Dartpad html - 如何在重新运行时删除事件监听器？

Question

In Dartpad with html ( https://dartpad.dev/html ), I am experimenting with the following code snippet:

import 'dart:html';

void main() {
  final header = querySelector('#header');
  header?.text = "Hello, World!";
  
  var streamobject = document.onSelectionChange.listen(handleSelectionChange);
  
  // streamobject.cancel() when re-run
  
}

void handleSelectionChange(Event e) {
  // do sth with range
}

However, when I run this code snippet again, the event listener from the previous run is not detached. Unfortunately, it seems that it is not possible to access the Run button in Dartpad and do something like this:

ButtonElement btn = querySelector('#run-button');
btn.onClick.listen((event) => streamobject.cancel());

Is there a way to delete all event listeners from document upon re-execution in dartpad?

Answer 1

A page refresh cleaning cache does the job ( Cmd + Shift + R on Mac, or Ctrl + F5 on Windows).