how to avoid that=this on JS using socket.io?

Question

This is my client JS script

var Chat = function(username) {

    that = this;            
    this.myUser = {"username":username};    
    this.socket = io(server);

    this.socket.on('connect', function(){   
        console.log(that.myUser);   // this is UGLY but this.myUser will give an error  
    });
}

any idea of how to get rid of that nasty "that = this" ?

use `self = this`... (just kidding) – Ivan Seidel Oct 31 '14 at 15:38 — Ivan Seidel, Oct 31 '14 at 15:38

Sirko · Accepted Answer · 2014-10-31T18:08:16.883

3

You could use bind():

var Chat = function(username) {

    this.myUser = {"username":username};    
    this.socket = io(server);

    this.socket.on('connect', function(){   
        console.log(this.myUser);
    }.bind( this ) );
};

But to be honest, I personally do not think, that this is much better.

edited Oct 31 '14 at 18:08

answered Oct 31 '14 at 15:30

Sirko

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@jfriend00 Good point ... to hasty an answer ... – Sirko Oct 31 '14 at 18:08
I suppose that I might ask why creating the closure on 'that' is such a bad or ugly thing? – Levi Beckman Oct 31 '14 at 18:41
@LeviBeckman I think both approaches are valid. Personally I use both based on the contents of the callback. – Sirko Oct 31 '14 at 19:05

how to avoid that=this on JS using socket.io?

1 Answers1