zadanie04.jsx

import React from 'react';
import ReactDOM from 'react-dom';

document.addEventListener('DOMContentLoaded', function(){

    class ShowInfo extends React.Component {
        render() {
            return <h1>{ this.props.info }</h1>;
        }
    }

    class PropsToState extends React.Component {
        constructor(props) {
            super(props);

            this.state = {
                text: this.props.text,
            };
        }

        componentDidMount(){
            this.intervalId = setInterval(() => {
                this.setState({
                    text : this.state.text + '.',
                });
            }, 1000);
        }

        componentWillUnmount(){
            clearInterval( this.intervalId );
        }

        render() {
            return <ShowInfo info={this.state.text}/>
        }
    }

    class App extends React.Component {
        render(){
            return <PropsToState text="Sialalal" />;
        }
    }

    ReactDOM.render(
        <App />,
        document.getElementById('app')
    );
});