53 lines
1.4 KiB
TypeScript
53 lines
1.4 KiB
TypeScript
// Copyright: Ankitects Pty Ltd and contributors
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// License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
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import { Readable, derived } from "svelte/store";
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interface AsyncReactiveData<T, E> {
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value: Readable<T | null>;
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error: Readable<E | null>;
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loading: Readable<boolean>;
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}
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function useAsyncReactive<T, E>(
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asyncFunction: () => Promise<T>,
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dependencies: [Readable<unknown>, ...Readable<unknown>[]],
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): AsyncReactiveData<T, E> {
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const promise = derived(
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dependencies,
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(_, set: (value: Promise<T> | null) => void): void => set(asyncFunction()),
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// initialize with null to avoid duplicate fetch on init
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null,
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);
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const value = derived(
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promise,
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($promise, set: (value: T) => void): void => {
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$promise?.then((value: T) => set(value));
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},
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null,
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);
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const error = derived(
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promise,
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($promise, set: (error: E | null) => void): (() => void) => {
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$promise?.catch((error: E) => set(error));
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return (): void => set(null);
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},
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null,
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);
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const loading = derived(
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promise,
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($promise, set: (value: boolean) => void): (() => void) => {
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$promise?.finally(() => set(false));
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return (): void => set(true);
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},
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true,
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);
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return { value, error, loading };
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}
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export default useAsyncReactive;
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