ht_hooks/es/useDebounceFn/index.js

ht React 业务 Hooks

import { __read, __spreadArray } from "tslib";
import { debounce } from '../utils/lodash-polyfill';
import { useMemo, useState, useEffect } from 'react';
import useLatest from '../useLatest';
import useUnmount from '../useUnmount';
import { isFunction } from '../utils';
import isDev from '../utils/isDev';
function useDebounceFn(fn, options) {
  var _a;
  if (isDev) {
    if (!isFunction(fn)) {
      console.error("useDebounceFn expected parameter is a function, got ".concat(typeof fn));
    }
  }
  var fnRef = useLatest(fn);
  var wait = (_a = options === null || options === void 0 ? void 0 : options.wait) !== null && _a !== void 0 ? _a : 1000;
  var debounced = useMemo(function () {
    return debounce(function () {
      var args = [];
      for (var _i = 0; _i < arguments.length; _i++) {
        args[_i] = arguments[_i];
      }
      return fnRef.current.apply(fnRef, __spreadArray([], __read(args), false));
    }, wait, options);
  }, []);
  useUnmount(function () {
    debounced.cancel();
  });
  return {
    run: debounced,
    cancel: debounced.cancel,
    flush: debounced.flush
  };
}
export default useDebounceFn;
//课上写法
var useDebounce2 = function (value, delay) {
  if (delay === void 0) {
    delay = 500;
  }
  var _a = __read(useState(value), 2),
    debouncedValue = _a[0],
    setDebouncedValue = _a[1];
  useEffect(function () {
    var timer = setTimeout(function () {
      setDebouncedValue(value); //一段时间value不变，取debouncedValue未最新的value
    }, delay);
    return function () {
      clearTimeout(timer);
    };
  }, [value, delay]); //#value更新时执行上一次的return（清楚上次定时器）和本次内容（新建定时器）
  return debouncedValue;
};
//setDebouncedValue(value) 触发了 setState，React 组件会重新渲染，useDebounce2 也会重新执行，return debouncedValue 会返回新的值