How to check if iframe is empty/null/undefined?

Question

This doesn\'t work:

if(document.getElementById(\"iframe\").innerHTML==\'\'){

Is there a safe browser reliable way to check an iframe if its

Answer 1

Well if you can use jQuery, check it's length property. This is cross-browser compatible. If it's zero, it doesn't exist. Something like this:

if(!$("#iframeid").length) {
    // iframe doesn't exist
}

EDIT:

After seeing your comments on your question:

If you want to check if no page loaded inside iframe, and the iframe is not cross-domain you could check for the existence of the body tag inside of the iframe. If it exists, then something loaded.

Something like this:

if($("#iframeid").contents().find("body").length) {
    // some html page loaded in iframe
}

If the iframe is cross-domain, you will be blocked by the same-origin policy. Otherwise this will work.