anki/ts/graphs/asyncRefresh.ts

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import { Readable, readable, derived } from "svelte/store";
interface AsyncRefreshData<T, E> {
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value: Readable<T | null>;
error: Readable<E | null>;
pending: Readable<boolean>;
success: Readable<boolean>;
loading: Readable<boolean>;
}
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function useAsyncRefresh<T, E>(
asyncFunction: () => Promise<T>,
dependencies: [Readable<unknown>, ...Readable<unknown>[]]
): AsyncRefreshData<T, E> {
const initial = asyncFunction();
const promise = derived(dependencies, (_, set) => set(asyncFunction()), initial);
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const value = derived(
promise,
($promise, set: (value: T | null) => void) => {
$promise.then((value: T) => set(value));
return () => set(null);
},
null
);
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const error = derived(
promise,
($promise, set: (error: E | null) => void) => {
$promise.catch((error: E) => set(error));
return () => set(null);
},
null
);
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const pending = readable(true, (set: (value: boolean) => void) => {
initial.finally(() => set(false));
});
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const loading = derived(
[value, error],
(_, set) => {
set(false);
return () => set(true);
},
true
);
const success = derived(
[value],
(_, set) => {
set(true);
return () => set(false);
},
false
);
return { value, error, pending, loading, success };
}
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export default useAsyncRefresh;