,7 @@ module ActionView
               objectify_options(options))        #     objectify_options(options))
           end                                    # end
         end_src
-        class_eval src, __FILE__, __LINE__
+        class_eval src, file, line
       end
 
       def fields_for(record_or_name_or_array, *args, &block)
@@ -1115,7 +1115,7 @@ module ActionView
       # Add the submit button for the given form. When no value is given, it checks
       # if the object is a new resource or not to create the proper label:
       #
-      #   <% form_for @post do |f| %>
+      #   <%= form_for @post do |f| %>
       #     <%= f.submit %>
       #   <% end %>
       # 
diff --git a/actionpack/lib/action_view/helpers/form_options_helper.rb b/actionpack/lib/action_view/helpers/form_options_helper.rb
index 7039ecd233..4c523d4b20 100644
--- a/actionpack/lib/action_view/helpers/form_options_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_options_helper.rb
@@ -151,7 +151,7 @@ module ActionView
       #   end
       #
       # Sample usage (selecting the associated Author for an instance of Post, <tt>@post</tt>):
-      #   collection_select(:post, :author_id, Author.all, :id, :name_with_initial, {:prompt => true})
+      #   collection_select(:post, :author_id, Author.all, :id, :name_with_initial, :prompt => true)
       #
       # If <tt>@post.author_id</tt> is already <tt>1</tt>, this would return:
       #   <select name="post[author_id]">
diff --git a/actionpack/lib/action_view/helpers/form_tag_helper.rb b/actionpack/lib/action_view/helpers/form_tag_helper.rb
index 573733ffea..07694f5ebb 100644
--- a/actionpack/lib/action_view/helpers/form_tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_tag_helper.rb
@@ -37,12 +37,12 @@ module ActionView
       #   form_tag('/upload', :multipart => true)
       #   # => <form action="/upload" method="post" enctype="multipart/form-data">
       #
-      #   <% form_tag('/posts')do -%>
+      #   <%= form_tag('/posts')do -%>
       #     <div><%= submit_tag 'Save' %></div>
       #   <% end -%>
       #   # => <form action="/posts" method="post"><div><input type="submit" name="submit" value="Save" /></div></form>
       # 
-      #  <% form_tag('/posts', :remote => true) %>
+      #  <%= form_tag('/posts', :remote => true) %>
       #   # => <form action="/posts" method="post" data-remote="true">
       #   
       def form_tag(url_for_options = {}, options = {}, *parameters_for_url, &block)
@@ -430,17 +430,17 @@ module ActionView
       # <tt>options</tt> accept the same values as tag.
       #
       # ==== Examples
-      #   <% field_set_tag do %>
+      #   <%= field_set_tag do %>
       #     <p><%= text_field_tag 'name' %></p>
       #   <% end %>
       #   # => <fieldset><p><input id="name" name="name" type="text" /></p></fieldset>
       #
-      #   <% field_set_tag 'Your details' do %>
+      #   <%= field_set_tag 'Your details' do %>
       #     <p><%= text_field_tag 'name' %></p>
       #   <% end %>
       #   # => <fieldset><legend>Your details</legend><p><input id="name" name="name" type="text" /></p></fieldset>
       #
-      #   <% field_set_tag nil, :class => 'format' do %>
+      #   <%= field_set_tag nil, :class => 'format' do %>
       #     <p><%= text_field_tag 'name' %></p>
       #   <% end %>
       #   # => <fieldset class="format"><p><input id="name" name="name" type="text" /></p></fieldset>
diff --git a/actionpack/lib/action_view/helpers/javascript_helper.rb b/actionpack/lib/action_view/helpers/javascript_helper.rb
index 8dab3094dd..b0a7718f22 100644
--- a/actionpack/lib/action_view/helpers/javascript_helper.rb
+++ b/actionpack/lib/action_view/helpers/javascript_helper.rb
@@ -1,5 +1,4 @@
 require 'action_view/helpers/tag_helper'
-require 'action_view/helpers/prototype_helper'
 
 module ActionView
   module Helpers
@@ -71,7 +70,7 @@ module ActionView
       #
       # Instead of passing the content as an argument, you can also use a block
       # in which case, you pass your +html_options+ as the first parameter.
-      #   <% javascript_tag :defer => 'defer' do -%>
+      #   <%= javascript_tag :defer => 'defer' do -%>
       #     alert('All is good')
       #   <% end -%>
       def javascript_tag(content_or_options_with_block = nil, html_options = {}, &block)
@@ -89,6 +88,93 @@ module ActionView
       def javascript_cdata_section(content) #:nodoc:
         "\n//#{cdata_section("\n#{content}\n//")}\n".html_safe
       end
+
+      # Returns a button with the given +name+ text that'll trigger a JavaScript +function+ using the
+      # onclick handler.
+      #
+      # The first argument +name+ is used as the button's value or display text.
+      #
+      # The next arguments are optional and may include the javascript function definition and a hash of html_options.
+      #
+      # The +function+ argument can be omitted in favor of an +update_page+
+      # block, which evaluates to a string when the template is rendered
+      # (instead of making an Ajax request first).
+      #
+      # The +html_options+ will accept a hash of html attributes for the link tag. Some examples are :class => "nav_button", :id => "articles_nav_button"
+      #
+      # Note: if you choose to specify the javascript function in a block, but would like to pass html_options, set the +function+ parameter to nil
+      #
+      # Examples:
+      #   button_to_function "Greeting", "alert('Hello world!')"
+      #   button_to_function "Delete", "if (confirm('Really?')) do_delete()"
+      #   button_to_function "Details" do |page|
+      #     page[:details].visual_effect :toggle_slide
+      #   end
+      #   button_to_function "Details", :class => "details_button" do |page|
+      #     page[:details].visual_effect :toggle_slide
+      #   end
+      def button_to_function(name, *args, &block)
+        html_options = args.extract_options!.symbolize_keys
+
+        function = block_given? ? update_page(&block) : args[0] || ''
+        onclick = "#{"#{html_options[:onclick]}; " if html_options[:onclick]}#{function};"
+
+        tag(:input, html_options.merge(:type => 'button', :value => name, :onclick => onclick))
+      end
+
+      # Returns a link of the given +name+ that will trigger a JavaScript +function+ using the
+      # onclick handler and return false after the fact.
+      #
+      # The first argument +name+ is used as the link text.
+      #
+      # The next arguments are optional and may include the javascript function definition and a hash of html_options.
+      #
+      # The +function+ argument can be omitted in favor of an +update_page+
+      # block, which evaluates to a string when the template is rendered
+      # (instead of making an Ajax request first).
+      #
+      # The +html_options+ will accept a hash of html attributes for the link tag. Some examples are :class => "nav_button", :id => "articles_nav_button"
+      #
+      # Note: if you choose to specify the javascript function in a block, but would like to pass html_options, set the +function+ parameter to nil
+      #
+      #
+      # Examples:
+      #   link_to_function "Greeting", "alert('Hello world!')"
+      #     Produces:
+      #       <a onclick="alert('Hello world!'); return false;" href="#">Greeting</a>
+      #
+      #   link_to_function(image_tag("delete"), "if (confirm('Really?')) do_delete()")
+      #     Produces:
+      #       <a onclick="if (confirm('Really?')) do_delete(); return false;" href="#">
+      #         <img src="/images/delete.png?" alt="Delete"/>
+      #       </a>
+      #
+      #   link_to_function("Show me more", nil, :id => "more_link") do |page|
+      #     page[:details].visual_effect  :toggle_blind
+      #     page[:more_link].replace_html "Show me less"
+      #   end
+      #     Produces:
+      #       <a href="#" id="more_link" onclick="try {
+      #         $(&quot;details&quot;).visualEffect(&quot;toggle_blind&quot;);
+      #         $(&quot;more_link&quot;).update(&quot;Show me less&quot;);
+      #       }
+      #       catch (e) {
+      #         alert('RJS error:\n\n' + e.toString());
+      #         alert('$(\&quot;details\&quot;).visualEffect(\&quot;toggle_blind\&quot;);
+      #         \n$(\&quot;more_link\&quot;).update(\&quot;Show me less\&quot;);');
+      #         throw e
+      #       };
+      #       return false;">Show me more</a>
+      #
+      def link_to_function(name, *args, &block)
+        html_options = args.extract_options!.symbolize_keys
+
+        function = block_given? ? update_page(&block) : args[0] || ''
+        onclick = "#{"#{html_options[:onclick]}; " if html_options[:onclick]}#{function}; return false;"
+        href = html_options[:href] || '#'
+
+        content_tag(:a, name, html_options.merge(:href => href, :onclick => onclick))
+      end
     end
   end
 end
diff --git a/actionpack/lib/action_view/helpers/number_helper.rb b/actionpack/lib/action_view/helpers/number_helper.rb
index 46e41bc406..719b64b940 100644
--- a/actionpack/lib/action_view/helpers/number_helper.rb
+++ b/actionpack/lib/action_view/helpers/number_helper.rb
@@ -3,10 +3,24 @@ require 'active_support/core_ext/float/rounding'
 
 module ActionView
   module Helpers #:nodoc:
+
     # Provides methods for converting numbers into formatted strings.
     # Methods are provided for phone numbers, currency, percentage,
-    # precision, positional notation, and file size.
+    # precision, positional notation, file size and pretty printing.
+    #
+    # Most methods expect a +number+ argument, and will return it
+    # unchanged if can't be converted into a valid number.
     module NumberHelper
+
+      # Raised when argument +number+ param given to the helpers is invalid and
+      # the option :raise is set to  +true+.
+      class InvalidNumberError < StandardError
+        attr_accessor :number
+        def initialize(number)
+          @number = number
+        end
+      end
+
       # Formats a +number+ into a US phone number (e.g., (555) 123-9876). You can customize the format
       # in the +options+ hash.
       #
@@ -30,6 +44,17 @@ module ActionView
       def number_to_phone(number, options = {})
         return nil if number.nil?
 
