我正在使用Infinite scroll component 。它正在工作,但多次请求同一端点(3 -4 次)。根据我的 React 知识,让我解释一下发生了什么:
因为我设置了initialLoad={true},所以loadMore函数将在组件渲染后立即调用。我可以设置 initialLoad={false} 但它不会在初始渲染中获取数据
- 在第一次渲染中,它调用 loadMore 函数 ==> 正在加载 状态已更改 ==> 第二次渲染
- 在第二次渲染中,它调用 loadMore 函数 ==> tracks 状态已更改 ==> 第三次渲染
- 在第三次渲染中,它调用loadMore函数==>某些状态发生了变化==>第四次渲染
Index.js
export default function index() {
const { tracks, error, loading, loadMore, hasMore } = usePublicTracks(
myApiEndPoint.TRENDING_TRACKS,
5,
);
return (
<div>
<Main>
<InfiniteScroll
initialLoad={true} //call loadMore function right after component rendered
pageStart={0}
loadMore={loadMore}
hasMore={hasMore}
>
<TrackList>
{tracks.map((track, i) => (
<TrackItem key={i}
track={track}
/>
))}
</TrackList>
{loading && hasMore && (
<div className="">
<Spin />
</div>
)}
</InfiniteScroll>
</Main>
</div>
);
}
usePublicTracks.js
export const usePublicTracks = (endpoint, limit) => {
const [loading, setLoading] = useState(true);
const [error, setError] = useState(null);
const [offset, setOffset] = useState('');
const [tracks, setTracks] = useState([])
const [hasMore, setHasMore] = useState(true);
console.log('tracks', tracks)
const loadMore = async params => {
try {
console.log('hello22222222222222222222222222222222222222222')
const res = await myApiAxiosInstance.get(endpoint, {
params: {
limit: limit,
lastVisible: offset
}
});
setLoading(false);
setTracks([...tracks, ...(res.data.collection)])
setOffset(res.data.lastVisible)
if (res.data.lastVisible == "end") setHasMore(false);
} catch (error) {
setLoading(false);
setError(error.message);
}
};
return {
error,
loading,
tracks,
loadMore,
hasMore
};
};
当我将 loadMore 函数包装在 useEffect 中时,它显示错误 Hooks can only be called inside of a function component.:
const loadMore = async params => {
useEffect(() => {
const loadMoreOnce = async () => {
//some logic
};
loadMoreOnce();
}, []);
};
我的问题是如何调用一次加载更多函数。然后每次滚动到窗口底部时调用它?如何防止多次请求同一端点?
最佳答案
const isLoading = false;
const myComponent = () => {
useEffect(() => {
loadMore(); // initial call, this useEffect equivalent to componentDidMount
}, []);
if (!isLoading && document.body.scrollTop >= document.body.offsetTop) {
console.log('loading, should see this once');
isLoading = true;
loadMore(); // here, after loadMore finished you need to resolve isLoading to false
}
return (<div>My component</div>);
}
尝试找到所有对loadMore函数的调用,也许在其他地方也调用了它,改变从页面开始的偏移量,检查hasMore条件是否正确,因为多个调用也可以来自InfiniteScroll本身,当它认为您多次触底。
关于javascript - react : App requests same endpoint multiple times,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/59118956/