isPrototypeOf in indesign?

Question

Hi am relativly new to indesign scripting and would like to figure out if an object is a subtype of a class. Example: I want to iterate over all page items and take everything that is not a graphic: layer = app.activeDocument.layers[layerIndex]; for (i = 0; i < layer.allPageItems.length; i++) { alert(layer.allPageItems[i].reflect.name) if(layer.allPageItems[i].isPrototypeOf (Graphic) ) { alert("Graphic"); } else { .... } } howver the if nver matches. Are there any examples of how to use `isPrototypeOf`? What do I have to do to test if an object is of a certain type or a subclass of it? **edit**: To clarify, I am trying to test if I have an Instance of anything that _inherited_ from Graphic. But as far as I can see now that seems to be impossible.

Answer 1

isPrototypeOf() is a JavaScript method used to check whether an object exists in another object’s prototype chain.

It returns true if the object is a prototype of the specified object, otherwise false.

This method helps in understanding and verifying inheritance relationships between objects.

It is often more reliable than instanceof when dealing with complex prototype chains.