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30 lines
742 B
30 lines
742 B
"use strict";
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exports.__esModule = true;
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exports.default = useRefWithInitialValueFactory;
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var _react = require("react");
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var dft = Symbol('default value sigil');
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/**
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* Exactly the same as `useRef` except that the initial value is set via a
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* factroy function. Useful when the default is relatively costly to construct.
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*
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* ```ts
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* const ref = useRefWithInitialValueFactory<ExpensiveValue>(() => constructExpensiveValue())
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*
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* ```
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*
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* @param initialValueFactory A factory function returning the ref's default value
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* @category refs
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*/
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function useRefWithInitialValueFactory(initialValueFactory) {
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var ref = (0, _react.useRef)(dft);
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if (ref.current === dft) {
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ref.current = initialValueFactory();
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}
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return ref;
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} |