How to check which subclass is the event fired? - dart

Question

I know event.type in DOM. I can parse for example mouseup, keydown, touchstart and so on. But how can I check for the event subclass? Like MouseEvent, AnimationEvent or ClipboardEvent? Can I use the event.type property?

Answer 1

You can check the class like
void myHandler(Event e) {
if(e is MouseEvent) {
print('Mouse');
} else if(e is AnimationEvent) {
print('Animation');
} else if(e is KeyboardEvent) {
print('Keyboard');
}
}

Answer 2

Since JavaScript is a prototype-based language you can to do it a bit strangely using Object.prototype.toString.call() and then cleaning up the result a little, like this:
var button = document.getElementById("testEvent");
button.onclick = function(e) {
console.log(
Object.prototype.toString.call(e).replace(/^\[object ([^\]]*)\]/, "$1")
);
}
This fiddle shows it in action - http://jsfiddle.net/SrmGJ/1/ working for me in FireFox. It should output "MouseEvent" in the fiddle, but if you hook it up to some of the other events, you will see different results.
Another method would be to call EventType.prototype.isPrototypeOf(e) for each of the types:
...
if (MouseEvent.prototype.isPrototypeOf(e)) { console.log("MouseEvent"); }
if (AnimationEvent.prototype.isPrototypeOf(e)) { console.log("AnimationEvent"); }
if (KeyboardEvent.prototype.isPrototypeOf(e)) { console.log("KeyboardEvent"); }
...
But that would look pretty nasty IMHO.