React

by evgkch

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;
}

#wrapper {
  overflow: auto;
}

input {
  margin-right: 5px;
}

table {
  width: 100%;
}

td {
  border: solid 1px black;
}

React

class TodoApp extends React.Component {
  constructor(props) {
    super(props)
    this.state = {
    	items: Array.from({ length: 100 }, (v, k) => {
      	return { id: k, key: k, val: k };
      })
    }
  }
  
  componentDidMount(){
  const wrapper = document.getElementById("wrapper");
  wrapper.addEventListener("scroll", function(){
  	console.log(this)
     var translate = "translate(0,"+this.scrollTop+"px)";
     this.querySelector("thead").style.transform = translate;
  });
  }
  
  render() {
    return (
      <div id="wrapper">
        <table>
          <thead>
            <th>id</th>
            <th>key</th>
            <th>val</th>
          </thead>
          {this.state.items.map((item, i) => {
          	return (
            	<tr key={i}>
            	  <td>{item.id}</td>
                <td>{item.key}</td>
                <td>{item.val}</td>
            	</tr>
            );
          })}
        </table>
      </div>
    )
  }
}

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