What is the correct way to clean up (destroy) a socket

[lrice]

I am trying to destroy the socket on $scope.$destroy, but I am still having sockets stack up when closing/opening a modal. I have tried socket.disconnect() but still see polling. I have been shutting the local socketio server to make sure that reconnect errors stop after the scope is destroyed but they continue and stack every time I re-open the modal.

What is the proper way to close/disconnect and dispose of sockets when leaving the modal/route where they were used?

[davisford]

It is a little tricky with socket.io. Not sure what your needs are, but my app requires the socket to be torn down and thrown away on a logout, and a new one reconnected on a login. I've outlined how I do it in issue #86 along with a problem I have doing so with this library, and a workaround solution. Maybe it helps you?

[lrice]

Definitely, given that I'm not making use of the forwarding or scope broadcast features, I may just wrap the socket myself or fork this repo rather than modifying the source though. Thanks for the info though, its definitely good to know why this was occurring.

[redders6600]

Can you clarify how you are calling disconnect?

Exposing the socket's disconnect method via my service seems to work fine for me:

.factory('Socket', (socketFactory)->

  ioSocket = io.connect('/', {})

  socketFactory = socketFactory({ioSocket: ioSocket})
  socketFactory.disconnect = ()->
    ioSocket.disconnect()

  return socketFactory
)

In some controller:

.controller('SomeController', (Socket)->
  $scope.disconnect =-> Socket.disconnect()
)

[lrice]

My factory looks something like this:

.factory('Socket', ['socketFactory', function(Socket){

    return function(){
      var socket = io.connect('<URL>', {forceNew: true});
      return Socket({ioSocket:socket});
    };

}]);

And when I disconnect, I have tried

.controller('somecontroller',['$scope','Socket',
  function ($scope,Socket){
    $scope.socket = Socket();
   ...

    $scope.on('$destroy', function(){
        $scope.socket.disconnect();
        and
        $scope.socket.disconnect(true);
    };
};

Is there a difference between ioSocket and the disconnect exposed by socketFactory? Have you tried the situation where there isn't a current connection to the server? That was the main issue for me, if I shut down the server while the connection was active, and THEN tried to disconnect, I could not prevent it from retrying infinitely (other than to put a cap on retry attempts, etc). I will try your method when I get a chance and see if that has an affect on my situation, but I was afraid that it was just a symptom of something like what @davisford was describing.

[davisford]

@LukeRiceApperson I think I see your problem. You don't need to execute a fn/ctor on a dependency that is injected (like an angular service or factory). Angular already instantiates those for you.

So, I think your controller ought to instead be something like this:

.controller('somecontroller', ['$scope', 'Socket', function ($scope, Socket) {
    // isn't necessary to hang Socket off $scope unless you need to use it in an angular view expression
    $scope.socket = Socket;

    $scope.on('$destroy', function () {
      Socket.disconnect();
    });
}

That should work. There's another tip for debugging socket.io, run this in the console and then restart your app:

window.localStorage.debug = '*'; // that's an asterisk *

This will dump all kinds of debug info to the console on what socket.io / engine.io is doing.

[redders6600]

Is there a difference between ioSocket and the disconnect exposed by socketFactory?

Probably not - when I wrote that code this library wasn't exposing a disconnect method, so if it's implemented now it's likely the same.

I think @davisford has hit the nail on the head with regards to your problem.