41 lines
1.9 KiB
JavaScript
41 lines
1.9 KiB
JavaScript
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"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.useEventCallback = void 0;
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var React = require("react");
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var useConst_1 = require("./useConst");
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var utilities_1 = require("@fluentui/utilities");
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/**
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* Modified `useCallback` that returns the same function reference every time, but internally calls
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* the most-recently passed callback implementation. Can be useful in situations such as:
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* - Event handler dependencies change too frequently, such as user props which might change on
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* every render, or volatile values such as useState/useDispatch
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* - Callback must be referenced in a captured context (such as a window event handler or unmount
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* handler that's registered once) but needs access to the latest props
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*
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* In general, prefer `useCallback` unless you've encountered one of the problems above.
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*
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* https://reactjs.org/docs/hooks-faq.html#how-to-read-an-often-changing-value-from-usecallback
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*
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* @param fn - The callback function that will be used
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* @returns A function which is referentially stable but internally calls the most recently passed callback
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*/
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function useEventCallback(fn) {
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var callbackRef = React.useRef(function () {
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throw new Error('Cannot call an event handler while rendering');
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});
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(0, utilities_1.useIsomorphicLayoutEffect)(function () {
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callbackRef.current = fn;
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}, [fn]);
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// useConst rather than useCallback to ensure the reference is always stable
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// (useCallback's deps list is an optimization, not a guarantee)
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return (0, useConst_1.useConst)(function () { return function () {
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var args = [];
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for (var _i = 0; _i < arguments.length; _i++) {
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args[_i] = arguments[_i];
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}
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var callback = callbackRef.current;
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return callback.apply(void 0, args);
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}; });
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}
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exports.useEventCallback = useEventCallback;
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//# sourceMappingURL=useEventCallback.js.map
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