Reverted load event is no longer fired on <iframe> with JavaScript src returning non-string value

Published: | Categories: DOM JavaScript


On Firefox 49, the load event is not fired on the <iframe> element when the source is JavaScript code that does not return a string, like this:

<iframe src="javascript:true" onload="alert('hello')"></iframe>

This change was made to follow the latest HTML spec, however, there are several reports of broken sites after the release of Firefox 49. Firefox 49.0.2 has therefore reverted the backward incompatible change so that the event will be fired as before.