Query Options | TanStack Query Angular Docs

One of the best ways to share queryKey and queryFn between multiple places, yet keep them co-located to one another, is to use the queryOptions helper. At runtime, this helper just returns whatever you pass into it, but it has a lot of advantages when using it with TypeScript. You can define all possible options for a query in one place, and you'll also get type inference and type safety for all of them.

import { queryOptions, noop } from '@tanstack/angular-query-experimental'

@Injectable({
  providedIn: 'root',
})
export class QueriesService {
  private readonly http = inject(HttpClient)

  post(postId: number) {
    return queryOptions({
      queryKey: ['post', postId],
      queryFn: () => {
        return lastValueFrom(
          this.http.get<Post>(
            `https://jsonplaceholder.typicode.com/posts/${postId}`,
          ),
        )
      },
    })
  }
}

// usage:

postId = input.required({
  transform: numberAttribute,
})
queries = inject(QueriesService)

postQuery = injectQuery(() => this.queries.post(this.postId()))

queryClient.query(this.queries.post(23)).catch(noop)
queryClient.setQueryData(this.queries.post(42).queryKey, newPost)

For Infinite Queries, a separate infiniteQueryOptions helper is available.

You can still override some options at the component level. A very common and useful pattern is to create per-component select functions:

// Type inference still works, so groupQuery.data will be the return type of select instead of queryFn
queries = inject(QueriesService)

groupQuery = injectQuery(() => ({
  ...groupOptions(1),
  select: (data) => data.title,
}))