+        begin
+          Float(number)
+          is_number_html_safe = true
+        rescue ArgumentError, TypeError
+          if options[:raise]
+            raise InvalidNumberError, number
+          else
+            is_number_html_safe = number.to_s.html_safe?
+          end
+        end
+
         number       = number.to_s.strip
         options      = options.symbolize_keys
         area_code    = options[:area_code] || nil
@@ -46,7 +71,7 @@ module ActionView
           number.starts_with?('-') ? number.slice!(1..-1) : number
         end
         str << " x #{extension}" unless extension.blank?
-        str
+        is_number_html_safe ? str.html_safe : str
       end
 
       # Formats a +number+ into a currency string (e.g., $13.65). You can customize the format
@@ -72,38 +97,42 @@ module ActionView
       #  number_to_currency(1234567890.50, :unit => "&pound;", :separator => ",", :delimiter => "", :format => "%n %u")
       #  # => 1234567890,50 &pound;
       def number_to_currency(number, options = {})
+        return nil if number.nil?
+
         options.symbolize_keys!
 
-        defaults  = I18n.translate(:'number.format', :locale => options[:locale], :raise => true) rescue {}
-        currency  = I18n.translate(:'number.currency.format', :locale => options[:locale], :raise => true) rescue {}
+        defaults  = I18n.translate(:'number.format', :locale => options[:locale], :default => {})
+        currency  = I18n.translate(:'number.currency.format', :locale => options[:locale], :default => {})
         defaults  = defaults.merge(currency)
 
-        precision = options[:precision] || defaults[:precision]
-        unit      = options[:unit]      || defaults[:unit]
-        separator = options[:separator] || defaults[:separator]
-        delimiter = options[:delimiter] || defaults[:delimiter]
-        format    = options[:format]    || defaults[:format]
-        separator = '' if precision == 0
+        options = options.reverse_merge(defaults)
 
-        value = number_with_precision(number,
-          :precision => precision,
-          :delimiter => delimiter,
-          :separator => separator)
+        unit      = options.delete(:unit)
+        format    = options.delete(:format)
 
-        if value
+        begin
+          value = number_with_precision(number, options.merge(:raise => true))
           format.gsub(/%n/, value).gsub(/%u/, unit).html_safe
-        else
-          number
+        rescue InvalidNumberError => e
+          if options[:raise]
+            raise
+          else
+            formatted_number = format.gsub(/%n/, e.number).gsub(/%u/, unit)
+            e.number.to_s.html_safe? ? formatted_number.html_safe : formatted_number
+          end
         end
+
       end
 
       # Formats a +number+ as a percentage string (e.g., 65%). You can customize the
       # format in the +options+ hash.
       #
       # ==== Options
-      # * <tt>:precision</tt>  - Sets the level of precision (defaults to 3).
-      # * <tt>:separator</tt>  - Sets the separator between the units (defaults to ".").
+      # * <tt>:precision</tt>  - Sets the precision of the number (defaults to 3).
+      # * <tt>:significant</tt>  - If +true+, precision will be the # of significant_digits. If +false+, the # of fractional digits (defaults to +false+)
+      # * <tt>:separator</tt>  - Sets the separator between the fractional and integer digits (defaults to ".").
       # * <tt>:delimiter</tt>  - Sets the thousands delimiter (defaults to "").
+      # * <tt>:strip_insignificant_zeros</tt>  - If +true+ removes insignificant zeros after the decimal separator (defaults to +false+)
       #
       # ==== Examples
       #  number_to_percentage(100)                                        # => 100.000%
@@ -111,21 +140,25 @@ module ActionView
       #  number_to_percentage(1000, :delimiter => '.', :separator => ',') # => 1.000,000%
       #  number_to_percentage(302.24398923423, :precision => 5)           # => 302.24399%
       def number_to_percentage(number, options = {})
+        return nil if number.nil?
+
         options.symbolize_keys!
 
-        defaults   = I18n.translate(:'number.format', :locale => options[:locale], :raise => true) rescue {}
-        percentage = I18n.translate(:'number.percentage.format', :locale => options[:locale], :raise => true) rescue {}
+        defaults   = I18n.translate(:'number.format', :locale => options[:locale], :default => {})
+        percentage = I18n.translate(:'number.percentage.format', :locale => options[:locale], :default => {})
         defaults  = defaults.merge(percentage)
 
-        precision = options[:precision] || defaults[:precision]
-        separator = options[:separator] || defaults[:separator]
-        delimiter = options[:delimiter] || defaults[:delimiter]
+        options = options.reverse_merge(defaults)
 
-        value = number_with_precision(number,
-          :precision => precision,
-          :separator => separator,
-          :delimiter => delimiter)
-        value ? value + "%" : number
+        begin
+          "#{number_with_precision(number, options.merge(:raise => true))}%".html_safe
+        rescue InvalidNumberError => e
+          if options[:raise]
+            raise
+          else
+            e.number.to_s.html_safe? ? "#{e.number}%".html_safe : "#{e.number}%"
+          end
+        end
       end
 
       # Formats a +number+ with grouped thousands using +delimiter+ (e.g., 12,324). You can
@@ -133,7 +166,7 @@ module ActionView
       #
       # ==== Options
       # * <tt>:delimiter</tt>  - Sets the thousands delimiter (defaults to ",").
-      # * <tt>:separator</tt>  - Sets the separator between the units (defaults to ".").
+      # * <tt>:separator</tt>  - Sets the separator between the fractional and integer digits (defaults to ".").
       #
       # ==== Examples
       #  number_with_delimiter(12345678)                        # => 12,345,678
@@ -146,148 +179,186 @@ module ActionView
       # You can still use <tt>number_with_delimiter</tt> with the old API that accepts the
       # +delimiter+ as its optional second and the +separator+ as its
       # optional third parameter:
-      #  number_with_delimiter(12345678, " ")                     # => 12 345.678
+      #  number_with_delimiter(12345678, " ")                     # => 12 345 678
       #  number_with_delimiter(12345678.05, ".", ",")             # => 12.345.678,05
       def number_with_delimiter(number, *args)
         options = args.extract_options!
         options.symbolize_keys!
 
-        defaults = I18n.translate(:'number.format', :locale => options[:locale], :raise => true) rescue {}
+        begin
+          Float(number)
+        rescue ArgumentError, TypeError
+          if options[:raise]
+            raise InvalidNumberError, number
+          else
+            return number
+          end
+        end
+
+        defaults = I18n.translate(:'number.format', :locale => options[:locale], :default => {})
 
         unless args.empty?
           ActiveSupport::Deprecation.warn('number_with_delimiter takes an option hash ' +
             'instead of separate delimiter and precision arguments.', caller)
-          delimiter = args[0] || defaults[:delimiter]
-          separator = args[1] || defaults[:separator]
+          options[:delimiter] ||= args[0] if args[0]
+          options[:separator] ||= args[1] if args[1]
         end
 
-        delimiter ||= (options[:delimiter] || defaults[:delimiter])
-        separator ||= (options[:separator] || defaults[:separator])
+        options = options.reverse_merge(defaults)
 
         parts = number.to_s.split('.')
-        if parts[0]
-          parts[0].gsub!(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1#{delimiter}")
-          parts.join(separator)
-        else
-          number
-        end
+        parts[0].gsub!(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1#{options[:delimiter]}")
+        parts.join(options[:separator]).html_safe
+
       end
 
-      # Formats a +number+ with the specified level of <tt>:precision</tt> (e.g., 112.32 has a precision of 2).
+      # Formats a +number+ with the specified level of <tt>:precision</tt> (e.g., 112.32 has a precision
+      # of 2 if +:significant+ is +false+, and 5 if +:significant+ is +true+).
       # You can customize the format in the +options+ hash.
       #
       # ==== Options
-      # * <tt>:precision</tt>  - Sets the level of precision (defaults to 3).
-      # * <tt>:separator</tt>  - Sets the separator between the units (defaults to ".").
+      # * <tt>:precision</tt>  - Sets the precision of the number (defaults to 3).
+      # * <tt>:significant</tt>  - If +true+, precision will be the # of significant_digits. If +false+, the # of fractional digits (defaults to +false+)
+      # * <tt>:separator</tt>  - Sets the separator between the fractional and integer digits (defaults to ".").
       # * <tt>:delimiter</tt>  - Sets the thousands delimiter (defaults to "").
+      # * <tt>:strip_insignificant_zeros</tt>  - If +true+ removes insignificant zeros after the decimal separator (defaults to +false+)
       #
       # ==== Examples
-      #  number_with_precision(111.2345)                    # => 111.235
-      #  number_with_precision(111.2345, :precision => 2)   # => 111.23
-      #  number_with_precision(13, :precision => 5)         # => 13.00000
-      #  number_with_precision(389.32314, :precision => 0)  # => 389
+      #  number_with_precision(111.2345)                                            # => 111.235
+      #  number_with_precision(111.2345, :precision => 2)                           # => 111.23
+      #  number_with_precision(13, :precision => 5)                                 # => 13.00000
+      #  number_with_precision(389.32314, :precision => 0)                          # => 389
+      #  number_with_precision(111.2345, :significant => true)                      # => 111
+      #  number_with_precision(111.2345, :precision => 1, :significant => true)     # => 100
+      #  number_with_precision(13, :precision => 5, :significant => true)           # => 13.000
+      #  number_with_precision(13, :precision => 5, :significant => true, strip_insignificant_zeros => true)
+      #  # => 13
+      #  number_with_precision(389.32314, :precision => 4, :significant => true)    # => 389.3
       #  number_with_precision(1111.2345, :precision => 2, :separator => ',', :delimiter => '.')
       #  # => 1.111,23
       #
       # You can still use <tt>number_with_precision</tt> with the old API that accepts the
       # +precision+ as its optional second parameter:
-      #   number_with_precision(number_with_precision(111.2345, 2)   # => 111.23
+      #   number_with_precision(111.2345, 2)   # => 111.23
       def number_with_precision(number, *args)
+
         options = args.extract_options!
         options.symbolize_keys!
 
