is there any way to cancel a dart Future?

Question

In a Dart UI, I have a button [submit] to launch a long async request. The [submit] handler returns a Future. Next, the button [submit] is replaced by a button [cancel] to a

Answer 1

As far as I know, there isn't a way to cancel a Future. But there is a way to cancel a Stream subscription, and maybe that can help you.

Calling onSubmit on a button returns a StreamSubscription object. You can explicitly store that object and then call cancel() on it to cancel the stream subscription:

StreamSubscription subscription = someDOMElement.onSubmit.listen((data) {

   // you code here

   if (someCondition == true) {
     subscription.cancel();
   }
});

Later, as a response to some user action, perhaps, you can cancel the subscription: