ClassPropertiesAfter.jsx

class MyComponent extends React.Component {
    static propTypes = {
        photoUrl: PropTypes.string,
        initialButtonVisible: PropTypes.bool
    };

    static defaultProps = {
        photoUrl: '',
        initialButtonVisible: true
    };

    state = {
        photoVisible: this.props.initialPhotoVisible
    };

    togglePhotoVisible = () => {
        this.setState({
            photoVisible: !this.state.photoVisible;
        });
    };

    render() {
        return (
            <div>
                <button onClick={this.togglePhotoVisible}>
                    {this.state.photoVisible ? 'Hide' : 'Show'} photo
                </button>
                {this.state.photoVisible && <img src={this.props.photoUrl}} />}
            </div>
        );
    }
}