-        defaults           = I18n.translate(:'number.format', :locale => options[:locale], :raise => true) rescue {}
-        precision_defaults = I18n.translate(:'number.precision.format', :locale => options[:locale],
-                                                                        :raise => true) rescue {}
+        number = begin
+          Float(number)
+        rescue ArgumentError, TypeError
+          if options[:raise]
+            raise InvalidNumberError, number
+          else
+            return number
+          end
+        end
+
+        defaults           = I18n.translate(:'number.format', :locale => options[:locale], :default => {})
+        precision_defaults = I18n.translate(:'number.precision.format', :locale => options[:locale], :default => {})
         defaults           = defaults.merge(precision_defaults)
 
+        #Backwards compatibility
         unless args.empty?
           ActiveSupport::Deprecation.warn('number_with_precision takes an option hash ' +
             'instead of a separate precision argument.', caller)
-          precision = args[0] || defaults[:precision]
+          options[:precision] ||= args[0] if args[0]
         end
 
-        precision ||= (options[:precision] || defaults[:precision])
-        separator ||= (options[:separator] || defaults[:separator])
-        delimiter ||= (options[:delimiter] || defaults[:delimiter])
+        options = options.reverse_merge(defaults)  # Allow the user to unset default values: Eg.: :significant => false
+        precision = options.delete :precision
+        significant = options.delete :significant
+        strip_insignificant_zeros = options.delete :strip_insignificant_zeros
 
-        begin
-          value = Float(number)
-        rescue ArgumentError, TypeError
-          value = nil
+        if significant and precision > 0
+          digits = (Math.log10(number) + 1).floor
+          rounded_number = BigDecimal.new((number / 10 ** (digits - precision)).to_s).round.to_f * 10 ** (digits - precision)
+          precision = precision - digits
+          precision = precision > 0 ? precision : 0  #don't let it be negative
+        else
+          rounded_number = BigDecimal.new((number * (10 ** precision)).to_s).round.to_f / 10 ** precision
         end
-
-        if value
-          rounded_number = BigDecimal.new((Float(number) * (10 ** precision)).to_s).round.to_f / 10 ** precision
-          number_with_delimiter("%01.#{precision}f" % rounded_number,
-            :separator => separator,
-            :delimiter => delimiter)
+        formatted_number = number_with_delimiter("%01.#{precision}f" % rounded_number, options)
+        if strip_insignificant_zeros
+          escaped_separator = Regexp.escape(options[:separator])
+          formatted_number.sub(/(#{escaped_separator})(\d*[1-9])?0+\z/, '\1\2').sub(/#{escaped_separator}\z/, '').html_safe
         else
-          number
+          formatted_number
         end
+
       end
 
       STORAGE_UNITS = [:byte, :kb, :mb, :gb, :tb].freeze
 
-      # Formats the bytes in +size+ into a more understandable representation
+      # Formats the bytes in +number+ into a more understandable representation
       # (e.g., giving it 1500 yields 1.5 KB). This method is useful for
-      # reporting file sizes to users. This method returns nil if
-      # +size+ cannot be converted into a number. You can customize the
+      # reporting file sizes to users. You can customize the
       # format in the +options+ hash.
       #
+      # See <tt>number_to_human</tt> if you want to pretty-print a generic number.
+      #
       # ==== Options
-      # * <tt>:precision</tt>  - Sets the level of precision (defaults to 1).
-      # * <tt>:separator</tt>  - Sets the separator between the units (defaults to ".").
+      # * <tt>:precision</tt>  - Sets the precision of the number (defaults to 3).
+      # * <tt>:significant</tt>  - If +true+, precision will be the # of significant_digits. If +false+, the # of fractional digits (defaults to +true+)
+      # * <tt>:separator</tt>  - Sets the separator between the fractional and integer digits (defaults to ".").
       # * <tt>:delimiter</tt>  - Sets the thousands delimiter (defaults to "").
-      #
+      # * <tt>:strip_insignificant_zeros</tt>  - If +true+ removes insignificant zeros after the decimal separator (defaults to +true+)
       # ==== Examples
       #  number_to_human_size(123)                                          # => 123 Bytes
-      #  number_to_human_size(1234)                                         # => 1.2 KB
+      #  number_to_human_size(1234)                                         # => 1.21 KB
       #  number_to_human_size(12345)                                        # => 12.1 KB
-      #  number_to_human_size(1234567)                                      # => 1.2 MB
-      #  number_to_human_size(1234567890)                                   # => 1.1 GB
-      #  number_to_human_size(1234567890123)                                # => 1.1 TB
-      #  number_to_human_size(1234567, :precision => 2)                     # => 1.18 MB
-      #  number_to_human_size(483989, :precision => 0)                      # => 473 KB
-      #  number_to_human_size(1234567, :precision => 2, :separator => ',')  # => 1,18 MB
+      #  number_to_human_size(1234567)                                      # => 1.18 MB
+      #  number_to_human_size(1234567890)                                   # => 1.15 GB
+      #  number_to_human_size(1234567890123)                                # => 1.12 TB
+      #  number_to_human_size(1234567, :precision => 2)                     # => 1.2 MB
+      #  number_to_human_size(483989, :precision => 2)                      # => 470 KB
+      #  number_to_human_size(1234567, :precision => 2, :separator => ',')  # => 1,2 MB
       #
-      # Zeros after the decimal point are always stripped out, regardless of the
-      # specified precision:
-      #  helper.number_to_human_size(1234567890123, :precision => 5)        # => "1.12283 TB"
-      #  helper.number_to_human_size(524288000, :precision=>5)              # => "500 MB"
+      # Unsignificant zeros after the fractional separator are stripped out by default (set
+      # <tt>:strip_insignificant_zeros</tt> to +false+ to change that):
+      #  number_to_human_size(1234567890123, :precision => 5)        # => "1.1229 TB"
+      #  number_to_human_size(524288000, :precision=>5)              # => "500 MB"
       #
       # You can still use <tt>number_to_human_size</tt> with the old API that accepts the
       # +precision+ as its optional second parameter:
-      #  number_to_human_size(1234567, 2)    # => 1.18 MB
-      #  number_to_human_size(483989, 0)     # => 473 KB
+      #  number_to_human_size(1234567, 1)    # => 1 MB
+      #  number_to_human_size(483989, 2)     # => 470 KB
       def number_to_human_size(number, *args)
-        return nil if number.nil?
-
         options = args.extract_options!
         options.symbolize_keys!
 
-        defaults = I18n.translate(:'number.format', :locale => options[:locale], :raise => true) rescue {}
-        human    = I18n.translate(:'number.human.format', :locale => options[:locale], :raise => true) rescue {}
+        number = begin
+          Float(number)
+        rescue ArgumentError, TypeError
+          if options[:raise]
+            raise InvalidNumberError, number
+          else
+            return number
+          end
+        end
+
+        defaults = I18n.translate(:'number.format', :locale => options[:locale], :default => {})
+        human    = I18n.translate(:'number.human.format', :locale => options[:locale], :default => {})
         defaults = defaults.merge(human)
 
         unless args.empty?
           ActiveSupport::Deprecation.warn('number_to_human_size takes an option hash ' +
             'instead of a separate precision argument.', caller)
-          precision = args[0] || defaults[:precision]
+          options[:precision] ||= args[0] if args[0]
         end
 
-        precision ||= (options[:precision] || defaults[:precision])
-        separator ||= (options[:separator] || defaults[:separator])
-        delimiter ||= (options[:delimiter] || defaults[:delimiter])
+        options = options.reverse_merge(defaults)
+        #for backwards compatibility with those that didn't add strip_insignificant_zeros to their locale files
+        options[:strip_insignificant_zeros] = true if not options.key?(:strip_insignificant_zeros)
 
         storage_units_format = I18n.translate(:'number.human.storage_units.format', :locale => options[:locale], :raise => true)
 
         if number.to_i < 1024
           unit = I18n.translate(:'number.human.storage_units.units.byte', :locale => options[:locale], :count => number.to_i, :raise => true)
-          storage_units_format.gsub(/%n/, number.to_i.to_s).gsub(/%u/, unit)
+          storage_units_format.gsub(/%n/, number.to_i.to_s).gsub(/%u/, unit).html_safe
         else
           max_exp  = STORAGE_UNITS.size - 1
-          number   = Float(number)
           exponent = (Math.log(number) / Math.log(1024)).to_i # Convert to base 1024
           exponent = max_exp if exponent > max_exp # we need this to avoid overflow for the highest unit
           number  /= 1024 ** exponent
@@ -295,15 +366,138 @@ module ActionView
           unit_key = STORAGE_UNITS[exponent]
           unit = I18n.translate(:"number.human.storage_units.units.#{unit_key}", :locale => options[:locale], :count => number, :raise => true)
 
