Merge pull request #15021 from hubertlepicki/allow_custom_host_in_asset_url

Allow custom asset host to be passed in asset_url

3 files changed, 30 insertions, 3 deletions

diff --git a/actionview/CHANGELOG.md b/actionview/CHANGELOG.md
index e5740e30c6..147e5b47db 100644
--- a/actionview/CHANGELOG.md
+++ b/actionview/CHANGELOG.md
@@ -1,3 +1,8 @@
+*   Allow custom `:host` option to be passed to `asset_url` helper that
+    overwrites `config.action_controller.asset_host` for particular asset.
+
+    *Hubert Łępicki*
+
 *   Deprecate `AbstractController::Base.parent_prefixes`.
     Override `AbstractController::Base.local_prefixes` when you want to change
     where to find views.
@@ -95,5 +100,4 @@
 
     *Piotr Chmolowski, Łukasz Strzałkowski*
 
-
 Please check [4-1-stable](https://github.com/rails/rails/blob/4-1-stable/actionview/CHANGELOG.md) for previous changes.
diff --git a/actionview/lib/action_view/helpers/asset_url_helper.rb b/actionview/lib/action_view/helpers/asset_url_helper.rb
index 41997a85b3..ae684af87b 100644
--- a/actionview/lib/action_view/helpers/asset_url_helper.rb
+++ b/actionview/lib/action_view/helpers/asset_url_helper.rb
@@ -147,7 +147,14 @@ module ActionView
 
       # Computes the full URL to an asset in the public directory. This
       # will use +asset_path+ internally, so most of their behaviors
-      # will be the same.
+      # will be the same. If :host options is set, it overwrites global
+      # +config.action_controller.asset_host+ setting.
+      #
+      # All other options provided are forwarded to +asset_path+ call.
+      #
+      #   asset_url "application.js"                                 # => http://example.com/application.js
+      #   asset_url "application.js", host: "http://cdn.example.com" # => http://cdn.example.com/javascripts/application.js
+      #
       def asset_url(source, options = {})
         path_to_asset(source, options.merge(:protocol => :request))
       end
@@ -191,7 +198,8 @@ module ActionView
       # (proc or otherwise).
       def compute_asset_host(source = "", options = {})
         request = self.request if respond_to?(:request)
-        host = config.asset_host if defined? config.asset_host
+        host = options[:host]
+        host ||= config.asset_host if defined? config.asset_host
         host ||= request.base_url if request && options[:protocol] == :request
 
         if host.respond_to?(:call)
diff --git a/actionview/test/template/asset_tag_helper_test.rb b/actionview/test/template/asset_tag_helper_test.rb
index 18e4277d7a..343681b5a9 100644
--- a/actionview/test/template/asset_tag_helper_test.rb
+++ b/actionview/test/template/asset_tag_helper_test.rb
@@ -596,6 +596,10 @@ class AssetTagHelperNonVhostTest < ActionView::TestCase
     assert_equal "gopher://www.example.com", compute_asset_host("foo", :protocol => :request)
   end
 
+  def test_should_return_custom_host_if_passed_in_options
+    assert_equal "http://custom.example.com", compute_asset_host("foo", :host => "http://custom.example.com")
+  end
+
   def test_should_ignore_relative_root_path_on_complete_url
     assert_dom_equal(%(http://www.example.com/images/xml.png), image_path("http://www.example.com/images/xml.png"))
   end
@@ -759,4 +763,15 @@ class AssetUrlHelperEmptyModuleTest < ActionView::TestCase
     assert @module.config.asset_host
     assert_equal "http://www.example.com/foo", @module.asset_url("foo")
   end
+
+  def test_asset_url_with_custom_asset_host
+    @module.instance_eval do
+      def config
+        Struct.new(:asset_host).new("http://www.example.com")
+      end
+    end
+
+    assert @module.config.asset_host
+    assert_equal "http://custom.example.com/foo", @module.asset_url("foo", :host => "http://custom.example.com")
+  end
 end