27 lines
724 B
TypeScript
27 lines
724 B
TypeScript
|
// Copyright: Ankitects Pty Ltd and contributors
|
||
|
|
// License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
|
||
|
|
|
||
|
|
import type { Readable, Subscriber, Unsubscriber } from "svelte/store";
|
||
|
|
|
||
|
|
/**
|
||
|
|
* In some cases, we only care for updates, and not the initial
|
||
|
|
* value of a store, e.g. when the store wraps events.
|
||
|
|
* This also means, we can not use the special store syntax.
|
||
|
|
*/
|
||
|
|
function subscribeToUpdates<T>(
|
||
|
|
store: Readable<T>,
|
||
|
|
subscription: Subscriber<T>,
|
||
|
|
): Unsubscriber {
|
||
|
|
let first = true;
|
||
|
|
|
||
|
|
return store.subscribe((value: T): void => {
|
||
|
|
if (first) {
|
||
|
|
first = false;
|
||
|
|
} else {
|
||
|
|
subscription(value);
|
||
|
|
}
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
export default subscribeToUpdates;
|