@tanstack/query-core/src/queryCache.ts

The framework agnostic core that powers TanStack Query

import { hashQueryKeyByOptions, matchQuery } from './utils'
import { Query } from './query'
import { notifyManager } from './notifyManager'
import { Subscribable } from './subscribable'
import type { QueryFilters } from './utils'
import type { Action, QueryState } from './query'
import type {
  DefaultError,
  NotifyEvent,
  QueryKey,
  QueryOptions,
  WithRequired,
} from './types'
import type { QueryClient } from './queryClient'
import type { QueryObserver } from './queryObserver'

// TYPES

interface QueryCacheConfig {
  onError?: (
    error: DefaultError,
    query: Query<unknown, unknown, unknown>,
  ) => void
  onSuccess?: (data: unknown, query: Query<unknown, unknown, unknown>) => void
  onSettled?: (
    data: unknown | undefined,
    error: DefaultError | null,
    query: Query<unknown, unknown, unknown>,
  ) => void
}

interface NotifyEventQueryAdded extends NotifyEvent {
  type: 'added'
  query: Query<any, any, any, any>
}

interface NotifyEventQueryRemoved extends NotifyEvent {
  type: 'removed'
  query: Query<any, any, any, any>
}

interface NotifyEventQueryUpdated extends NotifyEvent {
  type: 'updated'
  query: Query<any, any, any, any>
  action: Action<any, any>
}

interface NotifyEventQueryObserverAdded extends NotifyEvent {
  type: 'observerAdded'
  query: Query<any, any, any, any>
  observer: QueryObserver<any, any, any, any, any>
}

interface NotifyEventQueryObserverRemoved extends NotifyEvent {
  type: 'observerRemoved'
  query: Query<any, any, any, any>
  observer: QueryObserver<any, any, any, any, any>
}

interface NotifyEventQueryObserverResultsUpdated extends NotifyEvent {
  type: 'observerResultsUpdated'
  query: Query<any, any, any, any>
}

interface NotifyEventQueryObserverOptionsUpdated extends NotifyEvent {
  type: 'observerOptionsUpdated'
  query: Query<any, any, any, any>
  observer: QueryObserver<any, any, any, any, any>
}

export type QueryCacheNotifyEvent =
  | NotifyEventQueryAdded
  | NotifyEventQueryRemoved
  | NotifyEventQueryUpdated
  | NotifyEventQueryObserverAdded
  | NotifyEventQueryObserverRemoved
  | NotifyEventQueryObserverResultsUpdated
  | NotifyEventQueryObserverOptionsUpdated

type QueryCacheListener = (event: QueryCacheNotifyEvent) => void

export interface QueryStore {
  has: (queryHash: string) => boolean
  set: (queryHash: string, query: Query) => void
  get: (queryHash: string) => Query | undefined
  delete: (queryHash: string) => void
  values: () => IterableIterator<Query>
}

// CLASS

export class QueryCache extends Subscribable<QueryCacheListener> {
  #queries: QueryStore

  constructor(public config: QueryCacheConfig = {}) {
    super()
    this.#queries = new Map<string, Query>()
  }

  build<
    TQueryFnData = unknown,
    TError = DefaultError,
    TData = TQueryFnData,
    TQueryKey extends QueryKey = QueryKey,
  >(
    client: QueryClient,
    options: WithRequired<
      QueryOptions<TQueryFnData, TError, TData, TQueryKey>,
      'queryKey'
    >,
    state?: QueryState<TData, TError>,
  ): Query<TQueryFnData, TError, TData, TQueryKey> {
    const queryKey = options.queryKey
    const queryHash =
      options.queryHash ?? hashQueryKeyByOptions(queryKey, options)
    let query = this.get<TQueryFnData, TError, TData, TQueryKey>(queryHash)

    if (!query) {
      query = new Query({
        client,
        queryKey,
        queryHash,
        options: client.defaultQueryOptions(options),
        state,
        defaultOptions: client.getQueryDefaults(queryKey),
      })
      this.add(query)
    }

    return query
  }

  add(query: Query<any, any, any, any>): void {
    if (!this.#queries.has(query.queryHash)) {
      this.#queries.set(query.queryHash, query)

      this.notify({
        type: 'added',
        query,
      })
    }
  }

  remove(query: Query<any, any, any, any>): void {
    const queryInMap = this.#queries.get(query.queryHash)

    if (queryInMap) {
      query.destroy()

      if (queryInMap === query) {
        this.#queries.delete(query.queryHash)
      }

      this.notify({ type: 'removed', query })
    }
  }

  clear(): void {
    notifyManager.batch(() => {
      this.getAll().forEach((query) => {
        this.remove(query)
      })
    })
  }

  get<
    TQueryFnData = unknown,
    TError = DefaultError,
    TData = TQueryFnData,
    TQueryKey extends QueryKey = QueryKey,
  >(
    queryHash: string,
  ): Query<TQueryFnData, TError, TData, TQueryKey> | undefined {
    return this.#queries.get(queryHash) as
      | Query<TQueryFnData, TError, TData, TQueryKey>
      | undefined
  }

  getAll(): Array<Query> {
    return [...this.#queries.values()]
  }

  find<TQueryFnData = unknown, TError = DefaultError, TData = TQueryFnData>(
    filters: WithRequired<QueryFilters, 'queryKey'>,
  ): Query<TQueryFnData, TError, TData> | undefined {
    const defaultedFilters = { exact: true, ...filters }

    return this.getAll().find((query) =>
      matchQuery(defaultedFilters, query),
    ) as Query<TQueryFnData, TError, TData> | undefined
  }

  findAll(filters: QueryFilters<any> = {}): Array<Query> {
    const queries = this.getAll()
    return Object.keys(filters).length > 0
      ? queries.filter((query) => matchQuery(filters, query))
      : queries
  }

  notify(event: QueryCacheNotifyEvent): void {
    notifyManager.batch(() => {
      this.listeners.forEach((listener) => {
        listener(event)
      })
    })
  }

  onFocus(): void {
    notifyManager.batch(() => {
      this.getAll().forEach((query) => {
        query.onFocus()
      })
    })
  }

  onOnline(): void {
    notifyManager.batch(() => {
      this.getAll().forEach((query) => {
        query.onOnline()
      })
    })
  }
}