React State with Backing Instance Example

react-instance-backed-state-example.tsx

class MessageForm extends React.Component<Props, State> {
  constructor(props: Props) {
    super(props);

    this.state = {
      message: '',
    };
  }

  render() {
    const { submitMessage } = this.props;

    return (
      <form onSubmit={e => {
        e.preventDefault();
        submitMessage(this.state.message);
      }}>
        <input
          type="text"
          onChange={e => this.setState({
            message: e.currentTarget.value,
          })}
        />
        <input
          type="submit"
          value="Add"
        />
      </form>
    );
  }
}