单击按钮时将组件返回到 id

Question

I want to return a component <SaveTask/> to a div tag where <div id="saveTask"> . I tried to use this.setState() , but it changes the container and displays the <SaveTask/> component. I want to keep that container and under that container, I want to append a component after clicking a button. Is there any way to add component using document.getElementById('saveTask') .

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


export default class TaskHeader extends Component {

    constructor(props) {
        super(props)
        this.state = {
            saveTask: false,
        }

        this.showComp = () => {
            this.setState({
                saveTask: true,
            })
        }
    }

    render() {
        if(this.state.saveTask) {
            return (
                
                document.getElementById('saveTask').innerHTML = <SaveTask/>
                
            )
        }

        return (
            <div>
            <div className="container-fluid bg-white border-bottom">
                <div className="row">
                    <div className="col-12">
                        <div className="tasks-upper text-muted">TASK MANAGEMENT APP</div>
                        <div className="tasks-lower">
                            <span className="text-secondary text-size">TASK</span><button className="text-primary btn-size" type="button" onClick={this.showComp}>+</button>
                        </div>
                    </div>
                </div>
            </div>
            <div id="saveTask">
                Return a component to this section when clicking the button
            </div>
            </div>
        )
    }
}

Answer 1

Yeah, so the beauty of react is that you don't need to and shouldn't be updating the innerhtml to update a component. You can simply use a ternary to determine what component to show later on:

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


export default class TaskHeader extends Component {

    constructor(props) {
        super(props)
        this.state = {
            saveTask: false,
        }

        this.showComp = () => {
            this.setState({
                saveTask: true,
            })
        }
    }

    render() {
        return (
            <div>
            <div className="container-fluid bg-white border-bottom">
                <div className="row">
                    <div className="col-12">
                        <div className="tasks-upper text-muted">TASK MANAGEMENT APP</div>
                        <div className="tasks-lower">
                            <span className="text-secondary text-size">TASK</span><button className="text-primary btn-size" type="button" onClick={this.showComp}>+</button>
                        </div>
                    </div>
                </div>
            </div>
            {this.state.saveTask ? (
              <SaveTask/>
            ) : (
              <div id="saveTask">
                Return a component to this section when clicking the button
              </div>
            )}
            </div>
        )
    }
}

In this case you're saying, "if this.state.saveTask is true, then show <SaveTask /> otherwise, show the <div id="saveTask"> element. If you wanted inside that div, then you would just move the ternary inside it.

Answer 2

I hope following answer will help you

Achive using Functional Component

import React, { useState } from "react";
import SaveTask from "./SaveTask";

function TaskHeader() {
  const [show, setShow] = useState(false);

  const showComp = () => {
    setShow(true);
  };

  return (
    <div>
      <div className="container-fluid bg-white border-bottom">
        <div className="row">
          <div className="col-12">
            <div className="tasks-upper text-muted">TASK MANAGEMENT APP</div>
            <div className="tasks-lower">
              <span className="text-secondary text-size">TASK</span>
              <button
                className="text-primary btn-size"
                type="button"
                onClick={showComp}
              >
                +
              </button>
            </div>
          </div>
        </div>
      </div>
      <div id="saveTask">{show && <SaveTask />}</div>
    </div>
  );
}

export default TaskHeader;

Achive using Class Component

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


export default class TaskHeader extends Component {

    constructor(props) {
        super(props)
        this.state = {
            saveTask: false,
        }

        this.showComp = () => {
            this.setState({
                saveTask: true,
            })
        }
    }

    render() {
        return (
            <div>
            <div className="container-fluid bg-white border-bottom">
                <div className="row">
                    <div className="col-12">
                        <div className="tasks-upper text-muted">TASK MANAGEMENT APP</div>
                        <div className="tasks-lower">
                            <span className="text-secondary text-size">TASK</span><button className="text-primary btn-size" type="button" onClick={this.showComp}>+</button>
                        </div>
                    </div>
                </div>
            </div>
              <div id="saveTask">`
               { this.state.saveTask && <SaveTask/> }
              </div>
            </div>
        )
    }
}