Checking if JavaScript is loaded in an Ajax call?

Question

I am adding a JavaScript file to my site (using appendChild) in an Ajax calls oncomplete. After that I am trying to call a function that is included in that file. Like this:

// append the JS to the head
document.getElementsByTagName('head')[0].appendChild(element);

// call a function that is contained in the js file
myFunction();

The call to myFunction says "myFunction() is not defined". The question is, how do I know when it is defined?

Thanks!

http://stackoverflow.com/questions/6725272/dynamic-cross-browser-script-loading — Prinzhorn, Jun 04 '13 at 15:55

score 1 · Accepted Answer · answered Jun 04 '13 at 15:55

1

you can do

if (myfunction != undefined)
{
}

Also to make sure it's a function you can add this

if(typeof (window.myFunction) == ‘function’) {

answered Jun 04 '13 at 15:55

Smeegs

9,151
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1

Your first example will throw an error if myfunction is undefined. The second one is better :-) – Dziad Borowy Jun 04 '13 at 16:06

score 1 · Answer 2 · answered Jun 04 '13 at 15:55

1

You can use onload to find out when it's complete.

var s = document.createElement('script');
 s.onreadystatechange = s.onload = function() {
    var state = s.readyState;

    if (!callback.done && (!state || /loaded|complete/.test(state))) {
        // done!
    }
};
s.src = "myurl/myscript.js";
document.getElementsByTagName('head')[0].appendChild(s);

answered Jun 04 '13 at 15:55

Gabe

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One word: **IE**: http://stackoverflow.com/questions/6725272/dynamic-cross-browser-script-loading – Prinzhorn Jun 04 '13 at 15:56

Checking if JavaScript is loaded in an Ajax call?

2 Answers2