ActionCable: FE Disconnection Reason

[DosCervezas]

Sorry for breaking your issue pattern but I thought it would be a bit of overkill for my simple issue.

Expected behavior

I would like to specify a specific disconnect reasons, that the FE could catch and react on it.
Therefore I defined Standard error handled it in the handle_open method

class Connection < ActionCable::Connection::Base
...
def handle_open
  super
rescue MultiConnectionError => exception
  close(reason: exception.message, reconnect: false) if websocket.alive?
end
...
end

It works like a charm, the message is broadcasted to the FE

But I cannot catch the reason.. after debugging I found the culprit

The reason is not passed to the close of the websocket

Actual behavior

I would like to catch the reason, why the connection is disconnected. Of course I could do it on the serverside but the reason seems to me a valid other approach.

System configuration

Rails version:
Rails 7.0.4
"@rails/actioncable": "^7.0.4"

Ruby version:
ruby 3.1.2p20

[hahmed]

Hey @DosCervezas, could you upload a repo to demonstrate the issue? This makes it so much easier to take a look into the issue, thank you!

[DosCervezas]

thanks for your reply hahmed but I rerolled my own branch days ago sorry
but the lines I mention to pass the reason to the close event of the websocket are in this file available
https://github.com/rails/rails/blob/main/actioncable/app/javascript/action_cable/connection.js

the reason is logged in line 138 but not passed further. Thats my problem.. and globaly overwritting the log function to get the reason is not the right way I guess...

[hahmed]

I'm not sure that's the way to go, I mean you can use the logger for logging too, but maybe you want something like this https://guides.rubyonrails.org/action_cable_overview.html#server-side-components-channels-exception-handling

Handle the exception then broadcast the error message to another channel that displays errors in a modal/alert/banner or something? (been a while since I used action cable, so I would need to test it)

[hahmed]

I did a quick test and managed to broadcast an error message to another channel, something along the lines of ErrorAlertChannel.broadcast_to("error", exception.message) this will allow the subscriber to handle the error client side.

I'm closing this because I don't think this is an issue.