i have a page on which there an event handler attached to an onclick event. when the event fires it passes contents of a textbox to a GET request. since the url is not in the same domain so i create a script tag and and attach the url to its source like this

elem.onclick=fire;

function fire()
{
var text=document.getElementById('text').value;
var script=document.createElement("script");
script.className="temp";
script.src="some url"+"?param="+text;
document.body.appendChild(script);
}

now if that event is fired and more than one time i want to cancel all the previous GET request(because they still might be receiving response) and make the GET request with latest text. But for this i need to cancel the previous requests. i tried

document.body.removeChild(script);
script.src=null;

but this does not work in Firefox(i am using Firefox 5) although this works in Google Chrome.Does anyone know if these requests can be cancelled in Firefox and if yes then how?

UPDATE As suggested by Alfred, i used window.stop to cancel a request but does not cancel a request but hangs it up. It means that when i look into firebug it looks like the request is being made but there is no response.

i have a page on which there an event handler attached to an onclick event. when the event fires it passes contents of a textbox to a GET request. since the url is not in the same domain so i create a script tag and and attach the url to its source like this

elem.onclick=fire;

function fire()
{
var text=document.getElementById('text').value;
var script=document.createElement("script");
script.className="temp";
script.src="some url"+"?param="+text;
document.body.appendChild(script);
}

now if that event is fired and more than one time i want to cancel all the previous GET request(because they still might be receiving response) and make the GET request with latest text. But for this i need to cancel the previous requests. i tried

document.body.removeChild(script);
script.src=null;

but this does not work in Firefox(i am using Firefox 5) although this works in Google Chrome.Does anyone know if these requests can be cancelled in Firefox and if yes then how?

UPDATE As suggested by Alfred, i used window.stop to cancel a request but does not cancel a request but hangs it up. It means that when i look into firebug it looks like the request is being made but there is no response.

• javascript
• events
• firefox
• dom
• request-cancelling

• Would you consider using a library like jQuery? – Matt Ball Commented Jul 28, 2011 at 21:02
• 1 @Matt Ball i certainly would. but can u also suggest plain javascript bcoz i want to understand how its done? – lovesh Commented Jul 28, 2011 at 21:08
• 1 I did a search on stackoveflow. and found the [following answer][1] [1]: stackoverflow./questions/117551/… – Alfred Commented Aug 1, 2011 at 7:28
• @Alfred hey thanks a lot but u knw when i checked in firefug's net panel the request seems to have hung up and not cancelled actually and i cannot make any other requests too – lovesh Commented Aug 1, 2011 at 7:42
• @Alfred can i cancel a particular hung up request? – lovesh Commented Aug 1, 2011 at 7:54

5 Answers 5

The solution is simple: for creating HTTP requests, use <img> instead of <script> element. Also you always have to change the src attribute of the same element.

var img;
function fire()
{
    var text = document.getElementById('text').value;
    var im = img || (img = new Image());
    im.src = "url"+"?param="+text;
}

You may ascertain that it actually works by doing the following: the URL you request should have a huge response time (you can ensure this using e.g. PHP's sleep function). Then, open Net tab in Firebug. If you click the button multiple times, you'll see that all inplete requests are aborted.

This is entirely shooting from the hip, but if the script tag has not finished loading you can probably simply script.parentElement.removeChild( script ). That is more or less what mootools does anyway. (Technically, they replace /\s+/ with ' ' first, but that does not seem to be terribly important).

Would it be ok for you to use a JS framework? If so, MooTools has this functionality built into its Request.JSONP object

I'm not sure if this is what you're looking for, but it seems like a similar issue: http://www.velocityreviews./forums/t506018-how-to-cancel-http-request-from-javascript.html

To get around the cross-domain issue, you might be able to use CORS instead (assuming you can change what's on the server): http://hacks.mozilla/2009/07/cross-site-xmlhttprequest-with-cors/

If you do this, you could then use the more standard XMLHttpRequest's abort() function.

CORS is patible with all the major modern browsers except Opera (http://caniuse./cors).