CODE EXAMPLE FOR JAVASCRIPT

update parent state from child react

class Parent extends React.Component {
    constructor(props) {
        super(props)

        // Bind the this context to the handler function
        this.handler = this.handler.bind(this);

        // Set some state
        this.state = {
            messageShown: false
        };
    }

    // This method will be sent to the child component
    handler(id) {
        this.setState({
            messageShown: true,
            id: id
        });
    }

    // Render the child component and set the action property with the handler as value
    render() {
        console.log(this.state);
        return (
           <div>
              <Child action={this.handler} />
              <div>{this.state.id}</div>
           </div>
        );
    }
}

class Child extends React.Component {
    render() {
        return (
            <div>
                {/* The button will execute the handler function set by the parent component */}
                <button onClick={() => this.props.action(1)} > button </button>
            </div>
        )
    }
}
ReactDOM.render(<Parent />, document.getElementById('main'));