setting the array to empty subscribe fails to subscribe.

[ayangweb]

export const store = proxy({
	arr: [1, 2, 3],
});

subscribe(store.arr, (value) => {
	// No output when array is empty
	console.log("value", value);
});

store.arr = [];

1. setting the array to empty subscribe fails to subscribe.
2. store is the persistent store [], which is still the default value [1, 2, 3] when the project starts.

[dai-shi]

store.arr = []; means you are mutating store not store.arr. So, you need to subscribe to store.

subscribe(store, () => {
	console.log("value", store.arr);
});

[ayangweb]

Ok, subscribe does work, so what should I do about the second question?

[dai-shi]

2. store is the persistent store [], which is still the default value [1, 2, 3] when the project starts.

Can you elaborate the question?

[ayangweb]

Well, the problem is also related to the fact that subscribe(store.arr) is not working!

Is there any other simple way to listen for changes when arr is empty? subscribe(store) is a bit complicated.

[dai-shi]

I don't the exact problem, but how about subscribeKey(store, 'arr', () => {})?

It's just a simple wrapper.

valtio/src/vanilla/utils/subscribeKey.ts

Lines 14 to 31 in e21edb3

	export function subscribeKey<T extends object, K extends keyof T>(
	proxyObject: T,
	key: K,
	callback: (value: T[K]) => void,
	notifyInSync?: boolean,
	): () => void {
	let prevValue = proxyObject[key]
	return subscribe(
	proxyObject,
	() => {
	const nextValue = proxyObject[key]
	if (!Object.is(prevValue, nextValue)) {
	callback((prevValue = nextValue))
	}
	},
	notifyInSync,
	)
	}

[ayangweb]

subscribeKey I've tested it, can't listen for changes to objects and arrays, only normal types of data!

[ayangweb]

Wait, subscribeKey seems to be working again, I'll get back to you when I verify it again!

[dai-shi]

even if it doesn't work for your case, you can do something similar and adjust for your case. underneath it's just subscribe.

[ayangweb]

The subscribeKey is working, but in Tauri development, since I'm using multiple windows, it's not possible for other windows to listen for changes via subscribeKey. Thanks for the heads up, I'll look into this further, thanks!