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