How to dispatch an action on load?

class App extends Component {
  componentDidMount() {
    this.props.fetchData();
  }

  render() {
    return this.props.isLoaded ? <div>{'Loaded'}</div> : <div>{'Not Loaded'}</div>;
  }
}

const mapStateToProps = (state) => ({
  isLoaded: state.isLoaded,
});

const mapDispatchToProps = { fetchData };

export default connect(mapStateToProps, mapDispatchToProps)(App);