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id QueryCache
title QueryCache

Defined in: packages/query-core/src/queryCache.ts:123

The QueryCache is the storage mechanism for TanStack Query. It stores all the data, meta information, and state of the queries it contains.

Normally, you will not interact with the QueryCache directly and instead use a QueryClient for a specific cache. You can subscribe to it (inherited from Subscribable) to be informed of safe/known updates to the cache, such as queries being added, removed, or updated — updates made outside of the cache's own tracked mechanisms (e.g. mutating a query's state object directly) do not notify subscribers.

Example

const unsubscribe = queryCache.subscribe((event) => {
  console.log(event.type, event.query)
})

Extends

  • Subscribable<QueryCacheListener>

Constructors

Constructor

new QueryCache(config: QueryCacheConfig): QueryCache;

Defined in: packages/query-core/src/queryCache.ts:126

Parameters

config

QueryCacheConfig = {}

Returns

QueryCache

Overrides

Subscribable<QueryCacheListener>.constructor

Properties

config

config: QueryCacheConfig = {};

Defined in: packages/query-core/src/queryCache.ts:126

listeners

protected listeners: Set<QueryCacheListener>;

Defined in: packages/query-core/src/subscribable.ts:2

Inherited from

Subscribable.listeners

Methods

build()

build<TQueryFnData, TError, TData, TQueryKey>(
   client: QueryClient, 
   options: WithRequired<QueryOptions<TQueryFnData, TError, TData, TQueryKey, never>, "queryKey">, 
state?: QueryState<TData, TError>): Query<TQueryFnData, TError, TData, TQueryKey>;

Defined in: packages/query-core/src/queryCache.ts:147

Returns the existing Query instance for the given options' queryKey/queryHash, or builds and adds a new one to the cache if none exists yet. Used by framework adapters and plugins (e.g. broadcast/persistence) that need to get-or-create a Query directly, bypassing the reactive QueryObserver machinery.

Type Parameters

TQueryFnData

TQueryFnData = unknown

TError

TError = Error

TData

TData = TQueryFnData

TQueryKey

TQueryKey extends readonly unknown[] = readonly unknown[]

Parameters

client

QueryClient

options

WithRequired<QueryOptions<TQueryFnData, TError, TData, TQueryKey, never>, "queryKey">

state?

QueryState<TData, TError>

Returns

Query<TQueryFnData, TError, TData, TQueryKey>

Example

const queryCache = queryClient.getQueryCache()

const query = queryCache.build(queryClient, {
  queryKey: ['posts'],
  queryFn: fetchPosts,
})

clear()

clear(): void;

Defined in: packages/query-core/src/queryCache.ts:228

Removes all queries from the cache.

Returns

void

Example

const queryCache = queryClient.getQueryCache()

queryCache.clear()

find()

find<TQueryFnData, TError, TData>(filters: WithRequired<QueryFilters<readonly unknown[]>, "queryKey">): 
  | Query<TQueryFnData, TError, TData, readonly unknown[]>
  | undefined;

Defined in: packages/query-core/src/queryCache.ts:295

A slightly more advanced method that can be used to get an existing query instance from the cache. This instance not only contains all the state for the query, but all of the instances, and underlying guts of the query as well. If the query does not exist, undefined is returned.

This is not typically needed for most applications, but can come in handy when needing more information about a query in rare scenarios (e.g. looking at query.state.dataUpdatedAt to decide whether a query is fresh enough to be used as an initial value).

Type Parameters

TQueryFnData

TQueryFnData = unknown

TError

TError = Error

TData

TData = TQueryFnData

Parameters

filters

WithRequired<QueryFilters<readonly unknown[]>, "queryKey">

Returns

| Query<TQueryFnData, TError, TData, readonly unknown[]> | undefined

See

QueryCache#findAll

Example

const queryCache = queryClient.getQueryCache()

const query = queryCache.find({ queryKey: ['posts'] })

findAll()

findAll(filters: QueryFilters<any>): Query<unknown, Error, unknown, readonly unknown[]>[];

Defined in: packages/query-core/src/queryCache.ts:320

An even more advanced method that can be used to get existing query instances from the cache that partially match a query key. If no queries match, an empty array is returned.

This is not typically needed for most applications, but can come in handy when needing more information about queries in rare scenarios.

Parameters

filters

QueryFilters<any> = {}

Returns

Query<unknown, Error, unknown, readonly unknown[]>[]

See

QueryCache#find

Example

const queryCache = queryClient.getQueryCache()

const queries = queryCache.findAll({ queryKey: ['posts'] })

get()

get<TQueryFnData, TError, TData, TQueryKey>(queryHash: string): 
  | Query<TQueryFnData, TError, TData, TQueryKey>
  | undefined;

Defined in: packages/query-core/src/queryCache.ts:250

Returns the Query instance stored under the given queryHash, or undefined if none exists. Unlike QueryCache#find, this looks up by the already-computed hash rather than by QueryFilters. Used by plugins (e.g. broadcast/hydration) that already have a hash to look up directly.

Type Parameters

TQueryFnData

TQueryFnData = unknown

TError

TError = Error

TData

TData = TQueryFnData

TQueryKey

TQueryKey extends readonly unknown[] = readonly unknown[]

Parameters

queryHash

string

Returns

| Query<TQueryFnData, TError, TData, TQueryKey> | undefined

Example

const queryCache = queryClient.getQueryCache()
const queryHash = hashKey(['posts'])

const query = queryCache.get(queryHash)

getAll()

getAll(): Query<unknown, Error, unknown, readonly unknown[]>[];

Defined in: packages/query-core/src/queryCache.ts:273

Returns all queries within the cache.

Returns

Query<unknown, Error, unknown, readonly unknown[]>[]

Example

const queryCache = queryClient.getQueryCache()

const queries = queryCache.getAll()

hasListeners()

hasListeners(): boolean;

Defined in: packages/query-core/src/subscribable.ts:19

Returns

boolean

Inherited from

Subscribable.hasListeners

onSubscribe()

protected onSubscribe(): void;

Defined in: packages/query-core/src/subscribable.ts:23

Returns

void

Inherited from

Subscribable.onSubscribe

onUnsubscribe()

protected onUnsubscribe(): void;

Defined in: packages/query-core/src/subscribable.ts:27

Returns

void

Inherited from

Subscribable.onUnsubscribe

remove()

remove(query: Query<any, any, any, any>): void;

Defined in: packages/query-core/src/queryCache.ts:208

Destroys the given Query and removes it from the cache, notifying subscribers with a 'removed' event. A no-op if the query is no longer the one currently stored under its hash (e.g. it was already replaced). Used by plugins (e.g. the broadcast client) that mirror removals across QueryCache instances.

Parameters

query

Query<any, any, any, any>

Returns

void

Example

const queryCache = queryClient.getQueryCache()
const query = queryCache.find({ queryKey: ['posts'] })

if (query) {
  queryCache.remove(query)
}

subscribe()

subscribe(listener: QueryCacheListener): () => void;

Defined in: packages/query-core/src/subscribable.ts:8

Parameters

listener

QueryCacheListener

Returns

(): void;
Returns

void

Inherited from

Subscribable.subscribe