Detecting failure to share on FB (also - why doesn't this work on Safari / iOS?)

[tomryanx]

Is there a way to detect failed share? This way I could at least pop up a modal so my users can manually copy & paste.

Also... I realise a lot of folks have already asked similar questions, but I've just a whole day trying to figure out why this doesn't work on iOS. All the fb js sdk docs say this works on mobile, specifically Safari on iOS.

Clue, anyone!?