在 ReactJs 中从父级复制道具？

Question

我正在使用 reactjs 16.

我正在制作一个向导，我正在尝试将它设计成可以在我需要的网站上的任何地方重复使用它。

这是我的代码

export default class App extends Component {
  constructor(props) {
    super(props);
  }

  render() {

    const steps = [ {name: 'Step 1', component:   <Step1 /> }, 
                    {name: 'Step 2', component:   <Step2 /> }];
    return (
      <React.Fragment>
            <WizardComponent  steps={steps}/>
      </React.Fragment>
    );
  }
}



import React, { Component } from "react";
import ReactDOM from "react-dom";


import WizardStepCompoent from "./WizardStepCompoent";


export default class WizardComponent extends Component {
  constructor(props) {
    super();
    this.state = {
      currentStep: 1
    };
  }
  next(e) {
    // need to update the current step look 
    // const step =  this.props.steps.find(x => x.name == "Step 1")
    // step.changeToCompleted() ----> go form {name: "Step 1",  component: <Step 1/>} to {name: "Step 1",  component: <Step 1/>, isCompleted: true}
  }
  render() {
    const props = this.props;
    return (
      <div>
        <div className="steps">
          {props.steps.map(step => {
            return <WizardStepCompoent step={step} />;
          })}
        </div>
         {props.steps.map(step => {
            return step.component; // later on use current state to figure out which one to render ie if currentStep == 1 then only render the 1st component 
          })} 


        <button onClick={ (e) => this.next(e) }>Next</button>
      </div>
    );
  }
}


export default class WizardStepCompoent extends Component {
    render() {
      const props = this.props;
      const step = props.step;
      var completed = "";
      if(step.isCompleted)
      {
          completed = "step-item is-completed";
      } else {
            completed = "step-item";
      }
      return (
        <div className={completed}>      
          <div className="step-marker">
            <span className="icon">
              <i className="fa fa-check" />
            </span>
          </div>
          <div className="step-details">
            <p className="step-title">{step.name}</p>
            <p>This is the first step of the process.</p>
          </div>
        </div>
      );
    }

Answer 1

要解决您正在做的事情，您需要克隆该元素并将适当的道具传递给它。 here is an example in a codepen to see it live

class App extends React.Component {
  render() {
    const steps = [ {id: 'first', name: 'Step 1', component:   <Step1 /> }, 
                    {id: 'second', name: 'Step 2', component:   <Step2 /> }];
    return (
      <div>
            <WizardComponent  steps={steps}/>
      </div>
    );
  }
}

class WizardComponent extends React.Component {
  constructor(props) {
    super();
    this.state = {
      currentStep: 0,
      completedSteps: {
        'first': {completed: false},
        'second': {completed: false}
      }
    };
  }
  next(e) {
    const {currentStep} = this.state
    const completedSteps = {...this.state.completedSteps}
    const current = this.props.steps[currentStep]
    completedSteps[current.id].completed = true
    this.setState({currentStep: this.state.currentStep + 1, completedSteps})
  }
  render() {
    const props = this.props;
    const {currentStep, completedSteps} = this.state
    return (
      <div>
        <div className="steps">
          {props.steps.map(step => {
            return <WizardStepCompoent step={step} />;
          })}
        </div>
         {props.steps.map((step, i) => {
            return React.cloneElement(step.component, completedSteps[step.id]); // later on use current state to figure out which one to render ie if currentStep == 1 then only render the 1st component 
          })} 


        <button onClick={ (e) => this.next(e) }>Next</button>
      </div>
    );
  }
}

正在发生的事情的实质是在克隆时以及当您按下下一步时。我在你的步骤中添加了一个 id 作为交叉引用每个步骤的一种方式，然后你通过它的 id 查找当前步骤并将 completed 设置为 true。这是一个相当基本的示例，所以请多多包涵。

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