React JS - 如何在状态更新之前阻止渲染 [Hooks]

Question

I have a component which fetch data from an API to display some details to user:

const ItemDetail = ({match}) => {
    const [item, setItem] = useState(null);

    useEffect(() => {
        const abort = new AbortController();
        fetchItem(abort);

        return function cleanUp(){
            abort.abort();
        }
    },[]);

    const fetchItem = async (abort) => {
        const data = await fetch(`https://fortnite-api.theapinetwork.com/item/get?id=${match.params.id}`, {
            signal: abort.signal
        });

        const fetchedItem = await data.json();
        setItem(fetchedItem.data.item);
    }

    return (
        <h1 className="title">{item.name}</h1>
    );
}

export default ItemDetail;

But when navigation reachs this component, the console shows the error Cannot access name of undefined , probably because the state was not updated yet.

Is it right to check item and return null if it was not updated yet? Something like this:

if(!item) return null;

return (
        <h1 className="title">{item.name}</h1>
);

Or in that case should be better to use a class extended by React.Component and deal with its lifecycle properly?

Answer 1

You handle this in one of two ways:

1. Have the component render itself in a "loading" state, or

2. Don't create the component until you have the data — eg, move the fetch operation into its parent, and only create the component once the parent has the data to render it (which you pass as props).