[Haml] Don't clobber dynamic_form in Rails 3 beta.

This is actually covering up a bug in dynamic_form,
which should hopefully get fixed soon.

Closes gh-134

doc-src/HAML_CHANGELOG.md

@@ -3,13 +3,14 @@
 * Table of contents
 {:toc}
 
-## 2.2.24
+## 2.2.24 (Unreleased)
 
-[Tagged on GitHub](http://github.com/nex3/haml/commit/2.2.24).
+* Don't prevent ActiveModel form elements from having error formatting applied.
 
 * Make sure `form_for` blocks are properly indented under Rails 3.0.0.beta.3.
 
-* Don't prevent ActiveModel form elements from having error formatting applied.
+* Don't activate a bug in the `dynamic_form` plugin under Rails 3.0.0.beta.3
+  that would cause its methods not to be loaded.
 
 ## 2.2.23
 

lib/haml/helpers.rb

@@ -1,8 +1,3 @@
-if defined?(ActionView)
-  require 'haml/helpers/action_view_mods'
-  require 'haml/helpers/action_view_extensions'
-end
-
 module Haml
   # This module contains various helpful methods to make it easier to do various tasks.
   # {Haml::Helpers} is automatically included in the context
@@ -52,8 +47,7 @@ MESSAGE
 
     self.extend self
 
-    @@action_view_defined = defined?(ActionView)
-    @@force_no_action_view = false
+    @@action_view_defined = false
 
     # @return [Boolean] Whether or not ActionView is loaded
     def self.action_view?
@@ -572,8 +566,6 @@ END
       _erbout = _hamlout.buffer
       proc { |*args| proc.call(*args) }
     end
-
-    include ActionViewExtensions if self.const_defined? "ActionViewExtensions"
   end
 end
 

lib/haml/helpers/action_view_extensions.rb

@@ -1,7 +1,7 @@
-require 'haml/helpers/action_view_mods'
-
 module Haml
   module Helpers
+    @@action_view_defined = true
+
     # This module contains various useful helper methods
     # that either tie into ActionView or the rest of the ActionPack stack,
     # or are only useful in that context.
@@ -51,5 +51,7 @@ module Haml
         @_haml_concat_raw = old
       end
     end
+
+    include ActionViewExtensions
   end
 end

lib/haml/railtie.rb

@@ -3,10 +3,14 @@
 # Yehuda promises there will be soon,
 # and once there is we should switch to that.
 
-if defined?(Rails::Railtie)
+if defined?(ActiveSupport) && Haml::Util.has?(:public_method, ActiveSupport, :on_load)
+  # Rails 3.0.0.beta.2+
+  ActiveSupport.on_load(:action_view) {Haml.init_rails(binding)}
+elsif defined?(Rails::Railtie)
+  # Rails 3.0.0.beta1
   module Haml
     class Railtie < Rails::Railtie
-      initializer :haml do
+      ActiveSupport.on_load(:action_view) do
         Haml.init_rails(binding)
       end
     end

lib/haml/template.rb

@@ -1,4 +1,6 @@
 require 'haml/engine'
+require 'haml/helpers/action_view_mods'
+require 'haml/helpers/action_view_extensions'
 
 module Haml
   # The class that keeps track of the global options for Haml within Rails.