How To Get The Instance Name Of An Object

I use the below code to write code to query a web method in a specified interval. now in the this.Poll function I have to do this.tmo = setTimeout(this.strInstanceName + '.Poll()'

Solution 1:

Loose the parenthesis in this.Poll(). You call this function right away, not after a time interval. If you loose the brackets, it will pass a function, not a result of it, to setInterval and you won't have any issues.

setTimeout(this.Poll, this.Interval);

Otherwise you call the function right away and nothing holds this pointer anymore, and IE just deletes it.

In fixed variant, this.Poll will hold pointer to this and it won't be deleted.

Solution 2:

I just wanted to say, this self trick has saved me a ton of hair pulling.

I didn't think to create a reference like this. It means dynamically-created elements with on click events can call the correct instance of my class.

Solution 3:

You could also use:

i.e.

var name = findInstanceOf(cPoll);

function findInstanceOf(obj) {
    for (var v in window) {
        try {
            if (window[v] instanceof obj)
                return v;
        } catch(e) { }
    };
    return false;
}

From http://www.liam-galvin.co.uk/2010/11/24/javascript-find-instance-name-of-an-object/#read

Solution 4:

var self = this;
this.tmo = setTimeout(function(){
     self.Poll();
}, this.iInterval);

Solution 5:

I provided an answer for a similar question today in which I created a polling class from scratch. You may want to adopt it for yourself. In the sake of not duplicating, here's a link a link to said question:

Poll the Server with Ajax and Dojo *

* Despite the title, my solution offers both "vanilla" and Dojo styles.