new helpers #favicon_link_tag and #apple_touch_icon_link_tag

actionpack/lib/action_view/helpers/asset_tag_helper.rb

@@ -501,6 +501,44 @@ def stylesheet_link_tag(*sources)
         end
       end
 
+      # Returns a link tag for a favicon.
+      #
+      #   <%= favicon_link_tag %>
+      #
+      # generates
+      #
+      #   <link href="/favicon.ico?4649789979" rel="shortcut icon" type="image/vnd.microsoft.icon" />
+      #
+      # You can specify a different icon file in the first argument:
+      #
+      #   <%= favicon_link_tag 'favicon.ico' %>
+      #
+      # That's passed to +image_path+ as is, so the example above would render
+      #
+      #   <link href="/images/favicon.ico?4649789979" rel="shortcut icon" type="image/vnd.microsoft.icon" />
+      #
+      # The helper accepts an additional options hash where you can override "rel" and "type".
+      def favicon_link_tag(source=nil, options={})
+        tag('link', {
+          :rel  => 'shortcut icon',
+          :type => 'image/vnd.microsoft.icon',
+          :href => image_path(source || '/favicon.ico')
+        }.merge(options.symbolize_keys))
+      end
+
+      # Returns a link tag for an icon targetted at iPod Touch, iPhone, and iPad.
+      #
+      #   <%= apple_touch_icon_link_tag 'my_site.png' %>
+      #
+      # generates
+      #
+      #   <link href="/images/my_site.png?4233872383" rel="apple-touch-icon" />
+      #
+      # The source argument is passed to +image_path+ as is.
+      def apple_touch_icon_link_tag(source)
+        tag('link', :rel => 'apple-touch-icon', :href => image_path(source))
+      end
+
       # Computes the path to an image asset in the public images directory.
       # Full paths from the document root will be passed through.
       # Used internally by +image_tag+ to build the image path.

actionpack/test/template/asset_tag_helper_test.rb

@@ -157,6 +157,17 @@ def teardown
     %(image_tag("mouse.png", :mouseover => image_path("mouse_over.png"))) => %(<img alt="Mouse" onmouseover="this.src='/images/mouse_over.png'" onmouseout="this.src='/images/mouse.png'" src="/images/mouse.png" />)
   }
 
+  FaviconLinkToTag = {
+    %(favicon_link_tag) => %(<link href="/favicon.ico" rel="shortcut icon" type="image/vnd.microsoft.icon" />),
+    %(favicon_link_tag 'favicon.ico') => %(<link href="/images/favicon.ico" rel="shortcut icon" type="image/vnd.microsoft.icon" />),
+    %(favicon_link_tag 'favicon.ico', :rel => 'foo') => %(<link href="/images/favicon.ico" rel="foo" type="image/vnd.microsoft.icon" />),
+    %(favicon_link_tag 'favicon.ico', :rel => 'foo', :type => 'bar') => %(<link href="/images/favicon.ico" rel="foo" type="bar" />)
+  }
+
+  AppleTouchIconLinkToTag = {
+    %(apple_touch_icon_link_tag 'my_site.png') => %(<link href="/images/my_site.png" rel="apple-touch-icon" />)
+  }
+
   VideoPathToTag = {
     %(video_path("xml"))          => %(/videos/xml),
     %(video_path("xml.ogg"))      => %(/videos/xml.ogg),
@@ -331,6 +342,14 @@ def test_image_tag
     ImageLinkToTag.each { |method, tag| assert_dom_equal(tag, eval(method)) }
   end
 
+  def test_favicon_link_tag
+    FaviconLinkToTag.each { |method, tag| assert_dom_equal(tag, eval(method)) }
+  end
+
+  def test_apple_touch_link_tag
+    AppleTouchIconLinkToTag.each { |method, tag| assert_dom_equal(tag, eval(method)) }
+  end
+
   def test_image_tag_windows_behaviour
     old_asset_id, ENV["RAILS_ASSET_ID"] = ENV["RAILS_ASSET_ID"], "1"
     # This simulates the behaviour of File#exist? on windows when testing a file ending in "."