Q:

React - Change state in child component

I trying to change my state in another component. I have passed the state by props
  constructor(props) {
    super(props);

      this.handleClick = this.handleClick.bind(this);  

      this.state = {
          isOpen: false
      };  
  } 

<MobileContent isOpen={this.state.isOpen} />

In my MobileContent component i want to change the state when i click on the element. 
class MobileContent extends Component {

  render() {
    if (this.props.isOpen) {
        return (
            <Grid fluid>
                <div className="mobileContent">
                <Row center="xs">
                    <Col xs={12}>
                    <span className="button">Hello, world!</span>
                    <span className="close" onClick={this.handleClick} >X</span>              
                    </Col>                 
                </Row>
                </div>
            </Grid>
        );
    }
    return null;
  }
}

export default MobileContent;

Thanks for the help !! 

A:

If you want the Child component to notify the parent, then you should pass an additional prop down to the child which is a function. The child can then call that. So in the parent:
constructor(props) {
    super(props);

    this.handleClick = this.handleClick.bind(this);  

    this.state = {
        isOpen: false
    };  
} 

<MobileContent isOpen={this.state.isOpen} onClose={this.handleClick}/>

And in the child:
render() {
    if (this.props.isOpen) {
        return (
            <Grid fluid>
                <div className="mobileContent">
                <Row center="xs">
                    <Col xs={12}>
                    <span className="button">Hello, world!</span>
                    <span className="close" onClick={this.props.onClose}>X</span>              
                    </Col>                 
                </Row>
                </div>
            </Grid>
        );
    }
    return null;
  }

