support rails 2 and 3, also fail or autoload classes we depend on to …

…prevent silent failures

lib/http_accept_language.rb

@@ -54,12 +54,13 @@ def compatible_language_from(available_languages)
       end
     end.compact.first
   end
-
 end
-if defined?(ActionDispatch::Request)
-  ActionDispatch::Request.send :include, HttpAcceptLanguage
-elsif defined?(ActionDispatch::AbstractRequest)
-  ActionDispatch::AbstractRequest.send :include, HttpAcceptLanguage
-elsif defined?(ActionDispatch::CgiRequest)
-  ActionDispatch::CgiRequest.send :include, HttpAcceptLanguage
+
+if defined?(ActionPack)
+  classes = if ActionPack::VERSION::MAJOR == 2
+    [ActionController::Request, ActionController::CgiRequest]
+  else
+    [ActionDispatch::Request]
+  end
+  classes.each{|c| c.send :include, HttpAcceptLanguage }
 end

test/http_accept_language_test.rb

@@ -2,6 +2,24 @@
 require 'http_accept_language'
 require 'test/unit'
 
+module ActionPack
+  module VERSION
+    MAJOR = 3
+  end
+end
+
+module ActionDispatch
+  class Request
+  end
+end
+
+module ActionController
+  class CgiRequest
+  end
+  class Request
+  end
+end
+
 class MockedCgiRequest
   include HttpAcceptLanguage
   def env
@@ -37,13 +55,39 @@ def test_should_find_first_compatible_from_user_preferred
     request.env['HTTP_ACCEPT_LANGUAGE'] = 'en-us,de-de'
     assert_equal 'en', request.compatible_language_from(%w{de en})
   end
-  
+
   def test_should_accept_symbols_as_available_languages
     request.env['HTTP_ACCEPT_LANGUAGE'] = 'en-us'
     assert_equal :"en-HK", request.compatible_language_from([:"en-HK"])
   end
 
+  def test_should_be_included_into_actionpack_v2
+    silence_warnings do
+      ActionPack::VERSION.const_set(:MAJOR, 2)
+    end
+    load "http_accept_language.rb"
+
+    assert_include ActionController::Request.ancestors, HttpAcceptLanguage
+    assert_include ActionController::CgiRequest.ancestors, HttpAcceptLanguage
+  end
+
+  def test_should_be_included_into_actionpack_v3
+    silence_warnings do
+      ActionPack::VERSION.const_set(:MAJOR, 3)
+    end
+    load "http_accept_language.rb"
+    assert_include ActionDispatch::Request.ancestors, HttpAcceptLanguage
+  end
+
   private
+
+  def silence_warnings
+    old_verbose, $VERBOSE = $VERBOSE, nil
+    yield
+  ensure
+    $VERBOSE = old_verbose
+  end
+
   def request
     @request ||= MockedCgiRequest.new
   end