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JavaScript React Components (2018) React Component Patterns Optimize Performance with PureComponent

Posted by Jane XU
Jane XU
3,153 Points

I think I write the same code as Guil, but all the players still being re-rendered everytime I clicked the counterbutton

code in Player.jsx

import React,{PureComponent} from "react";
import Counter from "./Counter";


class Player extends PureComponent {
  render() {
    console.log(this.props.name)
    return (  
    <div className="player">
    <span className="player-name">
    <button onClick={()=> {this.props.removePlayer(this.props.id)}} className="remove-player">✖</button>
    {this.props.name}
    </span>
    <Counter startPoint={this.props.startPoint} handleScore={this.props.handleScore} index={this.props.index}/>
  </div>
  );
  }
}

1 Answer

Tomas Schaffer
Tomas Schaffer
11,606 Points
Tomas Schaffer
Tomas Schaffer
11,606 Points

You dont setting props to class Player so your component cant read props from parrent component even if you are passing it. And you are tying also execute function from parrent component. Then you are passing this props to child component Counter which is also undifened.

class Player extends Component { constructor(props) { super(props); } render() { console.log(this.props.name) return (
<div className="player"> <span className="player-name"> <button onClick={()=> {this.props.removePlayer(this.props.id)}} className="remove-player">✖</button> {this.props.name} </span> <Counter startPoint={this.props.startPoint} handleScore={this.props.handleScore} index={this.props.index}/> </div> ); } }