1 files changed, 42 insertions, 0 deletions
diff --git a/actioncable/lib/action_cable/helpers/action_cable_helper.rb b/actioncable/lib/action_cable/helpers/action_cable_helper.rb
new file mode 100644
index 0000000000..df16c02e83
--- /dev/null
+++ b/actioncable/lib/action_cable/helpers/action_cable_helper.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+module ActionCable
+  module Helpers
+    module ActionCableHelper
+      # Returns an "action-cable-url" meta tag with the value of the URL specified in your
+      # configuration. Ensure this is above your JavaScript tag:
+      #
+      #   <head>
+      #     <%= action_cable_meta_tag %>
+      #     <%= javascript_include_tag 'application', 'data-turbolinks-track' => 'reload' %>
+      #   </head>
+      #
+      # This is then used by Action Cable to determine the URL of your WebSocket server.
+      # Your CoffeeScript can then connect to the server without needing to specify the
+      # URL directly:
+      #
+      #   #= require cable
+      #   @App = {}
+      #   App.cable = Cable.createConsumer()
+      #
+      # Make sure to specify the correct server location in each of your environment
+      # config files:
+      #
+      #   config.action_cable.mount_path = "/cable123"
+      #   <%= action_cable_meta_tag %> would render:
+      #   => <meta name="action-cable-url" content="/cable123" />
+      #
+      #   config.action_cable.url = "ws://actioncable.com"
+      #   <%= action_cable_meta_tag %> would render:
+      #   => <meta name="action-cable-url" content="ws://actioncable.com" />
+      #
+      def action_cable_meta_tag
+        tag "meta", name: "action-cable-url", content: (
+          ActionCable.server.config.url ||
+          ActionCable.server.config.mount_path ||
+          raise("No Action Cable URL configured -- please configure this at config.action_cable.url")
+        )
+      end
+    end
+  end
+end