We can set Parent State from Children Component in ReactJs using the following approach.
Prerequisite: State introduction in ReactJS
- We will actually set the state of a parent in the parent component itself, but the children will be responsible for setting.
- We will create a function in parent to set the state with the given input.
- We will pass that function in children as a prop.
- Then Children will call the function with a new Value.
- We will set the state of the parent in the function.
Creating React Application:
Step 1: Create a React application using the following command:
npx create-react-app foldername
Step 2: After creating your project folder, i.e., folder name, move to it using the following command:
cd foldername
Project Structure: It will look like the following.
Project Structure
Step 3: Now create Parent and Children components in the src folder with the following code.
Filename- Child.js:
Javascript
import React,{ Component } from 'react'; class Child extends Component { constructor(props) { super(props); this.handleClick.bind(this); } handleClick = () => { // We will start the process of changing // state of parent from Here... } render() { return ( <button onClick={this.handleClick}>Reveal Title</button> ); } } export default Child; |
Filename- Parent.js:
Javascript
import React,{ Component } from 'react'; import "./parent_css.css" // Importing child component for rendering import Child from './child'; class Parent extends Component { constructor(props) { super(props); this.state = {title: ""}; } render() { return ( <React.Fragment> // Rendering title of state initially empty. <h1> {this.state.title} </h1> // Rendering child component here which // contains only a button <Child /> </React.Fragment> ); } } export default Parent; |
Step 4: Create function setStateOfParent to set state of Parent in Parent component, also pass setStateOfParent function in children.
Filename- Parent.js:
Javascript
import React,{ Component } from 'react'; import "./parent_css.css" import Child from './child'; class Parent extends Component { constructor(props) { super(props); this.setStateOfParent.bind(this); this.state = {title: ""}; } // Creating below function to set state // of this (parent) component. setStateOfParent = (newTitle) => { this.setState({title: newTitle}); } render() { return ( <React.Fragment> <h1> {this.state.title} </h1> // Passing the setStateOfParent function // in child as a prop <Child setStateOfParent = {this.setStateOfParent}/> </React.Fragment> ); } } export default Parent; |
Step 5: Now access and call the setStateOfParent function in children whenever you want to set the state of the parent.
Filename- Child.js:
Javascript
import React,{ Component } from 'react'; class Child extends Component { constructor(props) { super(props); this.handleClick.bind(this); } handleClick = () => { // Simply call the setStateOfParent function from // prop and pass required argument this.props.setStateOfParent("Geeks For Geeks"); } render() { return ( <button onClick={this.handleClick}>Reveal Title</button> ); } } export default Child; |
Step to Run Application: Run the application using the following command from the root directory of the project:
npm start
Output: Now open your browser and go to http://localhost:3000/, you will see the following output:
