If another piece of code calls $scope.$on, I'd like my service to be notified of this so it can subscribe to a websocket with the same named channel. Is there an event on $rootScope that I can listen for or an expression I can $watch?
I tried this: http://jsfiddle.net/polidore/AZ7Av/
Where I'm $watching Object.keys($scope.$$listeners).length, but it doesn't seem to get called aside from the initial load.
Thanks!
Instead of calling $on, the best way is to make your own function which calls $on for you while notifying your service.
If you you really need to detect it via the $on function, then you can override the function like this:
var old$on = $scope.$on;
$scope.$on = function(name, listener) {
// Code to notify your service here
old$on.apply(this, arguments);
}