道具在同一组件内更新时如何运行功能?

时间:2019-10-22 16:35:49

标签: javascript html reactjs onchange react-props

我的一个组件中有一个名为transcript的道具。当我说出语音意图时,它会更新。我想随时随地运行一个函数,该函数将抄本作为参数

在这里,我尝试在将成绩单加载到的跨度内执行一个OnChange = {}函数,但是我知道此方法无效,这只是解释我要完成的工作的最简单方法


import React, { Component } from "react";
import SpeechRecognition from "react-speech-recognition";
import { Button } from 'react-bootstrap';


class Dictaphone extends Component {

highlightOnRead=(transcript, cursor)=>{

         console.log("transcript",transcript)
         console.log("cursor",cursor.anchorNode.parentNode.id) //we only need the word

         if(transcript.includes(" ")){
           transcript = transcript.split(" ").pop()
         }
         if(transcript = cursor.textContent.toLowerCase()){
             cursor.style.backgroundColor = 'yellow'; //highlight the span matching the intent
         }
         cursor = document.getElementById(cursor.anchorNode.parentNode.id).nextSibling.nextElementSibling;
               return cursor
     };



  render() {
   const {transcript, resetTranscript, browserSupportsSpeechRecognition} = this.props
    var cursor=''

    if (!browserSupportsSpeechRecognition) {
      return null
    }
    if(transcript==="notes"||transcript==="cards"||transcript==="home"|| transcript==="settings" || transcript==="read document"){
      this.libraryOfIntents(transcript,resetTranscript);
    }

    return (
      <div>
        <span id="transcriptSpan"className="transcriptspan" onChange={()=>{

          if(this.props.readAlongHighlightState===true){
            if(cursor===''){
              this.highlightOnRead(transcript,window.getSelection())
            }else{
                this.highlightOnRead(transcript,cursor)
            }
          }
        }}> {transcript}  </span>
        <Button variant="outline-dark" onClick={resetTranscript}>Reset</Button>
      </div>
    )
  }
}

export default SpeechRecognition(Dictaphone)

1 个答案:

答案 0 :(得分:0)

您可以使用称为componentDidUpdate的生命周期方法

componentDidUpdate(prevProps) {
  if (this.props.transcript !== prevProps.transcript) { // check if your props is changed
   // Make your function call here
  }
}