javascript react
This is a formatted version of Komadori's answer
(https://tinyurl.com/Komadori)
React is a JavaScript library for building user interfaces.
It is maintained by Facebook and a community of
individual developers and companies.
React can be used as a base in the development of single-page
or mobile applications.
class TodoApp extends React.Component {
constructor(props) {
super(props);
this.state = { items: [], text: '' };
this.handleChange = this.handleChange.bind(this);
this.handleSubmit = this.handleSubmit.bind(this);
}
render() {
return (
<div>
<h3>TODO</h3>
<TodoList items={this.state.items} />
<form onSubmit={this.handleSubmit}>
<label htmlFor="new-todo">
What needs to be done?
</label>
<input
id="new-todo"
onChange={this.handleChange}
value={this.state.text}
/>
<button>
Add #{this.state.items.length + 1}
</button>
</form>
</div>
);
}
handleChange(e) {
this.setState({ text: e.target.value });
}
handleSubmit(e) {
e.preventDefault();
if (this.state.text.length === 0) {
return;
}
const newItem = {
text: this.state.text,
id: Date.now()
};
this.setState(state => ({
items: state.items.concat(newItem),
text: ''
}));
}
}
class TodoList extends React.Component {
render() {
return (
<ul>
{this.props.items.map(item => (
<li key={item.id}>{item.text}</li>
))}
</ul>
);
}
}
ReactDOM.render(
<TodoApp />,
document.getElementById('todos-example')
);
<!DOCTYPE html>
<html>
<script src="https://unpkg.com/react@16/umd/react.production.min.js"></script>
<script src="https://unpkg.com/react-dom@16/umd/react-dom.production.min.js"></script>
<script src="https://unpkg.com/[email protected]/babel.min.js"></script>
<body>
<div id="mydiv"></div>
<script type="text/babel">
class Hello extends React.Component {
render() {
return <h1>Hello World!</h1>
}
}
ReactDOM.render(<Hello />, document.getElementById('mydiv'))
</script>
</body>
</html>
