wrap translate defaults to use translate helper features

actionpack/lib/action_view/helpers/translation_helper.rb

@@ -45,6 +45,7 @@ module TranslationHelper
       # you know what kind of output to expect when you call translate in a template.
       def translate(key, options = {})
         options.merge!(:rescue_format => :html) unless options.key?(:rescue_format)
+        options[:default] = wrap_translate_defaults(options[:default]) if options[:default]
         if html_safe_translation_key?(key)
           html_safe_options = options.dup
           options.except(*I18n::RESERVED_KEYS).each do |name, value|
@@ -83,6 +84,21 @@ def scope_key_by_partial(key)
         def html_safe_translation_key?(key)
           key.to_s =~ /(\b|_|\.)html$/
         end
+
+        def wrap_translate_defaults(defaults)
+          new_defaults = []
+          defaults     = Array(defaults)
+          while key = defaults.shift
+            if key.is_a?(Symbol)
+              new_defaults << lambda { |_, options| translate key, options.merge(:default => defaults) }
+              break
+            else
+              new_defautls << key
+            end
+          end
+
+          new_defaults
+        end
     end
   end
 end

actionpack/test/fixtures/translations/templates/default.erb

@@ -0,0 +1 @@
+<%= t('.missing', :default => :'.foo') %>

actionpack/test/template/translation_helper_test.rb

@@ -11,7 +11,8 @@ def setup
       :translations => {
         :templates => {
           :found => { :foo => 'Foo' },
-          :array => { :foo => { :bar => 'Foo Bar' } }
+          :array => { :foo => { :bar => 'Foo Bar' } },
+          :default => { :foo => 'Foo' }
         },
         :foo => 'Foo',
         :hello => '<a>Hello World</a>',
@@ -71,6 +72,10 @@ def test_finds_array_of_translations_scoped_by_partial
     assert_equal 'Foo Bar', @view.render(:file => 'translations/templates/array').strip
   end
 
+  def test_default_lookup_scoped_by_partial
+    assert_equal 'Foo', view.render(:file => 'translations/templates/default').strip
+  end
+
   def test_missing_translation_scoped_by_partial
     expected = '<span class="translation_missing" title="translation missing: en.translations.templates.missing.missing">Missing</span>'
     assert_equal expected, view.render(:file => 'translations/templates/missing').strip
@@ -102,4 +107,22 @@ def test_translate_with_html_count
   def test_translation_returning_an_array_ignores_html_suffix
     assert_equal ["foo", "bar"], translate(:'translations.array_html')
   end
+
+  def test_translate_with_default_named_html
+    translation = translate(:'translations.missing', :default => :'translations.hello_html')
+    assert_equal '<a>Hello World</a>', translation
+    assert translation.html_safe?
+  end
+
+  def test_translate_with_two_defaults_named_html
+    translation = translate(:'translations.missing', :default => [:'translations.missing_html', :'translations.hello_html'])
+    assert_equal '<a>Hello World</a>', translation
+    assert translation.html_safe?
+  end
+
+  def test_translate_with_last_default_named_html
+    translation = translate(:'translations.missing', :default => [:'translations.missing', :'translations.hello_html'])
+    assert_equal '<a>Hello World</a>', translation
+    assert translation.html_safe?
+  end
 end