2 files changed, 31 insertions, 1 deletions
diff --git a/actionview/lib/action_view/helpers/date_helper.rb b/actionview/lib/action_view/helpers/date_helper.rb
index 43de922f74..a98620833e 100644
--- a/actionview/lib/action_view/helpers/date_helper.rb
+++ b/actionview/lib/action_view/helpers/date_helper.rb
@@ -1009,7 +1009,7 @@ module ActionView
         # Builds the css class value for the select element
         #  css_class_attribute(:year, 'date optional', with_css_classes: { year: 'my-year' })
         #  => "date optional my-year"
-        def css_class_attribute(type, html_options_class, options)
+        def css_class_attribute(type, html_options_class, options) # :nodoc:
           css_class = case options
             when Hash
               options[type.to_sym]
diff --git a/actionview/lib/action_view/helpers/output_safety_helper.rb b/actionview/lib/action_view/helpers/output_safety_helper.rb
index c0fc3b820f..d4b55423a8 100644
--- a/actionview/lib/action_view/helpers/output_safety_helper.rb
+++ b/actionview/lib/action_view/helpers/output_safety_helper.rb
@@ -33,6 +33,36 @@ module ActionView #:nodoc:
 
         array.flatten.map! { |i| ERB::Util.unwrapped_html_escape(i) }.join(sep).html_safe
       end
+
+      # Converts the array to a comma-separated sentence where the last element is
+      # joined by the connector word. This is the html_safe-aware version of
+      # ActiveSupport's {Array#to_sentence}[http://api.rubyonrails.org/classes/Array.html#method-i-to_sentence].
+      #
+      def to_sentence(array, options = {})
+        options.assert_valid_keys(:words_connector, :two_words_connector, :last_word_connector, :locale)
+
+        default_connectors = {
+          :words_connector     => ', ',
+          :two_words_connector => ' and ',
+          :last_word_connector => ', and '
+        }
+        if defined?(I18n)
+          i18n_connectors = I18n.translate(:'support.array', locale: options[:locale], default: {})
+          default_connectors.merge!(i18n_connectors)
+        end
+        options = default_connectors.merge!(options)
+
+        case array.length
+        when 0
+          ''.html_safe
+        when 1
+          ERB::Util.html_escape(array[0])
+        when 2
+          safe_join([array[0], array[1]], options[:two_words_connector])
+        else
+          safe_join([safe_join(array[0...-1], options[:words_connector]), options[:last_word_connector], array[-1]])
+        end
+      end
     end
   end
 end