如何在React.js中执行debounce ?

我想撤消handleOnChange。

我尝试debounce(这。handleOnChange, 200)但它不起作用。

function debounce(fn, delay) {
  var timer = null;
  return function() {
    var context = this,
      args = arguments;
    clearTimeout(timer);
    timer = setTimeout(function() {
      fn.apply(context, args);
    }, delay);
  };
}

var SearchBox = React.createClass({
  render: function() {
    return <input type="search" name="p" onChange={this.handleOnChange} />;
  },

  handleOnChange: function(event) {
    // make ajax call
  }
});

当前回答

您可以使用Lodash debounce https://lodash.com/docs/4.17.5#debounce方法。它简单有效。

import * as lodash from lodash;

const update = (input) => {
    // Update the input here.
    console.log(`Input ${input}`);     
}

const debounceHandleUpdate = lodash.debounce((input) => update(input), 200, {maxWait: 200});

doHandleChange() {
   debounceHandleUpdate(input);
}

您还可以使用下面的方法取消debounce方法。

this.debounceHandleUpdate.cancel();

希望对你有所帮助。干杯! !

其他回答

现在,React和React Native在2019年底有了另一个解决方案:

react-debounce-component

<input>
<Debounce ms={500}>
  <List/>
</Debounce>

它是一个组件,易于使用,体积小,支持广泛

例子:

import React from 'react';
import Debounce from 'react-debounce-component';

class App extends React.Component {
  constructor (props) {
    super(props);
    this.state = {value: 'Hello'}
  }
  render () {
    return (
      <div>
        <input value={this.state.value} onChange={(event) => {this.setState({value: event.target.value})}}/>
        <Debounce ms={1000}>
          <div>{this.state.value}</div>
        </Debounce>
      </div>
    );
  }
}

export default App;

我是这个组件的创建者

今天遇到了这个问题。使用setTimeout和clearTimeout解决。

我将给出一个你可以适应的例子:

import React, { Component } from 'react'

const DEBOUNCE_TIME = 500

class PlacesAutocomplete extends Component {
  debounceTimer = null;

  onChangeHandler = (event) => {
    // Clear the last registered timer for the function
    clearTimeout(this.debounceTimer);

    // Set a new timer
    this.debounceTimer = setTimeout(
      // Bind the callback function to pass the current input value as arg
      this.getSuggestions.bind(null, event.target.value), 
      DEBOUNCE_TIME
    )
  }

  // The function that is being debounced
  getSuggestions = (searchTerm) => {
    console.log(searchTerm)
  }

  render() {
    return (
      <input type="text" onChange={this.onChangeHandler} />
    )
  }
}

export default PlacesAutocomplete

你也可以在它自己的函数组件中重构它:

import React from 'react'

function DebouncedInput({ debounceTime, callback}) {
  let debounceTimer = null
  return (
    <input type="text" onChange={(event) => {
      clearTimeout(debounceTimer);

      debounceTimer = setTimeout(
        callback.bind(null, event.target.value), 
        debounceTime
      )
    }} />
  )
}

export default DebouncedInput

像这样使用它:

import React, { Component } from 'react'
import DebouncedInput from '../DebouncedInput';

class PlacesAutocomplete extends Component {
  debounceTimer = null;

  getSuggestions = (searchTerm) => {
    console.log(searchTerm)
  }

  render() {
    return (
      <DebouncedInput debounceTime={500} callback={this.getSuggestions} />
    )
  }
}

export default PlacesAutocomplete

与其在debounce()中包装handleOnChange,不如在debounce()中包装回调函数中的ajax调用,从而不破坏事件对象。就像这样:

handleOnChange: function (event) {
   debounce(
     $.ajax({})
  , 250);
}

您可以使用引用变量来存储计时器,然后将其清除。下面是一个不使用任何第三方包在react中实现deboundation的例子

import { useState, useRef } from "react";
import "./styles.css";

export default function App() {
  // Variables for debouncing
  const [text, setText] = useState("");
  const timer = useRef();

  // Variables for throtteling
  const [throttle, setThrottle] = useState(false)


  const handleDebouncing = ({ target }) => {
    clearTimeout(timer.current)

    timer.current = setTimeout(() => {
      callApi();
    }, 300);

    setText(target.value);
  };

  const handleThrottleing = () => {
    callApi()

    setThrottle(true)

    setTimeout(() => {
      setThrottle(false)
    }, 2000)
  }

  const callApi = () => {
    console.log("Calling Api");
  };

  return (
    <div className="App">
      <input type="text" onChange={handleDebouncing} />

      <button onClick={handleThrottleing} disabled={throttle} >Click me to see throtteling</button>
    </div>
  );
}

不受控制的组件

你可以使用event.persist()方法。

下面是一个使用下划线_.debounce()的例子:

var SearchBox = React.createClass({

  componentWillMount: function () {
     this.delayedCallback = _.debounce(function (event) {
       // `event.target` is accessible now
     }, 1000);
  },

  onChange: function (event) {
    event.persist();
    this.delayedCallback(event);
  },

  render: function () {
    return (
      <input type="search" onChange={this.onChange} />
    );
  }

});

编辑:请看这个JSFiddle


控制组件

更新:上面的例子显示了一个不受控制的组件。我一直在使用受控元素,这里是上面的另一个例子,但没有使用event.persist()“欺骗”。

JSFiddle也是可用的。不带下划线的示例

var SearchBox = React.createClass({
    getInitialState: function () {
        return {
            query: this.props.query
        };
    },

    componentWillMount: function () {
       this.handleSearchDebounced = _.debounce(function () {
           this.props.handleSearch.apply(this, [this.state.query]);
       }, 500);
    },

    onChange: function (event) {
      this.setState({query: event.target.value});
      this.handleSearchDebounced();
    },

    render: function () {
      return (
        <input type="search"
               value={this.state.query}
               onChange={this.onChange} />
      );
    }
});


var Search = React.createClass({
    getInitialState: function () {
        return {
            result: this.props.query
        };
    },

    handleSearch: function (query) {
        this.setState({result: query});
    },

    render: function () {
      return (
        <div id="search">
          <SearchBox query={this.state.result}
                     handleSearch={this.handleSearch} />
          <p>You searched for: <strong>{this.state.result}</strong></p>
        </div>
      );
    }
});

React.render(<Search query="Initial query" />, document.body);

编辑:更新示例和JSFiddles到React 0.12

编辑:更新的例子,以解决Sebastien Lorber提出的问题

编辑:更新的jsfiddle不使用下划线和使用纯javascript debounce。