Question

Is it possible to cancel file upload that uses hidden iframe?

I’ve tried to set source of iframe to empty string, but upload haven’t been interrupted.

Answer 1

the iframe is the transport channel that is carrying the form posting, so Atanas is correct, you have to stop the transport inside the iframe.

here is a way of doing it depending on browser:

if (iframeObj.contentWindow.document.execCommand)
    { // IE browsers
        iframeObj.contentWindow.document.execCommand('Stop');
    }
else
    { // other browsers
        iframeObj.contentWindow.stop();
    }
// notify user upload was cancelled, remove spinner images, etc