support abortcontroller / abortsignal to all event handler / life hooks

[jimmywarting]

Describe the problem

when leaving the current page in a SPA, i would like to clean things up myself, using onDestroy works great for such wonders.
But if i'm finish with that listener that i have added then i would also like to remove that event listener also.

I think it's complicated to learn all new non-standard event handler that all frameworks try to re-invent... ideally i would just simply want to have a standard EventTarget instead that do support the { once, signal } options as a third argument.

being able to use abortController would help tremendously. even for fetching data that needs to be used on a particular page.

Describe the proposed solution

import { onDestroy } from 'svelte'

const ctrl = new AbortController()
const signal = ctrl.signal

signal.addEventlistener('abort', {
  elm.remove()
  elm = null // remove a element since we don't need it anymore
}, { once: true, signal })

something.addEventlistener('keyup', evt => {
  if (evt.key === 'escape') {
    ctrl.abort()
  }
}, { signal })

// unless this listener isn't removed it will still keep a references to some
// variable and prevent garbage collection if the added listener can't be removed...
onDestroy(() => { 
  elm.remove() // Error: can't call remove() of null
}, { signal}) // <-- add support for this

Importance

would make my life easier

[dummdidumm]

I don't understand the problem statement nor the code snippet. What's stopping you from calling the abort controller manually? What does elm refer to, and why are you imperatively interacting with it instead of using Svelte's declarative templating?

[paoloricciuti]

Closing since no reproduction was provided but feel free to reopen if you are still experiencing issues and can provide a reproduction.