Angularjs wrapper for socket.io

socketio.js

admin.factory('$socket', ['$rootScope', function ($rootScope) {
  if (typeof io != 'undefined')
    var socket = io.connect();
  return {
    connect: function (url) {
      if (typeof io != 'undefined')
        socket = io.connect(url);
    },
    on: function (eventName, callback) {
      if (typeof socket != 'undefined')
        socket.on(eventName, function () {  
          var args = arguments;
          $rootScope.$apply(function () {
            callback.apply(socket, args);
          });
        });
    },
    emit: function (eventName, data, callback) {
      if (typeof socket != 'undefined')
        socket.emit(eventName, data, function () {
          var args = arguments;
          $rootScope.$apply(function () {
            if (callback) {
              callback.apply(socket, args);
            }
          });
        })
    }
  };
}]);