add a generic tranlate view helper

actionpack/lib/action_view/helpers/i18n_helper.rb

@@ -0,0 +1,19 @@
+module ActionView
+  module Helpers 
+    module I18nHelper
+      def translate(*args)
+        # inserts the locale or current request locale to the argument list if no locale 
+        # has been passed or the locale has been passed as part of the options hash
+        options = args.extract_options!
+        if args.size != 2
+          locale = options.delete :locale
+          locale ||= request.locale if respond_to? :request
+          args << locale if locale
+        end
+        args << options unless options.empty?
+        I18n.translate *args
+      end
+      alias :t :translate
+    end
+  end
+end

actionpack/test/template/i18n_helper_test.rb

@@ -0,0 +1,33 @@
+require 'abstract_unit'
+require 'action_view/helpers/i18n_helper'
+
+class I18nHelperTests < Test::Unit::TestCase
+  include ActionView::Helpers::I18nHelper
+
+  attr_reader :request
+  def setup
+    @request = stub :locale => 'en-US'
+    I18n.stubs(:translate).with(:'foo.bar', 'en-US').returns 'Foo Bar'
+  end
+
+  def test_translate_given_a_locale_argument_it_does_not_check_request_for_locale
+    request.expects(:locale).never
+    assert_equal 'Foo Bar', translate(:'foo.bar', :locale => 'en-US')
+  end
+
+  def test_translate_given_a_locale_option_it_does_not_check_request_for_locale
+    request.expects(:locale).never
+    I18n.expects(:translate).with(:'foo.bar', 'en-US').returns 'Foo Bar'
+    assert_equal 'Foo Bar', translate(:'foo.bar', :locale => 'en-US')
+  end
+
+  def test_translate_given_no_locale_it_checks_request_for_locale
+    request.expects(:locale).returns 'en-US'
+    assert_equal 'Foo Bar', translate(:'foo.bar')
+  end
+
+  def test_translate_delegates_to_i18n_translate
+    I18n.expects(:translate).with(:'foo.bar', 'en-US').returns 'Foo Bar'
+    assert_equal 'Foo Bar', translate(:'foo.bar')
+  end
+end