React

by drowhunter

HTML

<div id="app"></div>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#app {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  transition: all 0.2s;
}

li {
  margin: 8px 0;
}

h2 {
  font-weight: bold;
  margin-bottom: 15px;
}

.done {
  color: rgba(0, 0, 0, 0.3);
  text-decoration: line-through;
}

input {
  margin-right: 5px;
}

React

class TodoApp extends React.Component {
  constructor(props) {
    super(props)
    this.state = {
    	items: [
      	{ text: "a", stuff: [ 1, 2, 3] },
        { text: "b", stuff: [ 4, 5 ] },
        { text: "c", stuff: [ 6, 7, 8] },
        { text: "d", done: true, stuff: [ 9, 0] }
      ],
			flatStuff: () => {
				return this.state.items.flatMap(m => m.stuff)
			}
    }
  }
  
  render() {
    return (
      <div>
        <h2>Todos:</h2>
        <ol>
        {this.state.flatStuff().map(item => (
          <li>{item}</li>
        ))}
        </ol>
      </div>
    )
  }
}

ReactDOM.render(<TodoApp />, document.querySelector("#app"))