Class QueryClient

Namespace

Velvet

Assembly

Velvet.Docs.dll

TanStack Query's QueryClient: a cache of query results keyed by QueryKey, shared by every UseQuery<TQueryFnData, TData>(QueryOptions<TQueryFnData, TData>, QueryClient?) that reaches it. One entry holds one result and at most one request in flight, whichever component started it, and keeps the result after the components reading it unmount, until it is collected. A request in flight is kept too when its query function takes no token; one that does is cancelled when the last component reading the entry leaves, as QueryFn describes.

public sealed class QueryClient

Inheritance

object

QueryClient

Remarks

Main thread only, like the rest of Velvet. An entry nothing observes is removed once its garbage-collection time has passed on the client's clock, as TanStack Query's timer removes it. The clock is read once a frame, as a retry's wait is, while an entry that can still expire is held: removal lands on the first frame whose reading is at or past the deadline, and an entry whose time has run out reads as absent before then. The loop holds the client weakly, so it is not what keeps a dropped client alive. An entry with a request in flight has not run out, as v5 puts its removal off while it fetches: it runs out a whole garbage-collection time after the request settles, and the clock is read every frame until then.

Constructors

QueryClient(QueryClientOptions?)

Creates an empty client.

Properties

DefaultGcTime

The garbage-collection time a query that sets none of its own uses.

DefaultRefetchOnReconnect

Whether a query that sets none of its own fetches again when the device comes back online.

DefaultRefetchOnReconnectFn

The function a query that sets none of its own decides whether to fetch again when the device comes back online with; it replaces DefaultRefetchOnReconnect.

DefaultRefetchOnWindowFocus

Whether a query that sets none of its own fetches again when the application becomes visible.

DefaultRefetchOnWindowFocusFn

The function a query that sets none of its own decides whether to fetch again when the application becomes visible with; it replaces DefaultRefetchOnWindowFocus.

DefaultRetry

The number of retries a query that sets none of its own uses.

DefaultRetryDelay

The retry delay a query that sets none of its own uses.

DefaultStaleTime

The stale time a query that sets none of its own uses.

Methods

CancelQueries(QueryFilters?, bool)

Cancels the requests of the entries filters selects, TanStack Query's cancelQueries. The token a cancelled query function received is cancelled, and a task a caller awaits for the request, such as FetchQuery<T>(QueryOptions<T, T>)'s, is cancelled with it.

Clear()

Removes every entry and cancels every request in flight, as TanStack Query's clear(). A mounted query re-renders without data and fetches into a new entry.

EnsureQueryData<T>(QueryOptions<T, T>, bool)

The data the entry options names holds, and otherwise the data a request for it returns, TanStack Query's ensureQueryData.

FetchQuery<T>(QueryOptions<T, T>)

The data options' entry holds when it is fresh for the query's stale time, and otherwise the data a request for it returns, TanStack Query's fetchQuery. A request in flight is joined. The entry is created when there is none and, with nothing reading it, collected after the query's garbage-collection time.

GetQueriesData<T>(QueryFilters?)

The key and data of each entry filters selects that holds data of type T, TanStack Query's getQueriesData. An entry holding another type is left out rather than throwing, since a filter selects across keys.

GetQueryData<T>(QueryKey)

The data the entry queryKey names holds, TanStack Query's getQueryData: default when there is no such entry, it has no data yet, or it has gone unread past its garbage-collection time. Placeholder data is never an entry's.

GetQueryState<T>(QueryKey)

The state of the entry queryKey names, TanStack Query's getQueryState: null when there is no such entry or it has gone unread past its garbage-collection time.

InvalidateQueries(QueryFilters?, RefetchOptions?)

InvalidateQueries(QueryKey?) over the entries filters selects, TanStack Query's invalidateQueries(filters, options). Only entries an enabled query reads are fetched again.

InvalidateQueries(QueryKey?)

Marks every entry whose key queryKey matches stale, and fetches again each one a mounted query is reading — TanStack Query's invalidateQueries({ queryKey }), with the partial match of its filter that QueryKey describes. For such an entry, a request already in flight is cancelled and started over when the entry holds data, so a result fetched before the change that invalidated it does not land as current, and joined when the entry is still waiting on its first result. An entry nothing reads is not fetched: a query mounting over it later fetches it, and a request it still has in flight, one whose query function takes no token, is left to land.

PrefetchQuery<T>(QueryOptions<T, T>)

FetchQuery<T>(QueryOptions<T, T>) without the data: fills the cache ahead of the component that reads it. TanStack Query's prefetchQuery.

RefetchQueries(QueryFilters?, RefetchOptions?)

Fetches again the entries filters selects that can be: those an enabled query reads, and, for an entry nothing reads, those that were fetched before and keep the options of that fetch. TanStack Query's refetchQueries.

RemoveQueries(QueryFilters?)

Removes the entries filters selects and cancels their requests, TanStack Query's removeQueries. A mounted query reading a removed entry re-renders without data and fetches into a new one, as after Clear().

ResetQueries(QueryFilters?, RefetchOptions?)

Puts the entries filters selects back to the state of one never fetched, with no data and no error, cancelling their requests, and then fetches those an enabled query reads — TanStack Query's resetQueries. A Type of null refetches the active entries; one that is set also selects what is refetched.

SetQueriesData<T>(QueryFilters?, Func<T?, T>)

SetQueryData<T>(QueryKey, Func<T?, T>) over each entry filters selects that holds data of type T, TanStack Query's setQueriesData. An updater returning null leaves its entry as it was.

SetQueryData<T>(QueryKey, Func<T?, T>)

SetQueryData<T>(QueryKey, T) with the data updater makes of the data the entry holds, default when it holds none, as TanStack Query's functional updater. An updater returning null writes nothing.

SetQueryData<T>(QueryKey, T)

Writes data into the entry queryKey names, creating it when there is none, TanStack Query's setQueryData: the entry becomes Success with fresh data and no error, and the queries reading it are told, re-rendering for what changed. The data is shared structurally with what the entry held, as a request landing is. A request in flight is left running and lands over it. A new entry nothing reads expires after DefaultGcTime. A null data writes nothing.