PubNub subscribe message callback not firing - angularjs

Question

I'm having issues getting PubNub's subscribe message handler to fire. I'm working on a web client that will listen for messages from mobile apps. Up until recently, this code worked fine. I could send a message from my phone and see the web app get auto-updated. But in the last few days, the web app is no longer getting updated.
It's an Angular app that I've been writing in CoffeeScript. I have a MessageService that handles all the bootstrapping for PubNub. The subscribe method of my service is passed an entity id arg to set as the channel name to listen on, and passes a function reference via the messageHandler argument.
angular.module('exampleApp').service 'MessageService', ($http, $interval) ->
pubnub = null
subscribePromise = null
config =
subscribe_key: 'demo'
# Sanity check. This gets triggered upon connection with the correct
# channel name/entity id.
connectionHandler = ->
_.forOwn arguments, (arg) -> console.log arg
return {
getChats: (id) ->
# Calls an API to fetch all of the chat messages. These aren't transmitted over
# PubNub because we do other fun things to adhere to HIPAA compliance.
return $http.get 'path/to/api/endpoint/' + id
subscribe: (id, messageHandler) ->
pubnub = pubnub or PUBNUB.init config
pubnub.subscribe({
channel: id
message: (data) ->
if not not subscribePromise
$interval.cancel subscribePromise
subscribePromise = null
messageHandler data
connect: connectionHandler
})
# Interval-based workaround to function in spite of PubNub issue
subscribePromise = $interval messageHandler, 10000
}
Here's an example of the messageHandler implementation in one of my controllers.
angular.module('exampleApp').controller 'MessageCtrl', (MessageService) ->
$scope.messageId = 'some entity id'
# This message handler never gets fired, despite passing it to pubnub.subscribe
onMessageUpdated = (data) ->
console.log data
MessageService.getChats($scope.messageId).then (messages) -> $scope.messages = messages
MessageService.subscribe $scope.messageId, onMessageUpdated
Like I mentioned, this code was working not long ago, but out of the blue, the message handler stopped firing at all. Haven't touched it in more than a month. The thing that's driving me nuts is that I can open up the dev console in PubNub and watch the messages come in from the phones, but for some reason, that message handler never seems to get called.
I'm using the "edge" version of pubnub.js, so I'm wondering if there was some recent update that broke my implementation. Anything else you folks can see that I may be missing or doing wrong? Any help is appreciated.
// Edit
Just a quick update. I've tried rolling back as far as 3.5.47 and still no change in behavior. I coded a quick workaround using Angular's $interval service to allow the app to at least function while I get this issue figured out. Updated code example above w/ relevant changes.

Answer 1

Quick update. After moving on to some other tasks and circling back to this after a year or so, we decided to take another stab at the problem. The interval-based polling was working fine for our initial implementation as described above, but we now have need for a more robust set of features.
Anyway, we ended up grabbing the latest stable version of the JS client (3.7.21), and so far it appears to have fixed our issue.