-          escaped_separator = Regexp.escape(separator)
-          formatted_number = number_with_precision(number,
-            :precision => precision,
-            :separator => separator,
-            :delimiter => delimiter
-          ).sub(/(#{escaped_separator})(\d*[1-9])?0+\z/, '\1\2').sub(/#{escaped_separator}\z/, '')
-          storage_units_format.gsub(/%n/, formatted_number).gsub(/%u/, unit)
+          formatted_number = number_with_precision(number, options)
+          storage_units_format.gsub(/%n/, formatted_number).gsub(/%u/, unit).html_safe
+        end
+      end
+
+      DECIMAL_UNITS = {0 => :unit, 1 => :ten, 2 => :hundred, 3 => :thousand, 6 => :million, 9 => :billion, 12 => :trillion, 15 => :quadrillion,
+        -1 => :deci, -2 => :centi, -3 => :mili, -6 => :micro, -9 => :nano, -12 => :pico, -15 => :femto}.freeze
+
+      # Pretty prints (formats and approximates) a number in a way it is more readable by humans
+      # (eg.: 1200000000 becomes "1.2 Billion"). This is useful for numbers that
+      # can get very large (and too hard to read).
+      #
+      # See <tt>number_to_human_size</tt> if you want to print a file size.
+      #
+      # You can also define you own unit-quantifier names if you want to use other decimal units
+      # (eg.: 1500 becomes "1.5 kilometers", 0.150 becomes "150 mililiters", etc). You may define
+      # a wide range of unit quantifiers, even fractional ones (centi, deci, mili, etc).
+      #
+      # ==== Options
+      # * <tt>:precision</tt>  - Sets the precision of the number (defaults to 3).
+      # * <tt>:significant</tt>  - If +true+, precision will be the # of significant_digits. If +false+, the # of fractional digits (defaults to +true+)
+      # * <tt>:separator</tt>  - Sets the separator between the fractional and integer digits (defaults to ".").
+      # * <tt>:delimiter</tt>  - Sets the thousands delimiter (defaults to "").
+      # * <tt>:strip_insignificant_zeros</tt>  - If +true+ removes insignificant zeros after the decimal separator (defaults to +true+)
+      # * <tt>:units</tt> - A Hash of unit quantifier names. Or a string containing an i18n scope where to find this hash. It might have the following keys:
+      #   * *integers*: <tt>:unit</tt>, <tt>:ten</tt>, <tt>:hundred</tt>, <tt>:thousand</tt>,  <tt>:million</tt>,  <tt>:billion</tt>, <tt>:trillion</tt>, <tt>:quadrillion</tt>
+      #   * *fractionals*: <tt>:deci</tt>, <tt>:centi</tt>, <tt>:mili</tt>, <tt>:micro</tt>, <tt>:nano</tt>, <tt>:pico</tt>, <tt>:femto</tt>
+      # * <tt>:format</tt> - Sets the format of the output string (defaults to "%n %u"). The field types are:
+      #
+      #     %u  The quantifier (ex.: 'thousand')
+      #     %n  The number
+      #
+      # ==== Examples
+      #  number_to_human(123)                                          # => "123"
+      #  number_to_human(1234)                                         # => "1.23 Thousand"
+      #  number_to_human(12345)                                        # => "12.3 Thousand"
+      #  number_to_human(1234567)                                      # => "1.23 Million"
+      #  number_to_human(1234567890)                                   # => "1.23 Billion"
+      #  number_to_human(1234567890123)                                # => "1.23 Trillion"
+      #  number_to_human(1234567890123456)                             # => "1.23 Quadrillion"
+      #  number_to_human(1234567890123456789)                          # => "1230 Quadrillion"
+      #  number_to_human(489939, :precision => 2)                      # => "490 Thousand"
+      #  number_to_human(489939, :precision => 4)                      # => "489.9 Thousand"
+      #  number_to_human(1234567, :precision => 4,
+      #                           :significant => false)               # => "1.2346 Million"
+      #  number_to_human(1234567, :precision => 1,
+      #                           :separator => ',',
+      #                           :significant => false)               # => "1,2 Million"
+      #
+      # Unsignificant zeros after the decimal separator are stripped out by default (set
+      # <tt>:strip_insignificant_zeros</tt> to +false+ to change that):
+      #  number_to_human(12345012345, :significant_digits => 6)       # => "12.345 Billion"
+      #  number_to_human(500000000, :precision=>5)                    # => "500 Million"
+      #
+      # ==== Custom Unit Quantifiers
+      #
+      # You can also use your own custom unit quantifiers:
+      #  number_to_human(500000, :units => {:unit => "ml", :thousand => "lt"})  # => "500 lt"
+      #
+      # If in your I18n locale you have:
+      #   distance:
+      #     centi:
+      #       one: "centimeter"
+      #       other: "centimeters"
+      #     unit:
+      #       one: "meter"
+      #       other: "meters"
+      #     thousand:
+      #       one: "kilometer"
+      #       other: "kilometers"
+      #     billion: "gazilion-distance"
+      #
+      # Then you could do:
+      #
+      #  number_to_human(543934, :units => :distance)                              # => "544 kilometers"
+      #  number_to_human(54393498, :units => :distance)                            # => "54400 kilometers"
+      #  number_to_human(54393498000, :units => :distance)                         # => "54.4 gazilion-distance"
+      #  number_to_human(343, :units => :distance, :precision => 1)                # => "300 meters"
+      #  number_to_human(1, :units => :distance)                                   # => "1 meter"
+      #  number_to_human(0.34, :units => :distance)                                # => "34 centimeters"
+      #
+      def number_to_human(number, options = {})
+        options.symbolize_keys!
+
+        number = begin
+          Float(number)
+        rescue ArgumentError, TypeError
+          if options[:raise]
+            raise InvalidNumberError, number
+          else
+            return number
+          end
         end
+
+        defaults = I18n.translate(:'number.format', :locale => options[:locale], :default => {})
+        human    = I18n.translate(:'number.human.format', :locale => options[:locale], :default => {})
+        defaults = defaults.merge(human)
+
+        options = options.reverse_merge(defaults)
+        #for backwards compatibility with those that didn't add strip_insignificant_zeros to their locale files
+        options[:strip_insignificant_zeros] = true if not options.key?(:strip_insignificant_zeros)
+
+        units = options.delete :units
+        unit_exponents = case units
+        when Hash
+          units
+        when String, Symbol
+          I18n.translate(:"#{units}", :locale => options[:locale], :raise => true)
+        when nil
+          I18n.translate(:"number.human.decimal_units.units", :locale => options[:locale], :raise => true)
+        else
+          raise ArgumentError, ":units must be a Hash or String translation scope."
+        end.keys.map{|e_name| DECIMAL_UNITS.invert[e_name] }.sort_by{|e| -e}
+
+        number_exponent = Math.log10(number).floor
+        display_exponent = unit_exponents.find{|e| number_exponent >= e }
+        number  /= 10 ** display_exponent
+
+        unit = case units
+        when Hash
+          units[DECIMAL_UNITS[display_exponent]]
+        when String, Symbol
+          I18n.translate(:"#{units}.#{DECIMAL_UNITS[display_exponent]}", :locale => options[:locale], :count => number.to_i)
+        else
+          I18n.translate(:"number.human.decimal_units.units.#{DECIMAL_UNITS[display_exponent]}", :locale => options[:locale], :count => number.to_i)
+        end
+
+        decimal_format = options[:format] || I18n.translate(:'number.human.decimal_units.format', :locale => options[:locale], :default => "%n %u")
+        formatted_number = number_with_precision(number, options)
+        decimal_format.gsub(/%n/, formatted_number).gsub(/%u/, unit).strip.html_safe
       end
+
     end
   end
 end
diff --git a/actionpack/lib/action_view/helpers/prototype_helper.rb b/actionpack/lib/action_view/helpers/prototype_helper.rb
index be49b5cc28..ccdc8181db 100644
--- a/actionpack/lib/action_view/helpers/prototype_helper.rb
+++ b/actionpack/lib/action_view/helpers/prototype_helper.rb
@@ -35,7 +35,7 @@ module ActionView
     #
     # ...through a form...
     #
-    #  <% form_remote_tag :url => '/shipping' do -%>
+    #  <%= form_remote_tag :url => '/shipping' do -%>
     #    <div><%= submit_tag 'Recalculate Shipping' %></div>
     #  <% end -%>
     #
@@ -102,39 +102,6 @@ module ActionView
                          :form, :with, :update, :script, :type ]).merge(CALLBACKS)
       end
 
-      # Returns a button with the given +name+ text that'll trigger a JavaScript +function+ using the
-      # onclick handler.
-      #
-      # The first argument +name+ is used as the button's value or display text.
-      #
-      # The next arguments are optional and may include the javascript function definition and a hash of html_options.
-      #
-      # The +function+ argument can be omitted in favor of an +update_page+
-      # block, which evaluates to a string when the template is rendered
-      # (instead of making an Ajax request first).
-      #
-      # The +html_options+ will accept a hash of html attributes for the link tag. Some examples are :class => "nav_button", :id => "articles_nav_button"
-      #
-      # Note: if you choose to specify the javascript function in a block, but would like to pass html_options, set the +function+ parameter to nil
-      #
-      # Examples:
-      #   button_to_function "Greeting", "alert('Hello world!')"
-      #   button_to_function "Delete", "if (confirm('Really?')) do_delete()"
-      #   button_to_function "Details" do |page|
-      #     page[:details].visual_effect :toggle_slide
-      #   end
-      #   button_to_function "Details", :class => "details_button" do |page|
-      #     page[:details].visual_effect :toggle_slide
-      #   end
-      def button_to_function(name, *args, &block)
-        html_options = args.extract_options!.symbolize_keys
-
-        function = block_given? ? update_page(&block) : args[0] || ''
-        onclick = "#{"#{html_options[:onclick]}; " if html_options[:onclick]}#{function};"
-
-        tag(:input, html_options.merge(:type => 'button', :value => name, :onclick => onclick))
-      end
-
       # Returns the JavaScript needed for a remote function.
       # Takes the same arguments as link_to_remote.
       #
@@ -180,13 +147,10 @@ module ActionView
       # #include_helpers_from_context has nothing to overwrite.
       class JavaScriptGenerator #:nodoc:
         def initialize(context, &block) #:nodoc:
-          context._evaluate_assigns_and_ivars
           @context, @lines = context, []
-          @context.update_details(:formats => [:js, :html]) do
-            include_helpers_from_context
-            @context.with_output_buffer(@lines) do
-              @context.instance_exec(self, &block)
-            end
+          include_helpers_from_context
+          @context.with_output_buffer(@lines) do
+            @context.instance_exec(self, &block)
           end
         end
 
@@ -616,7 +580,7 @@ module ActionView
       #     page.hide 'spinner'
       #   end
       def update_page(&block)
-        JavaScriptGenerator.new(@template, &block).to_s.html_safe
+        JavaScriptGenerator.new(view_context, &block).to_s.html_safe
       end
 
       # Works like update_page but wraps the generated JavaScript in a <script>
@@ -690,6 +654,10 @@ module ActionView
         @generator << root if root
       end
 
