Validation retriggers when component is mounted again.

Bug report

Suppose I need to fetch data with a POST request, where I have to send the ids in the request body.

const MyComponent = (props) => {
    const body = useMemo( () => ({ ids: props.ids }), []) 
    const { data } = useSWR(['/api', body])

    return //...
}

This works fine, the problem is that when I go to another page and then get back to the first one (containing MyComponent) the request is retriggered. This makes sense since useMemo only caches the data as long as the component is mounted. But is there a way to avoid retriggering the request when mounting the component again?

Thanks in advance,

[Ashot-KR]

You can set revalidateOnMount as false in the hook options. But ideally you use SWR only for GET requests, because the idea of SWR is that it will revalidate in many cases to ensure data consistency

with revalidateOnMount: false swr doesn’t make request even when there is no cached data yet. with revalidateOnMount: true request will be send even if cached date exists. I think option revalidateOnCacheExists: false(or something like this) will be useful when we need to display cached date without any data requests.

[nikhilag]

What’s the reason for not fetching data if it doesn’t exist in cache when we set revalidateOnMount: false?