correct-apricot

How to get cache update in another component when data has been updated somewhere else?

Using tanstack/svelte-query. It returns undefined but the data in the cache is updated after fetching.

const queryClient = useQueryClient();
    $: cache = queryClient.getQueryState<Game[]>(['games'])

    $: console.log('cache', cache)

const queryClient = useQueryClient();
    $: cache = queryClient.getQueryState<Game[]>(['games'])

    $: console.log('cache', cache)

The code for fetch in the first component:

  const query = createQuery({
        queryKey: ['games'],
        queryFn: () => fetchGames(),
    })

  const query = createQuery({
        queryKey: ['games'],
        queryFn: () => fetchGames(),
    })

10 Replies

correct-apricotOP•2y ago

I don't know if the "getQueryState" will update the component if the cache is updating from somewhere else or not?

genetic-orange•2y ago

it does not because its not reactive. you basically always want to call useQuery again

correct-apricotOP•2y ago

Sorry I didn't get that completely. Could you please write a little more about this?

genetic-orange•2y ago

if you want to read data in another component, use the same useQuery hook with the games queryKey to read that data

genetic-orange•2y ago

https://tkdodo.eu/blog/react-query-as-a-state-manager

React Query as a State Manager

Everything you need to know to make React Query your single source of truth state manager for your async state

correct-apricotOP•2y ago

Thanks!

correct-apricotOP•2y ago

I was using this example: https://github.com/TanStack/query/blob/62704ce63a2c88c8005e037825060f33404cf74b/examples/svelte/basic/src/lib/Posts.svelte#L32

GitHub

query/examples/svelte/basic/src/lib/Posts.svelte at 62704ce63a2c88c...

🤖 Powerful asynchronous state management, server-state utilities and data fetching for the web. TS/JS, React Query, Solid Query, Svelte Query and Vue Query. - TanStack/query

genetic-orange•2y ago

it's a different usecase

correct-apricotOP•2y ago

Solved with what you wrote on your website. But then why do we have getQueryState and getQueryData?

getQueryState is a synchronous function that can be used to get an existing query's state. If the query does not exist, undefined will be returned.

getQueryState is a synchronous function that can be used to get an existing query's state. If the query does not exist, undefined will be returned.

getQueryData is a synchronous function that can be used to get an existing query's cached data. If the query does not exist, undefined will be returned.

getQueryData is a synchronous function that can be used to get an existing query's cached data. If the query does not exist, undefined will be returned.

As I was confused with the name for State in the getQueryState I thought it was reactive but turns out it was just the state of the data there 🙂 Thanks @TkDodo 🔮

genetic-orange•2y ago

for imperative function calls, like if you want to know the current state in an onClick handler. It's also what you need for optimistic updates

Gaming

Programming

How to get cache update in another component when data has been updated somewhere else?

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