+      def is_a?(klass)
+        klass == JavaScriptProxy
+      end
+
       private
         def method_missing(method, *arguments, &block)
           if method.to_s =~ /(.*)=$/
@@ -883,5 +851,3 @@ module ActionView
     end
   end
 end
-
-require 'action_view/helpers/javascript_helper'
diff --git a/actionpack/lib/action_view/helpers/record_tag_helper.rb b/actionpack/lib/action_view/helpers/record_tag_helper.rb
index 31411dc08a..a9cf15f418 100644
--- a/actionpack/lib/action_view/helpers/record_tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/record_tag_helper.rb
@@ -4,7 +4,7 @@ module ActionView
       # Produces a wrapper DIV element with id and class parameters that
       # relate to the specified Active Record object. Usage example:
       #
-      #    <% div_for(@person, :class => "foo") do %>
+      #    <%= div_for(@person, :class => "foo") do %>
       #       <%=h @person.name %>
       #    <% end %>
       #
@@ -19,7 +19,7 @@ module ActionView
       # content_tag_for creates an HTML element with id and class parameters
       # that relate to the specified Active Record object. For example:
       #
-      #    <% content_tag_for(:tr, @person) do %>
+      #    <%= content_tag_for(:tr, @person) do %>
       #      <td><%=h @person.first_name %></td>
       #      <td><%=h @person.last_name %></td>
       #    <% end %>
@@ -31,7 +31,7 @@ module ActionView
       #
       # If you require the HTML id attribute to have a prefix, you can specify it:
       #
-      #    <% content_tag_for(:tr, @person, :foo) do %> ...
+      #    <%= content_tag_for(:tr, @person, :foo) do %> ...
       #
       # produces:
       #
@@ -41,7 +41,7 @@ module ActionView
       # additional HTML attributes. If you specify a <tt>:class</tt> value, it will be combined
       # with the default class name for your object. For example:
       #
-      #    <% content_tag_for(:li, @person, :class => "bar") %>...
+      #    <%= content_tag_for(:li, @person, :class => "bar") %>...
       #
       # produces:
       #
diff --git a/actionpack/lib/action_view/helpers/tag_helper.rb b/actionpack/lib/action_view/helpers/tag_helper.rb
index d9d2588a2a..9b4cacd4d7 100644
--- a/actionpack/lib/action_view/helpers/tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/tag_helper.rb
@@ -65,7 +65,7 @@ module ActionView
       #   content_tag("select", options, :multiple => true)
       #    # => <select multiple="multiple">...options...</select>
       #
-      #   <% content_tag :div, :class => "strong" do -%>
+      #   <%= content_tag :div, :class => "strong" do -%>
       #     Hello world!
       #   <% end -%>
       #    # => <div class="strong">Hello world!</div>
@@ -109,7 +109,7 @@ module ActionView
 
         def content_tag_string(name, content, options, escape = true)
           tag_options = tag_options(options, escape) if options
-          ("<#{name}#{tag_options}>".html_safe << content.to_s).safe_concat("</#{name}>")
+          "<#{name}#{tag_options}>#{ERB::Util.h(content)}</#{name}>".html_safe
         end
 
         def tag_options(options, escape = true)
diff --git a/actionpack/lib/action_view/helpers/text_helper.rb b/actionpack/lib/action_view/helpers/text_helper.rb
index b19a9754f4..27be1690dd 100644
--- a/actionpack/lib/action_view/helpers/text_helper.rb
+++ b/actionpack/lib/action_view/helpers/text_helper.rb
@@ -17,7 +17,7 @@ module ActionView
       #       concat "hello"
       #       # is the equivalent of <%= "hello" %>
       #
-      #       if (logged_in == true):
+      #       if logged_in
       #         concat "Logged in!"
       #       else
       #         concat link_to('login', :action => login)
@@ -29,7 +29,7 @@ module ActionView
       end
 
       def safe_concat(string)
-        output_buffer.safe_concat(string)
+        output_buffer.respond_to?(:safe_concat) ? output_buffer.safe_concat(string) : concat(string)
       end
 
       # Truncates a given +text+ after a given <tt>:length</tt> if +text+ is longer than <tt>:length</tt>
@@ -415,7 +415,7 @@ module ActionView
       #                {:first => 'Emily', :middle => 'Shannon', :maiden => 'Pike', :last => 'Hicks'},
       #               {:first => 'June', :middle => 'Dae', :last => 'Jones'}]
       #   <% @items.each do |item| %>
-      #     <tr class="<%= cycle("even", "odd", :name => "row_class") -%>">
+      #     <tr class="<%= cycle("odd", "even", :name => "row_class") -%>">
       #       <td>
       #         <% item.values.each do |value| %>
       #           <%# Create a named cycle "colors" %>
@@ -576,7 +576,7 @@ module ActionView
         # each email is yielded and the result is used as the link text.
         def auto_link_email_addresses(text, html_options = {})
           body = text.dup
-          text.gsub(/([\w\.!#\$%\-+.]+@[A-Za-z0-9\-]+(\.[A-Za-z0-9\-]+)+)/) do
+          text.gsub(/([\w\.!#\$%\-+]+@[A-Za-z0-9\-]+(\.[A-Za-z0-9\-]+)+)/) do
             text = $1
 
             if body.match(/<a\b[^>]*>(.*)(#{Regexp.escape(text)})(.*)<\/a>/)
diff --git a/actionpack/lib/action_view/helpers/translation_helper.rb b/actionpack/lib/action_view/helpers/translation_helper.rb
index 8a89ee58a0..457944dbb6 100644
--- a/actionpack/lib/action_view/helpers/translation_helper.rb
+++ b/actionpack/lib/action_view/helpers/translation_helper.rb
@@ -13,7 +13,7 @@ module ActionView
       def translate(key, options = {})
         options[:raise] = true
         translation = I18n.translate(scope_key_by_partial(key), options)
-        translation.is_a?(Array) ? translation.map { |entry| entry.html_safe } : translation.html_safe
+        (translation.respond_to?(:join) ? translation.join : translation).html_safe
       rescue I18n::MissingTranslationData => e
         keys = I18n.normalize_keys(e.locale, e.key, e.options[:scope])
         content_tag('span', keys.join(', '), :class => 'translation_missing')
@@ -29,9 +29,10 @@ module ActionView
       private
 
         def scope_key_by_partial(key)
-          if (key.respond_to?(:join) ? key.join : key.to_s).first == "."
+          strkey = key.respond_to?(:join) ? key.join : key.to_s
+          if strkey.first == "."
             if @_virtual_path
-              @_virtual_path.gsub(%r{/_?}, ".") + key.to_s
+              @_virtual_path.gsub(%r{/_?}, ".") + strkey
             else
               raise "Cannot use t(#{key.inspect}) shortcut because path is not available"
             end
diff --git a/actionpack/lib/action_view/helpers/url_helper.rb b/actionpack/lib/action_view/helpers/url_helper.rb
index 148f2868e9..b23d5fcb68 100644
--- a/actionpack/lib/action_view/helpers/url_helper.rb
+++ b/actionpack/lib/action_view/helpers/url_helper.rb
@@ -1,6 +1,7 @@
 require 'action_view/helpers/javascript_helper'
 require 'active_support/core_ext/array/access'
 require 'active_support/core_ext/hash/keys'
+require 'action_dispatch'
 
 module ActionView
   module Helpers #:nodoc:
@@ -9,6 +10,9 @@ module ActionView
     # This allows you to use the same format for links in views
     # and controllers.
     module UrlHelper
+      extend ActiveSupport::Concern
+
+      include ActionDispatch::Routing::UrlFor
       include JavaScriptHelper
 
       # Need to map default url options to controller one.
@@ -16,6 +20,10 @@ module ActionView
         controller.send(:default_url_options, *args)
       end
 
+      def url_options
+        controller.url_options
+      end
+
       # Returns the URL for the set of +options+ provided. This takes the
       # same options as +url_for+ in Action Controller (see the
       # documentation for <tt>ActionController::Base#url_for</tt>). Note that by default
@@ -162,7 +170,7 @@ module ActionView
       #
       # 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 %>
+      #   <%= link_to(@profile) do %>
       #     <strong><%= @profile.name %></strong> -- <span>Check it out!</span>
       #   <% end %>
       #   # => <a href="/profiles/1">
@@ -206,7 +214,7 @@ module ActionView
         if block_given?
           options      = args.first || {}
           html_options = args.second
-          safe_concat(link_to(capture(&block), options, html_options))
+          link_to(capture(&block), options, html_options)
         else
           name         = args[0]
           options      = args[1] || {}
@@ -224,7 +232,7 @@ module ActionView
           end
 
           href_attr = "href=\"#{url}\"" unless href
-          ("<a #{href_attr}#{tag_options}>".html_safe << (name || url)).safe_concat("</a>")
+          "<a #{href_attr}#{tag_options}>#{ERB::Util.h(name || url)}</a>".html_safe
         end
       end
 
@@ -578,8 +586,6 @@ module ActionView
           add_confirm_to_attributes!(html_options, confirm) if confirm
           add_method_to_attributes!(html_options, method)   if method
 
-          html_options["data-url"] = options[:url] if options.is_a?(Hash) && options[:url]
-
           html_options
         end
 
diff --git a/actionpack/lib/action_view/locale/en.yml b/actionpack/lib/action_view/locale/en.yml
index a3548051c1..a3e2230f6f 100644
--- a/actionpack/lib/action_view/locale/en.yml
+++ b/actionpack/lib/action_view/locale/en.yml
@@ -9,6 +9,11 @@
       delimiter: ","
       # Number of decimals, behind the separator (the number 1 with a precision of 2 gives: 1.00)
       precision: 3
+      # If set to true, precision will mean the number of significant digits instead
+      # of the number of decimal digits (1234 with precision 2 becomes 1200, 1.23543 becomes 1.2)
+      significant: false
+      # If set, the zeros after the decimal separator will always be stripped (eg.: 1.200 will be 1.2)
+      strip_insignificant_zeros: false
 
     # Used in number_to_currency()
     currency:
@@ -16,34 +21,43 @@
         # Where is the currency sign? %u is the currency unit, %n the number (default: $5.00)
         format: "%u%n"
         unit: "$"
-        # These three are to override number.format and are optional
+        # These five are to override number.format and are optional
         separator: "."
         delimiter: ","
         precision: 2
+        significant: false
+        strip_insignificant_zeros: false
 
     # Used in number_to_percentage()
     percentage:
       format:
-        # These three are to override number.format and are optional
+        # These five are to override number.format and are optional
         # separator:
         delimiter: ""
         # precision:
+        # significant: false
+        # strip_insignificant_zeros: false
 
     # Used in number_to_precision()
     precision:
       format:
-        # These three are to override number.format and are optional
+        # These five are to override number.format and are optional
         # separator:
         delimiter: ""
         # precision:
+        # significant: false
+        # strip_insignificant_zeros: false
 
