如何在从外部 api 获取数据时使用引导加载微调器？

Question

While fetching information from a url takes a long time, how can I utilize the bootstrap load spinner to hide the delay and make the website looks more interactive?

Answer 1

I prefer to have a single state that stores all the information about the request ie it's status , data & error .

Based on the status field you have render the appropriate UI (like loading spinner, error screen).

I have used the state hook in the example below, you can also use the reducer hook if you prefer.

 function App(props) { const [{ status, data, error }, setState] = React.useState({ status: "PENDING", data: null, error: null }); React.useEffect(() => { let isCancelled = false; setState({ status: "PENDING", data: null, error: null }); fetch("https://jsonplaceholder.typicode.com/todos/1").then(res => res.json()).then(data => { if (isCancelled) { return; } setState({ status: "RESOLVED", data, error: null }); }).catch((error) => setState({ status: "REJECTED", error, data: null })); return () => { isCancelled = true; }; }, []); if (status === "PENDING") { return <p>Loading...</p>; } else if (status === "REJECTED") { return <pre>{JSON.stringify(error)}</pre>; } else { return <pre>{JSON.stringify(data)}</pre>; } } const root = ReactDOM.createRoot(document.getElementById("root")); root.render( <React.StrictMode> <App /> </React.StrictMode> );

 <script crossorigin src="https://unpkg.com/react@18/umd/react.development.js"></script> <script crossorigin src="https://unpkg.com/react-dom@18/umd/react-dom.development.js"></script> <div id="root"></div>

Answer 2

const [loading, setLoading] = useState(false)
useEffect(() => {
setLoading(true)
// Do your Fetch and stuff
setLoading(false)

}, [])

There ya go