I had to show a loader while pdf in iFrame is loading so what i come up with:
loader({href:'loader.gif', onComplete: function(){
$('#pd').html('<iframe onLoad="loader.close();" src="pdf" width="720px" height="600px" >Please wait... your report is loading..</iframe>');
}
});
I'm showing a loader. Once I'm sure that customer can see my loader, i'm calling onCompllet loaders method that loads an iframe. Iframe has an "onLoad" event. Once PDF is loaded it triggers onloat event where i'm hiding the loader :)
The important part:
iFrame has "onLoad" event where you can do what you need (hide loaders etc.)