Description
Describe the problem
There's a TODO in the codebase for making reactive maps and sets:
svelte/packages/svelte/src/internal/client/proxy/proxy.js
Lines 44 to 54 in 434a587
We could implement it, but there are several problems:
- we'd need to add the logic for making reactive map/set wrappers in a way that would be impossible to treeshake away for people who weren't using them
- that cost would increase if we wanted to add support for other built-ins (such as
Date, and possiblyWeakSetandWeakMap) — including future additions to the language - adding support for other built-ins couldn't be done without a breaking change necessitating a major version bump
- it wouldn't be totally clear which non-POJOs get the reactive treatment
- there's also no particularly good opt-out mechanism
Describe the proposed solution
Instead, we could just create our own wrappers:
<script>
import { Map } from 'svelte/reactivity';
const map = new Map();
map.set('message', 'hello');
function update_message() {
map.set('message', 'goodbye');
}
</script>
<p>{map.get('message')}</p>Importance
nice to have