Question

I have a namespace object on which I have defined some functions. One of the functions is used to create a websocket session to a remote server.

ns.Session = function(url, config, callback){
   var ws = new WebSocket(url);
   ws.onmessage = function (e){
       if(login(e.data)){
           // This is the point at which I need to pass back the session object to callback
           callback(session):
       }
   }
   ....
}

In Javascript, as far as I know if someone invokes this function using ns.Session(....) then the this object will be ns. So, how do I get the instance of the “session” to send to the callback.
arguments.callee is deprecated as far as I know.

The whole reason I am doing it this way is that the session is not considered “usable” till the server confirms the login, so I don’t want to prematurely return the function object before it is actually connected and logged in. Hence the use of a callback. If there is a better way to achieve this, I am open to that too.

Session has a bunch of other inner functions like addHandler, sendData etc which I have not shown here for sake of brevity.

Answer 1

You can use pointer to function like this:

ns.Session = function session(...) {
    // 'session' here points to your function, so you do
    callback(session); // like you wrote
    callback(ns.Session); // same effect if you don't change ns and ns.Session pointers
}

Also, I don’t see why you use the word “instance” in this case, because functions have only one instance. If you call it with the ‘new’ keyword, function creates new object from the function, and now there you can use “instance” word.