-    # Used in number_to_human_size()
+    # Used in number_to_human_size() and number_to_human()
     human:
       format:
-        # These three are to override number.format and are optional
+        # These five are to override number.format and are optional
         # separator:
         delimiter: ""
-        precision: 1
+        precision: 3
+        significant: true
+        strip_insignificant_zeros: true
+      # Used in number_to_human_size()
       storage_units:
         # Storage units output formatting.
         # %u is the storage unit, %n is the number (default: 2 MB)
@@ -56,6 +70,31 @@
           mb: "MB"
           gb: "GB"
           tb: "TB"
+      # Used in number_to_human()
+      decimal_units:
+        format: "%n %u"
+        # Decimal units output formatting
+        # By default we will only quantify some of the exponents
+        # but the commented ones might be defined or overridden
+        # by the user.
+        units:
+          # femto: Quadrillionth
+          # pico: Trillionth
+          # nano: Billionth
+          # micro: Millionth
+          # mili: Thousandth
+          # centi: Hundredth
+          # deci: Tenth
+          unit: ""
+          # ten:
+          #   one: Ten
+          #   other: Tens
+          # hundred: Hundred
+          thousand: Thousand
+          million: Million
+          billion: Billion
+          trillion: Trillion
+          quadrillion: Quadrillion
 
   # Used in distance_of_time_in_words(), distance_of_time_in_words_to_now(), time_ago_in_words()
   datetime:
diff --git a/actionpack/lib/action_view/lookup_context.rb b/actionpack/lib/action_view/lookup_context.rb
index 91885c7370..9b59aac0eb 100644
--- a/actionpack/lib/action_view/lookup_context.rb
+++ b/actionpack/lib/action_view/lookup_context.rb
@@ -1,4 +1,4 @@
-require 'active_support/core_ext/object/try'
+require 'active_support/core_ext/array/wrap'
 require 'active_support/core_ext/object/blank'
 
 module ActionView
@@ -11,38 +11,56 @@ module ActionView
     @@fallbacks = [FileSystemResolver.new(""), FileSystemResolver.new("/")]
 
     mattr_accessor :registered_details
-    self.registered_details = {}
+    self.registered_details = []
+
+    def self.register_detail(name, options = {}, &block)
+      self.registered_details << name
+      Accessors.send :define_method, :"_#{name}_defaults", &block
+      Accessors.module_eval <<-METHOD, __FILE__, __LINE__ + 1
+        def #{name}
+          @details[:#{name}]
+        end
 
-    def self.register_detail(name, options = {})
-      registered_details[name] = lambda do |value|
-        value = Array(value.presence || yield)
-        value |= [nil] unless options[:allow_nil] == false
-        value
-      end
+        def #{name}=(value)
+          value = Array.wrap(value.presence || _#{name}_defaults)
+
+          if value != @details[:#{name}]
+            @details_key = nil
+            @details = @details.dup if @details.frozen?
+            @details[:#{name}] = value.freeze
+          end
+        end
+      METHOD
+    end
+
+    # Holds accessors for the registered details.
+    module Accessors #:nodoc:
     end
 
     register_detail(:formats) { Mime::SET.symbols }
     register_detail(:locale)  { [I18n.locale] }
 
     class DetailsKey #:nodoc:
-      attr_reader :details
       alias :eql? :equal?
+      alias :object_hash :hash
 
+      attr_reader :hash
       @details_keys = Hash.new
 
       def self.get(details)
-        @details_keys[details] ||= new(details)
+        @details_keys[details.freeze] ||= new
       end
 
-      def initialize(details)
-        @details, @hash = details, details.hash
+      def initialize
+        @hash = object_hash
       end
     end
 
     def initialize(view_paths, details = {})
-      @details_key = nil
+      @details, @details_key = { :handlers => default_handlers }, nil
+      @frozen_formats = false
       self.view_paths = view_paths
-      self.details = details
+      self.update_details(details, true)
     end
 
     module ViewPaths
@@ -55,18 +73,20 @@ module ActionView
       end
 
       def find(name, prefix = nil, partial = false)
-        @view_paths.find(name, prefix, partial || false, details, details_key)
+        @view_paths.find(*args_for_lookup(name, prefix, partial))
       end
+      alias :find_template :find
 
       def find_all(name, prefix = nil, partial = false)
-        @view_paths.find_all(name, prefix, partial || false, details, details_key)
+        @view_paths.find_all(*args_for_lookup(name, prefix, partial))
       end
 
       def exists?(name, prefix = nil, partial = false)
-        @view_paths.exists?(name, prefix, partial || false, details, details_key)
+        @view_paths.exists?(*args_for_lookup(name, prefix, partial))
       end
+      alias :template_exists? :exists?
 
-      # Add fallbacks to the view paths. Useful in cases you are rendering a file.
+      # Add fallbacks to the view paths. Useful in cases you are rendering a :file.
       def with_fallbacks
         added_resolvers = 0
         self.class.fallbacks.each do |resolver|
@@ -78,73 +98,92 @@ module ActionView
       ensure
         added_resolvers.times { view_paths.pop }
       end
-    end
 
-    module Details
-      attr_reader :details
+    protected
+
+      def args_for_lookup(name, prefix, partial) #:nodoc:
+        name, prefix = normalize_name(name, prefix)
+        [name, prefix, partial || false, @details, details_key]
+      end
+
+      # Support legacy foo.erb names even though we now ignore .erb
+      # as well as incorrectly putting part of the path in the template
+      # name instead of the prefix.
+      def normalize_name(name, prefix) #:nodoc:
+        name  = name.to_s.gsub(handlers_regexp, '')
+        parts = name.split('/')
+        return parts.pop, [prefix, *parts].compact.join("/")
+      end
+
+      def default_handlers #:nodoc:
+        @default_handlers ||= Template::Handlers.extensions
+      end
 
-      def details=(details)
-        @details = normalize_details(details)
-        @details_key = nil if @details_key && @details_key.details != @details
+      def handlers_regexp #:nodoc:
+        @handlers_regexp ||= /\.(?:#{default_handlers.join('|')})$/
       end
+    end
 
-      def details_key
+    module Details
+      # Calculate the details key. Remove the handlers from calculation to improve performance
+      # since the user cannot modify it explicitly.
+      def details_key #:nodoc:
         @details_key ||= DetailsKey.get(@details)
       end
 
-      # Shortcut to read formats from details.
-      def formats
-        @details[:formats].compact
+      # Freeze the current formats in the lookup context. By freezing them, you are guaranteeing
+      # that next template lookups are not going to modify the formats. The controller can also
+      # use this, to ensure that formats won't be further modified (as it does in respond_to blocks).
+      def freeze_formats(formats, unless_frozen=false) #:nodoc:
+        return if unless_frozen && @frozen_formats
+        self.formats = formats
+        @frozen_formats = true
       end
 
-      # Shortcut to set formats in details.
+      # Overload formats= to reject [:"*/*"] values.
       def formats=(value)
-        self.details = @details.merge(:formats => value)
+        value = nil    if value == [:"*/*"]
+        value << :html if value == [:js]
+        super(value)
       end
 
-      # Shortcut to read locale.
+      # Overload locale to return a symbol instead of array
       def locale
-        I18n.locale
+        @details[:locale].first
       end
 
-      # Shortcut to set locale in details and I18n.
+      # Overload locale= to also set the I18n.locale. If the current I18n.config object responds
+      # to i18n_config, it means that it's has a copy of the original I18n configuration and it's
+      # acting as proxy, which we need to skip.
       def locale=(value)
-        I18n.locale = value
-
-        unless I18n.config.respond_to?(:lookup_context)
-          self.details = @details.merge(:locale => value)
+        if value
+          config = I18n.config.respond_to?(:i18n_config) ? I18n.config.i18n_config : I18n.config
+          config.locale = value
         end
+        super(I18n.locale)
       end
 
       # Update the details keys by merging the given hash into the current
       # details hash. If a block is given, the details are modified just during
       # the execution of the block and reverted to the previous value after.
-      def update_details(new_details)
-        old_details  = @details
-        self.details = old_details.merge(new_details)
+      def update_details(new_details, force=false)
+        old_details = @details.dup
+
+        registered_details.each do |key|
+          send(:"#{key}=", new_details[key]) if force || new_details.key?(key)
+        end
 
         if block_given?
           begin
             yield
           ensure
-            self.details = old_details
+            @details = old_details
           end
         end
       end
-
-    protected
-
-      def normalize_details(details)
-        details = details.dup
-        # TODO: Refactor this concern out of the resolver
-        details.delete(:formats) if details[:formats] == [:"*/*"]
-        self.class.registered_details.each do |k, v|
-          details[k] = v.call(details[k])
-        end
-        details.freeze
-      end
     end
 
+    include Accessors
     include Details
     include ViewPaths
   end
diff --git a/actionpack/lib/action_view/railtie.rb b/actionpack/lib/action_view/railtie.rb
index 2e5d115630..9cf007cd2b 100644
--- a/actionpack/lib/action_view/railtie.rb
+++ b/actionpack/lib/action_view/railtie.rb
@@ -3,10 +3,10 @@ require "rails"
 
 module ActionView
   class Railtie < Rails::Railtie
-    railtie_name :action_view
+    config.action_view = ActiveSupport::OrderedOptions.new
 
     require "action_view/railties/log_subscriber"
-    log_subscriber ActionView::Railties::LogSubscriber.new
+    log_subscriber :action_view, ActionView::Railties::LogSubscriber.new
 
     initializer "action_view.cache_asset_timestamps" do |app|
       unless app.config.cache_classes
@@ -15,5 +15,13 @@ module ActionView
         end
       end
     end
+
+    initializer "action_view.set_configs" do |app|
+      ActionView.base_hook do
+        app.config.action_view.each do |k,v|
+          send "#{k}=", v
+        end
+      end
+    end
   end
 end
\ No newline at end of file
diff --git a/actionpack/lib/action_view/render/layouts.rb b/actionpack/lib/action_view/render/layouts.rb
index 8688de3d18..578f39d817 100644
--- a/actionpack/lib/action_view/render/layouts.rb
+++ b/actionpack/lib/action_view/render/layouts.rb
@@ -1,8 +1,5 @@
-require 'active_support/core_ext/object/try'
-
 module ActionView
   module Layouts
-
     # You can think of a layout as a method that is called with a block. _layout_for
     # returns the contents that are yielded to the layout. If the user calls yield
     # :some_name, the block, by default, returns content_for(:some_name). If the user
@@ -13,7 +10,7 @@ module ActionView
     # ==== Example
     #
     #   # The template
-    #   <% render :layout => "my_layout" do %>Content<% end %>
+    #   <%= render :layout => "my_layout" do %>Content<% end %>
     #
     #   # The layout
     #   <html><% yield %></html>
@@ -27,7 +24,7 @@ module ActionView
     # ==== Example
     #
     #   # The template
-    #   <% render :layout => "my_layout" do |customer| %>Hello <%= customer.name %><% end %>
+    #   <%= render :layout => "my_layout" do |customer| %>Hello <%= customer.name %><% end %>
     #
     #   # The layout
     #   <html><% yield Struct.new(:name).new("David") %></html>
@@ -46,17 +43,28 @@ module ActionView
     # This is the method which actually finds the layout using details in the lookup
     # context object. If no layout is found, it checkes if at least a layout with
     # the given name exists across all details before raising the error.
-    def _find_layout(layout) #:nodoc:
+    #
+    # If self.formats contains several formats, just the first one is considered in
+    # the layout lookup.
+    def find_layout(layout)
       begin
-        layout =~ /^\// ?
-          with_fallbacks { find(layout) } : find(layout)
+        if formats.size == 1
+          _find_layout(layout)
+        else
+          update_details(:formats => self.formats.first){ _find_layout(layout) }
+        end
       rescue ActionView::MissingTemplate => e
         update_details(:formats => nil) do
-          raise unless exists?(layout)
+          raise unless template_exists?(layout)
         end
       end
     end
 
