React
by Abdul Ahmad
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
function TodoApp() {
const incrementFetchDataCounter = useDataFetcher();
return (
<div>
<button onClick={incrementFetchDataCounter}>
fetch data again
</button>
</div>
);
}
function useDataFetcher() {
const [fetchDataCounter, setFetchDataCounter] = React.useState(0);
React.useEffect(() => {
console.log('using effect');
async function fetchData() {
console.log('fetching data');
const data = await fetchDataAsync();
}
fetchData();
}, [fetchDataCounter]);
return () => setFetchDataCounter(fetchDataCounter + 1);
}
function fetchDataAsync() {
return Promise.resolve('data');
}
ReactDOM.render(<TodoApp />, document.querySelector("#app"))