19 lines
531 B
JavaScript
19 lines
531 B
JavaScript
import { useRef } from 'react';
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/**
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* Creates a constant value over the lifecycle of a component.
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*
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* Even if `useMemo` is provided an empty array as its final argument, it doesn't offer
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* a guarantee that it won't re-run for performance reasons later on. By using `useConstant`
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* you can ensure that initialisers don't execute twice or more.
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*/
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function useConstant(init) {
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const ref = useRef(null);
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if (ref.current === null) {
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ref.current = init();
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}
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return ref.current;
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}
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export { useConstant };
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