Allow customisation of asset path generation using a proc.

Set config.action_controller.asset_path_template to a proc that takes one
argument - the direct, unchanged asset path - and returns a path to that asset
using the scheme that your assets require.

This is useful if you have a setup which scales by introducing new application
servers where the mtime of the asset files may not be the same as those of the
asset files on your previous servers, but it does require your web servers to
have knowledge of the asset template paths that you rewrite to so it's not
suitable for out-of-the-box use. An example of configuring asset path
generation and rewriting these paths using Apache is included in
actionpack/lib/action_view/helpers/asset_tag_helper.rb.

Signed-off-by: wycats <wycats@gmail.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/actionpack/test/template/asset_tag_helper_test.rb b/actionpack/test/template/asset_tag_helper_test.rb
index c471df861d..43d11df8fe 100644
--- a/actionpack/test/template/asset_tag_helper_test.rb
+++ b/actionpack/test/template/asset_tag_helper_test.rb
@@ -373,6 +373,15 @@ class AssetTagHelperTest < ActionView::TestCase
     assert_equal %(<img alt="Rails" src="/images/rails.png?#{expected_time}" />), image_tag("rails.png")
   end
 
+  def test_proc_asset_id
+    @controller.config.asset_path_template = Proc.new do |asset_path|
+      "/assets.v12345#{asset_path}"
+    end
+
+    expected_path = "/assets.v12345/images/rails.png"
+    assert_equal %(<img alt="Rails" src="#{expected_path}" />), image_tag("rails.png")
+  end
+
   def test_timebased_asset_id_with_relative_url_root
     @controller.config.relative_url_root = "/collaboration/hieraki"
     expected_time = File.stat(File.expand_path(File.dirname(__FILE__) + "/../fixtures/public/images/rails.png")).mtime.to_i.to_s