feat(js): Dynamic ActionCable URL (#35579)

* Failing test case

* feat: Dynamic Url Generation

Change createWebSocketURL to be a closure that allows url to be evaluated at the time the webSocket is established

* refactor: createWebSocketURL to Consumer, remove need for closure

Move initial call to createWebSocketURL in createConsumer

* docs: Add documentation for dynamic url and string args to createConsumer

Co-Authored-By: rmacklin <rmacklin@users.noreply.github.com>

[Ryan Castner, rmacklin]

1 files changed, 17 insertions, 0 deletions

diff --git a/guides/source/action_cable_overview.md b/guides/source/action_cable_overview.md
index c531b6eee2..7bf6a73797 100644
--- a/guides/source/action_cable_overview.md
+++ b/guides/source/action_cable_overview.md
@@ -190,6 +190,23 @@ This will ready a consumer that'll connect against `/cable` on your server by de
 The connection won't be established until you've also specified at least one subscription
 you're interested in having.
 
+The consumer can optionally take an argument that specifies the url to connect to. This
+can be a string, or a function that returns a string that will be called when the
+WebSocket is opened.
+
+```js
+// Specify a different url to connect to
+createConsumer('https://ws.example.com/cable')
+
+// Use a function to dynamically generate the url
+createConsumer(getWebSocketURL)
+
+function getWebSocketURL {
+  const token = localStorage.get('auth-token')
+  return `https://ws.example.com/cable?token=${token}`
+}
+```
+
 #### Subscriber
 
 A consumer becomes a subscriber by creating a subscription to a given channel: