Add possibility to pass a callback to enabled.

docs/framework/react/guides/disabling-queries.md

@@ -3,7 +3,7 @@ id: disabling-queries
 title: Disabling/Pausing Queries
 ---
 
-If you ever want to disable a query from automatically running, you can use the `enabled = false` option.
+If you ever want to disable a query from automatically running, you can use the `enabled = false` option. The enabled option also accepts a callback that returns a boolean.
 
 When `enabled` is `false`:
 

docs/framework/react/react-native.md

@@ -143,3 +143,34 @@ function MyComponent() {
   return <Text>DataUpdatedAt: {dataUpdatedAt}</Text>
 }
 ```
+
+## Disable queries on out of focus screens
+
+Enabled can also be set to a callback to support disabling queries on out of focus screens without state and re-rendering on navigation, similar to how notifyOnChangeProps works but in addition it wont trigger refetching when invalidating queries with refetchType active.
+
+```tsx
+import React from 'react'
+import { useFocusEffect } from '@react-navigation/native'
+
+export function useQueryFocusAware(notifyOnChangeProps?: NotifyOnChangeProps) {
+  const focusedRef = React.useRef(true)
+
+  useFocusEffect(
+    React.useCallback(() => {
+      focusedRef.current = true
+
+      return () => {
+        focusedRef.current = false
+      }
+    }, []),
+  )
+
+  return () => focusRef.current
+
+  useQuery({
+    queryKey: ['key'],
+    queryFn: () => fetch(...),
+    enabled: () => focusedRef.current,
+  })
+}
+```

packages/query-core/src/__tests__/queryObserver.test.tsx

@@ -52,6 +52,173 @@ describe('queryObserver', () => {
     unsubscribe()
   })
 
+  describe('enabled is a callback that initially returns false and', () => {
+    let observer: QueryObserver<string, Error, string, string, string[]>
+    let enabled: boolean
+    let count: number
+    let key: string[]
+
+    beforeEach(() => {
+      key = queryKey()
+      count = 0
+      enabled = false
+
+      observer = new QueryObserver(queryClient, {
+        queryKey: key,
+        staleTime: Infinity,
+        enabled: () => enabled,
+        queryFn: async () => {
+          await sleep(10)
+          count++
+          return 'data'
+        },
+      })
+    })
+
+    test('should not fetch on mount', () => {
+      let unsubscribe = observer.subscribe(vi.fn())
+
+      // Has not fetched and is not fetching since its disabled
+      expect(count).toBe(0)
+      expect(observer.getCurrentResult()).toMatchObject({
+        status: 'pending',
+        fetchStatus: 'idle',
+        data: undefined,
+      })
+
+      unsubscribe()
+    })
+
+    test('should not be refetched when invalidated with refetchType: all', async () => {
+      let unsubscribe = observer.subscribe(vi.fn())
+
+      queryClient.invalidateQueries({ queryKey: key, refetchType: 'all' })
+
+      //So we still expect it to not have fetched and not be fetching
+      expect(count).toBe(0)
+      expect(observer.getCurrentResult()).toMatchObject({
+        status: 'pending',
+        fetchStatus: 'idle',
+        data: undefined,
+      })
+      await waitFor(() => expect(count).toBe(0))
+
+      unsubscribe()
+    })
+
+    test('should still trigger a fetch when refetch is called', async () => {
+      let unsubscribe = observer.subscribe(vi.fn())
+
+      expect(enabled).toBe(false)
+
+      //Not the same with explicit refetch, this will override enabled and trigger a fetch anyway
+      observer.refetch()
+
+      expect(observer.getCurrentResult()).toMatchObject({
+        status: 'pending',
+        fetchStatus: 'fetching',
+        data: undefined,
+      })
+
+      await waitFor(() => expect(count).toBe(1))
+      expect(observer.getCurrentResult()).toMatchObject({
+        status: 'success',
+        fetchStatus: 'idle',
+        data: 'data',
+      })
+
+      unsubscribe()
+    })
+
+    test('should fetch if unsubcribed, then enabled returns true, and then re-suscribed', async () => {
+      let unsubscribe = observer.subscribe(vi.fn())
+      expect(observer.getCurrentResult()).toMatchObject({
+        status: 'pending',
+        fetchStatus: 'idle',
+        data: undefined,
+      })
+
+      unsubscribe()
+
+      enabled = true
+
+      unsubscribe = observer.subscribe(vi.fn())
+
+      expect(observer.getCurrentResult()).toMatchObject({
+        status: 'pending',
+        fetchStatus: 'fetching',
+        data: undefined,
+      })
+
+      await waitFor(() => expect(count).toBe(1))
+
+      unsubscribe()
+    })
+
+    test('should not be refetched if not subscribed to after enabled was toggled to true', async () => {
+      let unsubscribe = observer.subscribe(vi.fn())
+
+      // Toggle enabled
+      enabled = true
+
+      unsubscribe()
+
+      queryClient.invalidateQueries({ queryKey: key, refetchType: 'active' })
+
+      expect(observer.getCurrentResult()).toMatchObject({
+        status: 'pending',
+        fetchStatus: 'idle',
+        data: undefined,
+      })
+      expect(count).toBe(0)
+    })
+
+    test('should not be refetched if not subscribed to after enabled was toggled to true', async () => {
+      let unsubscribe = observer.subscribe(vi.fn())
+
+      // Toggle enabled
+      enabled = true
+
+      queryClient.invalidateQueries({ queryKey: key, refetchType: 'active' })
+
+      expect(observer.getCurrentResult()).toMatchObject({
+        status: 'pending',
+        fetchStatus: 'fetching',
+        data: undefined,
+      })
+      await waitFor(() => expect(count).toBe(1))
+
+      unsubscribe()
+    })
+
+    test('should handle that the enabled callback updates the return value', async () => {
+      let unsubscribe = observer.subscribe(vi.fn())
+
+      // Toggle enabled
+      enabled = true
+
+      queryClient.invalidateQueries({ queryKey: key, refetchType: 'inactive' })
+
+      //should not refetch since it was active and we only refetch inactive
+      await waitFor(() => expect(count).toBe(0))
+
+      queryClient.invalidateQueries({ queryKey: key, refetchType: 'active' })
+
+      //should refetch since it was active and we refetch active
+      await waitFor(() => expect(count).toBe(1))
+
+      // Toggle enabled
+      enabled = false
+
+      //should not refetch since it is not active and we only refetch active
+      queryClient.invalidateQueries({ queryKey: key, refetchType: 'active' })
+
+      await waitFor(() => expect(count).toBe(1))
+
+      unsubscribe()
+    })
+  })
+
   test('should be able to read latest data when re-subscribing (but not re-fetching)', async () => {
     const key = queryKey()
     let count = 0
@@ -429,6 +596,34 @@ describe('queryObserver', () => {
     expect(queryFn).toHaveBeenCalledTimes(0)
   })
 
+  test('should not trigger a fetch when subscribed and disabled by callback', async () => {
+    const key = queryKey()
+    const queryFn = vi.fn<Array<unknown>, string>().mockReturnValue('data')
+    const observer = new QueryObserver(queryClient, {
+      queryKey: key,
+      queryFn,
+      enabled: () => false,
+    })
+    const unsubscribe = observer.subscribe(() => undefined)
+    await sleep(1)
+    unsubscribe()
+    expect(queryFn).toHaveBeenCalledTimes(0)
+  })
+
+  test('should not trigger a fetch when subscribed and disabled by callback', async () => {
+    const key = queryKey()
+    const queryFn = vi.fn<Array<unknown>, string>().mockReturnValue('data')
+    const observer = new QueryObserver(queryClient, {
+      queryKey: key,
+      queryFn,
+      enabled: () => false,
+    })
+    const unsubscribe = observer.subscribe(() => undefined)
+    await sleep(1)
+    unsubscribe()
+    expect(queryFn).toHaveBeenCalledTimes(0)
+  })
+
   test('should not trigger a fetch when not subscribed', async () => {
     const key = queryKey()
     const queryFn = vi.fn<Array<unknown>, string>().mockReturnValue('data')

packages/query-core/src/query.ts

@@ -1,4 +1,10 @@
-import { ensureQueryFn, noop, replaceData, timeUntilStale } from './utils'
+import {
+  ensureQueryFn,
+  noop,
+  replaceData,
+  resolveEnabled,
+  timeUntilStale,
+} from './utils'
 import { notifyManager } from './notifyManager'
 import { canFetch, createRetryer, isCancelledError } from './retryer'
 import { Removable } from './removable'
@@ -244,7 +250,9 @@ export class Query<
   }
 
   isActive(): boolean {
-    return this.observers.some((observer) => observer.options.enabled !== false)
+    return this.observers.some(
+      (observer) => resolveEnabled(observer.options.enabled, this) !== false,
+    )
   }
 
   isDisabled(): boolean {

packages/query-core/src/queryObserver.ts

@@ -3,6 +3,7 @@ import {
   isValidTimeout,
   noop,
   replaceData,
+  resolveEnabled,
   resolveStaleTime,
   shallowEqualObjects,
   timeUntilStale,
@@ -149,9 +150,14 @@ export class QueryObserver<
 
     if (
       this.options.enabled !== undefined &&
-      typeof this.options.enabled !== 'boolean'
+      typeof this.options.enabled !== 'boolean' &&
+      typeof this.options.enabled !== 'function' &&
+      typeof resolveEnabled(this.options.enabled, this.#currentQuery) !==
+        'boolean'
     ) {
-      throw new Error('Expected enabled to be a boolean')
+      throw new Error(
+        'Expected enabled to be a boolean or a callback that returns a boolean',
+      )
     }
 
     this.#updateQuery()
@@ -190,7 +196,8 @@ export class QueryObserver<
     if (
       mounted &&
       (this.#currentQuery !== prevQuery ||
-        this.options.enabled !== prevOptions.enabled ||
+        resolveEnabled(this.options.enabled, this.#currentQuery) !==
+          resolveEnabled(prevOptions.enabled, this.#currentQuery) ||
         resolveStaleTime(this.options.staleTime, this.#currentQuery) !==
           resolveStaleTime(prevOptions.staleTime, this.#currentQuery))
     ) {
@@ -203,7 +210,8 @@ export class QueryObserver<
     if (
       mounted &&
       (this.#currentQuery !== prevQuery ||
-        this.options.enabled !== prevOptions.enabled ||
+        resolveEnabled(this.options.enabled, this.#currentQuery) !==
+          resolveEnabled(prevOptions.enabled, this.#currentQuery) ||
         nextRefetchInterval !== this.#currentRefetchInterval)
     ) {
       this.#updateRefetchInterval(nextRefetchInterval)
@@ -377,7 +385,7 @@ export class QueryObserver<
 
     if (
       isServer ||
-      this.options.enabled === false ||
+      resolveEnabled(this.options.enabled, this.#currentQuery) === false ||
       !isValidTimeout(this.#currentRefetchInterval) ||
       this.#currentRefetchInterval === 0
     ) {
@@ -692,7 +700,7 @@ function shouldLoadOnMount(
   options: QueryObserverOptions<any, any, any, any>,
 ): boolean {
   return (
-    options.enabled !== false &&
+    resolveEnabled(options.enabled, query) !== false &&
     query.state.data === undefined &&
     !(query.state.status === 'error' && options.retryOnMount === false)
   )
@@ -716,7 +724,7 @@ function shouldFetchOn(
     (typeof options)['refetchOnWindowFocus'] &
     (typeof options)['refetchOnReconnect'],
 ) {
-  if (options.enabled !== false) {
+  if (resolveEnabled(options.enabled, query) !== false) {
     const value = typeof field === 'function' ? field(query) : field
 
     return value === 'always' || (value !== false && isStale(query, options))
@@ -731,7 +739,8 @@ function shouldFetchOptionally(
   prevOptions: QueryObserverOptions<any, any, any, any, any>,
 ): boolean {
   return (
-    (query !== prevQuery || prevOptions.enabled === false) &&
+    (query !== prevQuery ||
+      resolveEnabled(prevOptions.enabled, query) === false) &&
     (!options.suspense || query.state.status !== 'error') &&
     isStale(query, options)
   )
@@ -742,7 +751,7 @@ function isStale(
   options: QueryObserverOptions<any, any, any, any, any>,
 ): boolean {
   return (
-    options.enabled !== false &&
+    resolveEnabled(options.enabled, query) !== false &&
     query.isStaleByTime(resolveStaleTime(options.staleTime, query))
   )
 }

packages/query-core/src/types.ts

@@ -54,6 +54,15 @@ export type StaleTime<
   TQueryKey extends QueryKey = QueryKey,
 > = number | ((query: Query<TQueryFnData, TError, TData, TQueryKey>) => number)
 
+export type Enabled<
+  TQueryFnData = unknown,
+  TError = DefaultError,
+  TData = TQueryFnData,
+  TQueryKey extends QueryKey = QueryKey,
+> =
+  | boolean
+  | ((query: Query<TQueryFnData, TError, TData, TQueryKey>) => boolean)
+
 export type QueryPersister<
   T = unknown,
   TQueryKey extends QueryKey = QueryKey,
@@ -255,9 +264,10 @@ export interface QueryObserverOptions<
   /**
    * Set this to `false` to disable automatic refetching when the query mounts or changes query keys.
    * To refetch the query, use the `refetch` method returned from the `useQuery` instance.
+   * You can also pass a callback that returns a boolean to check this condition dynamically.
    * Defaults to `true`.
    */
-  enabled?: boolean
+  enabled?: Enabled<TQueryFnData, TError, TQueryData, TQueryKey>
   /**
    * The time in milliseconds after data is considered stale.
    * If set to `Infinity`, the data will never be considered stale.