+    def _find_layout(layout) #:nodoc:
+      layout =~ /^\// ?
+        with_fallbacks { find_template(layout) } : find_template(layout)
+    end
+
     # Contains the logic that actually renders the layout.
     def _render_layout(layout, locals, &block) #:nodoc:
       layout.render(self, locals){ |*name| _layout_for(*name, &block) }
diff --git a/actionpack/lib/action_view/render/partials.rb b/actionpack/lib/action_view/render/partials.rb
index 950c9d2cd8..17d16556b9 100644
--- a/actionpack/lib/action_view/render/partials.rb
+++ b/actionpack/lib/action_view/render/partials.rb
@@ -123,7 +123,7 @@ module ActionView
   # You can also apply a layout to a block within any template:
   #
   #   <%# app/views/users/_chief.html.erb &>
-  #   <% render(:layout => "administrator", :locals => { :user => chief }) do %>
+  #   <%= render(:layout => "administrator", :locals => { :user => chief }) do %>
   #     Title: <%= chief.title %>
   #   <% end %>
   #
@@ -146,7 +146,7 @@ module ActionView
   #   </div>
   #
   #   <%# app/views/users/index.html.erb &>
-  #   <% render :layout => @users do |user| %>
+  #   <%= render :layout => @users do |user| %>
   #     Title: <%= user.title %>
   #   <% end %>
   #
@@ -162,7 +162,7 @@ module ActionView
   #   </div>
   #
   #   <%# app/views/users/index.html.erb &>
-  #   <% render :layout => @users do |user, section| %>
+  #   <%= render :layout => @users do |user, section| %>
   #     <%- case section when :header -%>
   #       Title: <%= user.title %>
   #     <%- when :footer -%>
@@ -294,7 +294,7 @@ module ActionView
       def find_template(path=@path)
         return path unless path.is_a?(String)
         prefix = @view.controller_path unless path.include?(?/)
-        @view.find(path, prefix, true)
+        @view.find_template(path, prefix, true)
       end
 
       def partial_path(object = @object)
diff --git a/actionpack/lib/action_view/render/rendering.rb b/actionpack/lib/action_view/render/rendering.rb
index 47ea70f5ad..492326964a 100644
--- a/actionpack/lib/action_view/render/rendering.rb
+++ b/actionpack/lib/action_view/render/rendering.rb
@@ -12,14 +12,17 @@ module ActionView
     #
     # If no options hash is passed or :update specified, the default is to render a partial and use the second parameter
     # as the locals hash.
-    def render(options = {}, locals = {}, &block) #:nodoc:
+    def render(options = {}, locals = {}, &block)
       case options
       when Hash
         if block_given?
-          content = _render_partial(options.merge(:partial => options[:layout]), &block)
-          safe_concat(content)
+          _render_partial(options.merge(:partial => options[:layout]), &block)
+        elsif options.key?(:partial)
+          _render_partial(options)
         else
-          _render(options)
+          template = _determine_template(options)
+          lookup_context.freeze_formats(template.formats, true)
+          _render_template(template, options[:layout], options)
         end
       when :update
         update_page(&block)
@@ -28,44 +31,18 @@ module ActionView
       end
     end
 
-    # This is the API to render a ViewContext's template from a controller.
-    def render_template(options, &block)
-      _evaluate_assigns_and_ivars
-
-      # TODO Layout for partials should be handled here, because inside the
-      # partial renderer it looks for the layout as a partial.
-      if options.key?(:partial) && options[:layout]
-        options[:layout] = _find_layout(options[:layout])
-      end
-
-      _render(options, &block)
-    end
-
-    # This method holds the common render logic for both controllers and
-    # views rendering stacks.
-    def _render(options) #:nodoc:
-      if options.key?(:partial)
-        _render_partial(options)
-      else
-        template = _determine_template(options)
-        yield template if block_given?
-        _render_template(template, options[:layout], options)
-      end
-    end
-
     # Determine the template to be rendered using the given options.
     def _determine_template(options) #:nodoc:
       if options.key?(:inline)
         handler = Template.handler_class_for_extension(options[:type] || "erb")
         Template.new(options[:inline], "inline template", handler, {})
       elsif options.key?(:text)
-        Template::Text.new(options[:text], self.formats.try(:first))
-      elsif options.key?(:_template)
-        options[:_template]
+        Template::Text.new(options[:text], formats.try(:first))
       elsif options.key?(:file)
-        with_fallbacks { find(options[:file], options[:prefix]) }
+        with_fallbacks { find_template(options[:file], options[:prefix]) }
       elsif options.key?(:template)
-        find(options[:template], options[:prefix])
+        options[:template].respond_to?(:render) ?
+          options[:template] : find_template(options[:template], options[:prefix])
       end
     end
 
@@ -73,22 +50,17 @@ module ActionView
     # supplied as well.
     def _render_template(template, layout = nil, options = {}) #:nodoc:
       locals = options[:locals] || {}
-      layout = _find_layout(layout) if layout
+      layout = find_layout(layout) if layout
 
       ActiveSupport::Notifications.instrument("action_view.render_template",
-        :identifier => template.identifier, :layout => layout.try(:identifier)) do
+        :identifier => template.identifier, :layout => layout.try(:virtual_path)) do
 
         content = template.render(self, locals) { |*name| _layout_for(*name) }
         @_content_for[:layout] = content
 
-        if layout
-          @_layout = layout.identifier
-          content  = _render_layout(layout, locals)
-        end
-
+        content = _render_layout(layout, locals) if layout
         content
       end
     end
-
   end
 end
diff --git a/actionpack/lib/action_view/template.rb b/actionpack/lib/action_view/template.rb
index b4fdb49d3b..8abc1633ff 100644
--- a/actionpack/lib/action_view/template.rb
+++ b/actionpack/lib/action_view/template.rb
@@ -1,8 +1,7 @@
 # encoding: utf-8
 # This is so that templates compiled in this file are UTF-8
-
-require 'set'
-require "action_view/template/resolver"
+require 'active_support/core_ext/array/wrap'
+require 'active_support/core_ext/object/blank'
 
 module ActionView
   class Template
@@ -24,19 +23,20 @@ module ActionView
       @identifier = identifier
       @handler    = handler
 
-      @partial      = details[:partial]
       @virtual_path = details[:virtual_path]
       @method_names = {}
 
-      format    = details[:format]
-      format  ||= handler.default_format.to_sym if handler.respond_to?(:default_format)
-      format  ||= :html
-      @formats  = [format.to_sym]
+      format   = details[:format] || :html
+      @formats = Array.wrap(format).map(&:to_sym)
     end
 
     def render(view, locals, &block)
-      method_name = compile(locals, view)
-      view.send(method_name, locals, &block)
+      # Notice that we use a bang in this instrumentation because you don't want to
+      # consume this in production. This is only slow if it's being listened to.
+      ActiveSupport::Notifications.instrument("action_view.render_template!", :virtual_path => @virtual_path) do
+        method_name = compile(locals, view)
+        view.send(method_name, locals, &block)
+      end
     rescue Exception => e
       if e.is_a?(Template::Error)
         e.sub_template_of(self)
@@ -58,10 +58,6 @@ module ActionView
       @counter_name ||= "#{variable_name}_counter".to_sym
     end
 
-    def partial?
-      @partial
-    end
-
     def inspect
       if defined?(Rails.root)
         identifier.sub("#{Rails.root}/", '')
diff --git a/actionpack/lib/action_view/template/error.rb b/actionpack/lib/action_view/template/error.rb
index 648f708d3d..5222ffa89c 100644
--- a/actionpack/lib/action_view/template/error.rb
+++ b/actionpack/lib/action_view/template/error.rb
@@ -1,6 +1,26 @@
 require "active_support/core_ext/enumerable"
 
 module ActionView
+  class ActionViewError < StandardError #:nodoc:
+  end
+
+  class MissingTemplate < ActionViewError #:nodoc:
+    attr_reader :path
+
+    def initialize(paths, path, details, partial)
+      @path = path
+      display_paths = paths.compact.map{ |p| p.to_s.inspect }.join(", ")
+      template_type = if partial
+        "partial"
+      elsif path =~ /layouts/i
+        'layout'
+      else
+        'template'
+      end
+
+      super("Missing #{template_type} #{path} with #{details.inspect} in view paths #{display_paths}")
+    end
+  end
   class Template
     # The Template::Error exception is raised when the compilation of the template fails. This exception then gathers a
     # bunch of intimate details and uses it to report a very precise exception message.
@@ -73,11 +93,11 @@ module ActionView
       end
 
       def to_s
-        "\n#{self.class} (#{message}) #{source_location}:\n" + 
+        "\n#{self.class} (#{message}) #{source_location}:\n" +
         "#{source_extract}\n    #{clean_backtrace.join("\n    ")}\n\n"
       end
 
