TextInput - React

문제

풀이

// React is loaded and is available as React and ReactDOM
// imports should NOT be used
class Input extends React.PureComponent {
  render() {
    let {forwardedRef, ...otherProps} = this.props; 
    return <input {...otherProps} ref={forwardedRef} />;
  }
}

const TextInput = React.forwardRef((props, ref) => {
  return <Input {...props} forwardedRef={ref} />
});

class FocusableInput extends React.Component {
  
  ref = React.createRef()

  render() {
    return <TextInput ref={this.ref} />;
  }

  // When the focused prop is changed from false to true, 
  // and the input is not focused, it should receive focus.
  // If focused prop is true, the input should receive the focus.
  // Implement your solution below:
  componentDidUpdate(prevProps) {
    if(prevProps.focused != this.props.focused && this.props.focused){
      this.ref.current.focus();
    }
  }

  componentDidMount() {
    if(this.props.focused){
      this.ref.current.focus();
    }
  }

}

FocusableInput.defaultProps = {
  focused: false
};

const App = (props) => <FocusableInput focused={props.focused} />;

document.body.innerHTML = "<div id='root'></div>";
const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);