QueriesObserver

Defined in: packages/query-core/src/queriesObserver.ts:56

A QueriesObserver watches an array of queries at once, exposing them as a single array of QueryObserverResults (or, when a combine option is given, as a combined value derived from that array). It manages one internal QueryObserver per query, and is the primitive that framework adapters (e.g. useQueries) build their hooks on top of.

Example#

const observer = new QueriesObserver(queryClient, [
  { queryKey: ['post', 1], queryFn: fetchPost },
  { queryKey: ['post', 2], queryFn: fetchPost },
])

const unsubscribe = observer.subscribe((result) => {
  console.log(result)
})

Extends#

• Subscribable<QueriesObserverListener>

Type Parameters#

TCombinedResult#

TCombinedResult = QueryObserverResult[]

Constructors#

Constructor#

new QueriesObserver<TCombinedResult>(
   client, 
   queries, 
options?): QueriesObserver<TCombinedResult>;

Defined in: packages/query-core/src/queriesObserver.ts:70

Parameters#

client#

QueryClient

queries#

QueryObserverOptions<any, any, any, any, any, never>[]

options?#

QueriesObserverOptions<TCombinedResult>

Returns#

QueriesObserver<TCombinedResult>

Overrides#

Subscribable<QueriesObserverListener>.constructor

Properties#

listeners#

protected listeners: Set<QueriesObserverListener>;

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

Inherited from#

Subscribable.listeners

Methods#

destroy()#

destroy(): void;

Defined in: packages/query-core/src/queriesObserver.ts:106

Stops observing all queries: clears all listeners and destroys every underlying QueryObserver this observer manages.

Returns#

void

getCurrentResult()#

getCurrentResult(): QueryObserverResult[];

Defined in: packages/query-core/src/queriesObserver.ts:210

Returns the most recently computed array of QueryObserverResults, one per observed query, in the same order as the queries passed to the constructor or setQueries.

Returns#

QueryObserverResult[]

Example#

const results = observer.getCurrentResult()
const data = results.map((result) => result.data)

getObservers()#

getObservers(): QueryObserver<unknown, Error, unknown, unknown, readonly unknown[]>[];

Defined in: packages/query-core/src/queriesObserver.ts:227

Returns the underlying QueryObserver instances this observer manages, in the same order as the queries passed to the constructor or setQueries.

Returns#

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

getOptimisticResult()#

getOptimisticResult(queries, combine): [QueryObserverResult[], (r?) => TCombinedResult, () => QueryObserverResult[]];

Defined in: packages/query-core/src/queriesObserver.ts:238

The QueriesObserver counterpart of QueryObserver#getOptimisticResult — computes the result for the given (already-defaulted) queries right now, synchronously. Called by framework adapters (e.g. useQueries) ahead of subscribing, returning a tuple of the raw per-query results, a function to compute the combined result from them, and a function to wrap the results for property-access tracking.

Parameters#

queries#

QueryObserverOptions<unknown, Error, unknown, unknown, readonly unknown[], never>[]

combine#

CombineFn<TCombinedResult> | undefined

Returns#

[QueryObserverResult[], (r?) => TCombinedResult, () => QueryObserverResult[]]

getQueries()#

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

Defined in: packages/query-core/src/queriesObserver.ts:218

Returns the underlying Query instances currently being observed, in the same order as the queries passed to the constructor or setQueries.

Returns#

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

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/queriesObserver.ts:86

Returns#

void

Overrides#

Subscribable.onSubscribe

onUnsubscribe()#

protected onUnsubscribe(): void;

Defined in: packages/query-core/src/queriesObserver.ts:96

Returns#

void

Overrides#

Subscribable.onUnsubscribe

setQueries()#

setQueries(queries, options?): void;

Defined in: packages/query-core/src/queriesObserver.ts:127

Replaces the set of queries being observed. Existing QueryObservers are reused for queries that match an already-observed query hash; observers for queries that are no longer present are destroyed, and new observers are created and subscribed to for newly added queries.

Parameters#

queries#

QueryObserverOptions<unknown, Error, unknown, unknown, readonly unknown[], never>[]

options?#

QueriesObserverOptions<TCombinedResult>

Returns#

void

Example#

observer.setQueries([
  { queryKey: ['post', 1], queryFn: fetchPost },
  { queryKey: ['post', 3], queryFn: fetchPost },
])

subscribe()#

subscribe(listener): () => void;

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

Parameters#

listener#

QueriesObserverListener

Returns#

(): void;

Returns#

void

Inherited from#

Subscribable.subscribe