-      # don't do anything nontrivial here. Any raised exception from here becomes fatal 
+      # don't do anything nontrivial here. Any raised exception from here becomes fatal
       # (and can't be rescued).
       def backtrace
         @backtrace
diff --git a/actionpack/lib/action_view/template/handlers/erb.rb b/actionpack/lib/action_view/template/handlers/erb.rb
index 937694ce8e..705c2bf82e 100644
--- a/actionpack/lib/action_view/template/handlers/erb.rb
+++ b/actionpack/lib/action_view/template/handlers/erb.rb
@@ -3,46 +3,16 @@ require 'active_support/core_ext/string/output_safety'
 require 'erubis'
 
 module ActionView
-  class OutputBuffer
-    def initialize
-      @buffer = ActiveSupport::SafeBuffer.new
-    end
-
-    def safe_concat(value)
-      @buffer.safe_concat(value)
-    end
-
+  class OutputBuffer < ActiveSupport::SafeBuffer
     def <<(value)
-      @buffer << value.to_s
-    end
-
-    def length
-      @buffer.length
+      super(value.to_s)
     end
+    alias :append= :<<
 
-    def [](*args)
-      @buffer[*args]
-    end
-
-    def to_s
-      @buffer.to_s
-    end
-
-    def to_str
-      @buffer.to_str
-    end
-
-    def empty?
-      @buffer.empty?
-    end
-
-    def html_safe?
-      @buffer.html_safe?
-    end
-
-    if "".respond_to?(:force_encoding)
-      def force_encoding(encoding)
-        @buffer.force_encoding(encoding)
+    def append_if_string=(value)
+      if value.is_a?(String) && !value.is_a?(NonConcattingString)
+        ActiveSupport::Deprecation.warn("<% %> style block helpers are deprecated. Please use <%= %>", caller)
+        self << value
       end
     end
   end
@@ -58,16 +28,26 @@ module ActionView
         src << "@output_buffer.safe_concat('" << escape_text(text) << "');"
       end
 
+      BLOCK_EXPR = /(do|\{)(\s*\|[^|]*\|)?\s*\Z/
+
       def add_expr_literal(src, code)
-        if code =~ /(do|\{)(\s*\|[^|]*\|)?\s*\Z/
-          src << '@output_buffer << ' << code
+        if code =~ BLOCK_EXPR
+          src << '@output_buffer.append= ' << code
+        else
+          src << '@output_buffer.append= (' << code << ');'
+        end
+      end
+
+      def add_stmt(src, code)
+        if code =~ BLOCK_EXPR
+          src << '@output_buffer.append_if_string= ' << code
         else
-          src << '@output_buffer << (' << code << ');'
+          super
         end
       end
 
       def add_expr_escaped(src, code)
-        src << '@output_buffer << ' << escaped_expr(code) << ';'
+        src << '@output_buffer.append= ' << escaped_expr(code) << ';'
       end
 
       def add_postamble(src)
diff --git a/actionpack/lib/action_view/template/handlers/rjs.rb b/actionpack/lib/action_view/template/handlers/rjs.rb
index 63e7dc0902..128be5077c 100644
--- a/actionpack/lib/action_view/template/handlers/rjs.rb
+++ b/actionpack/lib/action_view/template/handlers/rjs.rb
@@ -6,8 +6,7 @@ module ActionView
       self.default_format = Mime::JS
 
       def compile(template)
-        "controller.response.content_type ||= Mime::JS;" +
-          "update_page do |page|;#{template.source}\nend"
+        "update_page do |page|;#{template.source}\nend"
       end
 
       def default_format
diff --git a/actionpack/lib/action_view/template/resolver.rb b/actionpack/lib/action_view/template/resolver.rb
index a43597e728..8e8afaa43f 100644
--- a/actionpack/lib/action_view/template/resolver.rb
+++ b/actionpack/lib/action_view/template/resolver.rb
@@ -1,6 +1,5 @@
 require "pathname"
 require "active_support/core_ext/class"
-require "active_support/core_ext/array/wrap"
 require "action_view/template"
 
 module ActionView
@@ -14,15 +13,8 @@ module ActionView
       @cached.clear
     end
 
-    def find(*args)
-      find_all(*args).first
-    end
-
     # Normalizes the arguments and passes it on to find_template.
     def find_all(name, prefix=nil, partial=false, details={}, key=nil)
-      name, prefix = normalize_name(name, prefix)
-      details = details.merge(:handlers => default_handlers)
-
       cached(key, prefix, name, partial) do
         find_templates(name, prefix, partial, details)
       end
@@ -34,10 +26,6 @@ module ActionView
       @caching ||= !defined?(Rails.application) || Rails.application.config.cache_classes
     end
 
-    def default_handlers
-      Template::Handlers.extensions + [nil]
-    end
-
     # This is what child classes implement. No defaults are needed
     # because Resolver guarantees that the arguments are present and
     # normalized.
@@ -45,17 +33,6 @@ module ActionView
       raise NotImplementedError
     end
 
-    # Support legacy foo.erb names even though we now ignore .erb
-    # as well as incorrectly putting part of the path in the template
-    # name instead of the prefix.
-    def normalize_name(name, prefix)
-      handlers = Template::Handlers.extensions.join('|')
-      name = name.to_s.gsub(/\.(?:#{handlers})$/, '')
-
-      parts = name.split('/')
-      return parts.pop, [prefix, *parts].compact.join("/")
-    end
-
     def cached(key, prefix, name, partial)
       return yield unless key && caching?
       scope = @cached[key][prefix][name]
@@ -79,7 +56,7 @@ module ActionView
 
     def find_templates(name, prefix, partial, details)
       path = build_path(name, prefix, partial, details)
-      query(partial, path, EXTENSION_ORDER.map { |ext| details[ext] })
+      query(path, EXTENSION_ORDER.map { |ext| details[ext] }, details[:formats])
     end
 
     def build_path(name, prefix, partial, details)
@@ -89,26 +66,32 @@ module ActionView
       path
     end
 
-    def query(partial, path, exts)
+    def query(path, exts, formats)
       query = File.join(@path, path)
 
       exts.each do |ext|
-        query << '{' << ext.map {|e| e && ".#{e}" }.join(',') << '}'
+        query << '{' << ext.map {|e| e && ".#{e}" }.join(',') << ',}'
       end
 
       Dir[query].reject { |p| File.directory?(p) }.map do |p|
-        handler, format = extract_handler_and_format(p)
+        handler, format = extract_handler_and_format(p, formats)
         Template.new(File.read(p), File.expand_path(p), handler,
-          :partial => partial, :virtual_path => path, :format => format)
+          :virtual_path => path, :format => format)
       end
     end
 
-    def extract_handler_and_format(path)
+    # Extract handler and formats from path. If a format cannot be a found neither
+    # from the path, or the handler, we should return the array of formats given
+    # to the resolver.
+    def extract_handler_and_format(path, default_formats)
       pieces = File.basename(path).split(".")
       pieces.shift
 
-      handler = Template.handler_class_for_extension(pieces.pop)
-      format  = pieces.last && Mime[pieces.last] && pieces.pop.to_sym
+      handler  = Template.handler_class_for_extension(pieces.pop)
+      format   = pieces.last && Mime[pieces.last] && pieces.pop.to_sym
+      format ||= handler.default_format if handler.respond_to?(:default_format)
+      format ||= default_formats
+
       [handler, format]
     end
   end
diff --git a/actionpack/lib/action_view/template/text.rb b/actionpack/lib/action_view/template/text.rb
index df394b0fb0..269340514c 100644
--- a/actionpack/lib/action_view/template/text.rb
+++ b/actionpack/lib/action_view/template/text.rb
@@ -1,10 +1,12 @@
 module ActionView #:nodoc:
   class Template
     class Text < String #:nodoc:
-      def initialize(string, content_type = nil)
+      attr_accessor :mime_type
+
+      def initialize(string, mime_type = nil)
         super(string.to_s)
-        @content_type   = Mime[content_type] || content_type if content_type
-        @content_type ||= Mime::TEXT
+        @mime_type   = Mime[mime_type] || mime_type if mime_type
+        @mime_type ||= Mime::TEXT
       end
 
       def identifier
@@ -19,12 +21,8 @@ module ActionView #:nodoc:
         to_s
       end
 
-      def mime_type
-        @content_type
-      end
-
       def formats
-        [@content_type.to_sym]
+        [@mime_type.to_sym]
       end
 
       def partial?
diff --git a/actionpack/lib/action_view/test_case.rb b/actionpack/lib/action_view/test_case.rb
index 1578ac9479..b0ababe344 100644
--- a/actionpack/lib/action_view/test_case.rb
+++ b/actionpack/lib/action_view/test_case.rb
@@ -2,29 +2,10 @@ require 'action_controller/test_case'
 require 'action_view'
 
 module ActionView
-  class Base
-    alias_method :initialize_without_template_tracking, :initialize
-    def initialize(*args)
-      @_rendered = { :template => nil, :partials => Hash.new(0) }
-      initialize_without_template_tracking(*args)
-    end
-
-    attr_internal :rendered
-  end
-
-  class Template
-    alias_method :render_without_tracking, :render
-    def render(view, locals, &blk)
-      rendered = view.rendered
-      rendered[:partials][self] += 1 if partial?
-      rendered[:template] ||= []
-      rendered[:template] << self
-      render_without_tracking(view, locals, &blk)
-    end
-  end
-
   class TestCase < ActiveSupport::TestCase
     class TestController < ActionController::Base
+      include ActionDispatch::TestProcess
+
       attr_accessor :request, :response, :params
 
       def self.controller_path
@@ -42,6 +23,7 @@ module ActionView
     end
 
     include ActionDispatch::Assertions, ActionDispatch::TestProcess
+    include ActionController::TemplateAssertions
     include ActionView::Context
 
     include ActionController::PolymorphicRoutes
@@ -64,7 +46,7 @@ module ActionView
     end
 
     def config
-      @controller.config
+      @controller.config if @controller.respond_to?(:config)
     end
 
     def render(options = {}, local_assigns = {}, &block)
@@ -124,7 +106,8 @@ module ActionView
 
       def _view
         view = ActionView::Base.new(ActionController::Base.view_paths, _assigns, @controller)
-        view.class.send :include, _helpers
+        view.singleton_class.send :include, _helpers
+        view.singleton_class.send :include, @controller._router.url_helpers
         view.output_buffer = self.output_buffer
         view
       end