ghost-portal/packages/react-hooks/src/useMapKeys.ts

31 lines
884 B
TypeScript

// Copyright 2017-2021 @polkadot/react-hooks authors & contributors
// SPDX-License-Identifier: Apache-2.0
import type { QueryableStorageEntry } from '@polkadot/api/types';
import { useEffect, useState } from 'react';
interface Options <T> {
at?: string | null | false;
transform?: (value: any[]) => T[];
}
// FIXME This is generic, we cannot really use createNamedHook
export function useMapKeys <T = any> (entry?: QueryableStorageEntry<'promise'> | null | false, { at, transform }: Options<T> = {}): T[] | undefined {
const [state, setState] = useState<T[] | undefined>();
useEffect((): void => {
entry && (
at && at !== '0'
? entry.keysAt(at)
: entry.keys()
).then((keys) => setState(
transform
? transform(keys)
: keys as unknown as T[]
)).catch(console.error);
}, [at, entry, transform]);
return state;
}