Add *_url helpers to get the full assets URL

Adds `image_url`, `javascript_url`, `stylesheet_url`, `audio_url`,
`video_url`, and `font_url` to assets tag helper. These URL helpers will
return the full path to your assets. This is useful when you are going
to reference this asset from external host.

3 files changed, 46 insertions, 0 deletions

diff --git a/actionpack/lib/action_view/helpers/asset_tag_helper.rb b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
index 40a950c644..7029ca8a8d 100644
--- a/actionpack/lib/action_view/helpers/asset_tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
@@ -278,6 +278,13 @@ module ActionView
       end
       alias_method :path_to_image, :image_path # aliased to avoid conflicts with an image_path named route
 
+      # Computes the full URL to an image asset in the public images directory.
+      # This will use +image_path+ internally, so most of their behaviors will be the same.
+      def image_url(source)
+        URI.join(current_host, path_to_image(source)).to_s
+      end
+      alias_method :url_to_image, :image_url # aliased to avoid conflicts with an image_url named route
+
       # Computes the path to a video asset in the public videos directory.
       # Full paths from the document root will be passed through.
       # Used internally by +video_tag+ to build the video path.
@@ -293,6 +300,13 @@ module ActionView
       end
       alias_method :path_to_video, :video_path # aliased to avoid conflicts with a video_path named route
 
+      # Computes the full URL to a video asset in the public videos directory.
+      # This will use +video_path+ internally, so most of their behaviors will be the same.
+      def video_url(source)
+        URI.join(current_host, path_to_video(source)).to_s
+      end
+      alias_method :url_to_video, :video_url # aliased to avoid conflicts with an video_url named route
+
       # Computes the path to an audio asset in the public audios directory.
       # Full paths from the document root will be passed through.
       # Used internally by +audio_tag+ to build the audio path.
@@ -308,6 +322,13 @@ module ActionView
       end
       alias_method :path_to_audio, :audio_path # aliased to avoid conflicts with an audio_path named route
 
+      # Computes the full URL to a audio asset in the public audios directory.
+      # This will use +audio_path+ internally, so most of their behaviors will be the same.
+      def audio_url(source)
+        URI.join(current_host, path_to_audio(source)).to_s
+      end
+      alias_method :url_to_audio, :audio_url # aliased to avoid conflicts with an audio_url named route
+
       # Computes the path to a font asset in the public fonts directory.
       # Full paths from the document root will be passed through.
       #
@@ -322,6 +343,13 @@ module ActionView
       end
       alias_method :path_to_font, :font_path # aliased to avoid conflicts with an font_path named route
 
+      # Computes the full URL to a font asset in the public fonts directory.
+      # This will use +font_path+ internally, so most of their behaviors will be the same.
+      def font_url(source)
+        URI.join(current_host, path_to_font(source)).to_s
+      end
+      alias_method :url_to_font, :font_url # aliased to avoid conflicts with an font_url named route
+
       # Returns an html image tag for the +source+. The +source+ can be a full
       # path or a file that exists in your public images directory.
       #
@@ -463,6 +491,10 @@ module ActionView
             tag(type, options)
           end
         end
+
+        def current_host
+          url_for(:only_path => false)
+        end
     end
   end
 end
diff --git a/actionpack/lib/action_view/helpers/asset_tag_helpers/javascript_tag_helpers.rb b/actionpack/lib/action_view/helpers/asset_tag_helpers/javascript_tag_helpers.rb
index d9f1f88ade..c67f81dcf4 100644
--- a/actionpack/lib/action_view/helpers/asset_tag_helpers/javascript_tag_helpers.rb
+++ b/actionpack/lib/action_view/helpers/asset_tag_helpers/javascript_tag_helpers.rb
@@ -87,6 +87,13 @@ module ActionView
         end
         alias_method :path_to_javascript, :javascript_path # aliased to avoid conflicts with a javascript_path named route
 
+        # Computes the full URL to a javascript asset in the public javascripts directory.
+        # This will use +javascript_path+ internally, so most of their behaviors will be the same.
+        def javascript_url(source)
+          URI.join(current_host, path_to_javascript(source)).to_s
+        end
+        alias_method :url_to_javascript, :javascript_url # aliased to avoid conflicts with a javascript_url named route
+
         # Returns an HTML script tag for each of the +sources+ provided.
         #
         # Sources may be paths to JavaScript files. Relative paths are assumed to be relative
diff --git a/actionpack/lib/action_view/helpers/asset_tag_helpers/stylesheet_tag_helpers.rb b/actionpack/lib/action_view/helpers/asset_tag_helpers/stylesheet_tag_helpers.rb
index 41958c6559..2584b67548 100644
--- a/actionpack/lib/action_view/helpers/asset_tag_helpers/stylesheet_tag_helpers.rb
+++ b/actionpack/lib/action_view/helpers/asset_tag_helpers/stylesheet_tag_helpers.rb
@@ -65,6 +65,13 @@ module ActionView
         end
         alias_method :path_to_stylesheet, :stylesheet_path # aliased to avoid conflicts with a stylesheet_path named route
 
+        # Computes the full URL to a stylesheet asset in the public stylesheets directory.
+        # This will use +stylesheet_path+ internally, so most of their behaviors will be the same.
+        def stylesheet_url(source)
+          URI.join(current_host, path_to_stylesheet(source)).to_s
+        end
+        alias_method :url_to_stylesheet, :stylesheet_url # aliased to avoid conflicts with a stylesheet_url named route
+
         # Returns a stylesheet link tag for the sources specified as arguments. If
         # you don't specify an extension, <tt>.css</tt> will be appended automatically.
         # You can modify the link attributes by passing a hash as the last argument.