[Haml] Abstract out references to ActionView::Template*.

Closes gh-67

doc-src/HAML_CHANGELOG.md

@@ -3,6 +3,13 @@
 * Table of contents
 {:toc}
 
+## 2.2.16 (Unreleased)
+
+* Abstract out references to `ActionView::TemplateError`,
+  `ActionView::TemplateHandler`, etc.
+  These have all been renamed to `ActionView::Template::*`
+  in Rails 3.0.
+
 ## [2.2.15](http://github.com/nex3/haml/commit/2.2.15)
 
 * Allow `if` statements with no content followed by `else` clauses.

lib/haml/template.rb

@@ -46,7 +46,7 @@ end
 # Decide how we want to load Haml into Rails.
 # Patching was necessary for versions <= 2.0.1,
 # but we can make it a normal handler for higher versions.
-if defined?(ActionView::TemplateHandler)
+if defined?(ActionView::TemplateHandler) || defined?(ActionView::Template::Handler)
   require 'haml/template/plugin'
 else
   require 'haml/template/patch'

lib/haml/template/plugin.rb

@@ -2,8 +2,11 @@
 # using the > 2.0.1 template handler API.
 
 module Haml
-  class Plugin < ActionView::TemplateHandler
-    include ActionView::TemplateHandlers::Compilable if defined?(ActionView::TemplateHandlers::Compilable)
+  class Plugin < Haml::Util.av_template_class(:Handler)
+    if defined?(ActionView::TemplateHandlers::Compilable) ||
+        defined?(ActionView::Template::Handlers::Compilable)
+      include Haml::Util.av_template_class(:Handlers)::Compilable
+    end
 
     def compile(template)
       options = Haml::Template.options.dup
@@ -38,7 +41,8 @@ end.register_template_handler(:haml, Haml::Plugin)
 # In Rails 2.0.2, ActionView::TemplateError took arguments
 # that we can't fill in from the Haml::Plugin context.
 # Thus, we've got to monkeypatch ActionView::Base to catch the error.
-if ActionView::TemplateError.instance_method(:initialize).arity == 5
+if defined?(ActionView::TemplateError) &&
+    ActionView::TemplateError.instance_method(:initialize).arity == 5
   class ActionView::Base
     def compile_template(handler, template, file_name, local_assigns)
       render_symbol = assign_method_name(handler, template, file_name)

lib/haml/util.rb

@@ -146,6 +146,19 @@ module Haml
       return nil
     end
 
+    # Returns an ActionView::Template* class.
+    # In pre-3.0 versions of Rails, most of these classes
+    # were of the form `ActionView::TemplateFoo`,
+    # while afterwards they were of the form `ActionView;:Template::Foo`.
+    #
+    # @param name [#to_s] The name of the class to get.
+    #   For example, `:Error` will return `ActionView::TemplateError`
+    #   or `ActionView::Template::Error`.
+    def av_template_class(name)
+      return ActionView.const_get("Template#{name}") if ActionView.const_defined?("Template#{name}")
+      return ActionView::Template.const_get(name.to_s)
+    end
+
     ## Rails XSS Safety
 
     # Whether or not ActionView's XSS protection is available and enabled,

test/haml/helper_test.rb

@@ -73,7 +73,7 @@ class HelperTest < Test::Unit::TestCase
 
     begin
       ActionView::Base.new.render(:inline => "<%= flatten('Foo\\nBar') %>")
-    rescue NoMethodError, ActionView::TemplateError
+    rescue NoMethodError, Haml::Util.av_template_class(:Error)
       proper_behavior = true
     end
     assert(proper_behavior)

test/haml/template_test.rb

@@ -109,7 +109,7 @@ class TemplateTest < Test::Unit::TestCase
       message = "template: #{name}\nline:     #{line}"
       assert_equal(pair.first, pair.last, message)
     end
-  rescue ActionView::TemplateError => e
+  rescue Haml::Util.av_template_class(:Error) => e
     if e.message =~ /Can't run [\w:]+ filter; required (one of|file) ((?:'\w+'(?: or )?)+)(, but none were found| not found)/
       puts "\nCouldn't require #{$2}; skipping a test."
     else