Question

I have an object for each room I’m joining with Strophe. This object contains a function for handling presence stanzas for this particular room.

function Room(name, someData)
    this.name = name;
    this.someData = someData;

    this.presenceHandler = function(presence) {
        console.log(this.name, this.someData);
    }

    this.join = function() {
        connection.addHandler(this.presenceHandler,null,"presence",null,null,this.name);
        connection.send(/*presence*/);
    }
}

var connection = new Strophe.Connection(/*http-bind*/);
var mainRoom = new Room("main", {foo: "bar"});
mainRoom.join();

But when the mainRoom.presenceHandler() function is called by an stanza by Strophe, this in the function refers to the stanza itself and not to mainRoom anymore, so I cannot access the attributes from mainRoom.

Could you tell me, how I can access the attributes of the room object from within the presenceHandler function?

Answer 1

        this.join = function() {
    connection.addHandler(this.presenceHandler,null,"presence",null,null,this.name);
    connection.send(/*presence*/);
}

Replace above code with this

        var thiss=this;
    this.join = function() {
    connection.addHandler(function(presence)             
    {thiss.presenceHandler(presence);},null,"presence",null,null,this.name);
    connection.send(/*presence*/);
}

note the closures for the handler