Add keyframes for multiple selected frames and adjust symbol transparency to 0

[Chaint]

an.getDocumentDOM().getTimeline().convertToKeyframes();
an.getDocumentDOM().setInstanceAlpha(0);

The above code does not seem to be able to complete the requirements

[Vladin M. Mitov]

If you describe in a little more detail what exactly you want to do, perhaps we can give you some meaningful advice.

[Chaint]

I would like to use a command to automatically add keyframes with 0 transparency for multiple frames

[Chaint]

[kglad]

you have to select an object to apply setinstancealpha.  ie, loop thought the objects on those frames.

[Chaint]

Multiple objects selected

[kglad]

not with that code

[Vladin M. Mitov · Accepted solution]

Yes, @kglad  is correct, you need to have a selection in order to execute setInstanceAlpha().
Immediately after executing convertToKeyframes(), there is no valid selection because we are in brand new keyframes. You can check this by using:

an.getDocumentDOM().getTimeline().convertToKeyframes();
an.trace( "selection: " + an.getDocumentDOM().selection );

Therefore, after creating the keyframes, select all elements within them.
Something like this:

var doc = fl.getDocumentDOM();
var tml = doc.getTimeline();
var frameSel = tml.getSelectedFrames();
tml.convertToKeyframes();

doc.selectNone();
for( var i = 0; i < frameSel.length; i+=3 ){
	var xlayer = tml.layers[ frameSel[i] ];
	var frm = xlayer.frames[ frameSel[i+1] ];
	if( ! frm ) continue;
	for( var j = 0; j < frm.elements.length; j++ ){
		frm.elements[j].selected = true;
	}
}
doc.setInstanceAlpha(0);