| --- |
| id: infinite-queries |
| title: Infinite Queries |
| ref: docs/framework/react/guides/infinite-queries.md |
| replace: |
| { 'useQuery': 'injectQuery', 'useInfiniteQuery': 'injectInfiniteQuery' } |
| --- |
| |
| [//]: # 'Example' |
|
|
| ```angular-ts |
| import { Component, computed, inject } from '@angular/core' |
| import { injectInfiniteQuery } from '@tanstack/angular-query-experimental' |
| import { lastValueFrom } from 'rxjs' |
| import { ProjectsService } from './projects-service' |
| |
| @Component({ |
| selector: 'example', |
| templateUrl: './example.component.html', |
| }) |
| export class Example { |
| projectsService = inject(ProjectsService) |
| |
| query = injectInfiniteQuery(() => ({ |
| queryKey: ['projects'], |
| queryFn: async ({ pageParam }) => { |
| return lastValueFrom(this.projectsService.getProjects(pageParam)) |
| }, |
| initialPageParam: 0, |
| getPreviousPageParam: (firstPage) => firstPage.previousId ?? undefined, |
| getNextPageParam: (lastPage) => lastPage.nextId ?? undefined, |
| maxPages: 3, |
| })) |
| |
| nextButtonDisabled = computed( |
| () => !this.#hasNextPage() || this.#isFetchingNextPage(), |
| ) |
| nextButtonText = computed(() => |
| this.#isFetchingNextPage() |
| ? 'Loading more...' |
| : this.#hasNextPage() |
| ? 'Load newer' |
| : 'Nothing more to load', |
| ) |
| |
| #hasNextPage = this.query.hasNextPage |
| #isFetchingNextPage = this.query.isFetchingNextPage |
| } |
| ``` |
|
|
| ```angular-html |
| <div> |
| @if (query.isPending()) { |
| <p>Loading...</p> |
| } @else if (query.isError()) { |
| <span>Error: {{ query?.error().message }}</span> |
| } @else { @for (page of query?.data().pages; track $index) { @for (project of |
| page.data; track project.id) { |
| <p>{{ project.name }} {{ project.id }}</p> |
| } } |
| <div> |
| <button (click)="query.fetchNextPage()" [disabled]="nextButtonDisabled()"> |
| {{ nextButtonText() }} |
| </button> |
| </div> |
| } |
| </div> |
| ``` |
|
|
| [//]: # 'Example' |
| [//]: # 'Example1' |
|
|
| ```angular-ts |
| @Component({ |
| template: ` <list-component (endReached)="fetchNextPage()" /> `, |
| }) |
| export class Example { |
| query = injectInfiniteQuery(() => ({ |
| queryKey: ['projects'], |
| queryFn: async ({ pageParam }) => { |
| return lastValueFrom(this.projectsService.getProjects(pageParam)) |
| }, |
| })) |
| |
| fetchNextPage() { |
| // Do nothing if already fetching |
| if (this.query.isFetching()) return |
| this.query.fetchNextPage() |
| } |
| } |
| ``` |
|
|
| [//]: # 'Example1' |
| [//]: # 'Example3' |
|
|
| ```ts |
| query = injectInfiniteQuery(() => ({ |
| queryKey: ['projects'], |
| queryFn: fetchProjects, |
| getNextPageParam: (lastPage, pages) => lastPage.nextCursor, |
| getPreviousPageParam: (firstPage, pages) => firstPage.prevCursor, |
| })) |
| ``` |
|
|
| [//]: # 'Example3' |
| [//]: # 'Example4' |
|
|
| ```ts |
| query = injectInfiniteQuery(() => ({ |
| queryKey: ['projects'], |
| queryFn: fetchProjects, |
| select: (data) => ({ |
| pages: [...data.pages].reverse(), |
| pageParams: [...data.pageParams].reverse(), |
| }), |
| })) |
| ``` |
|
|
| [//]: # 'Example4' |
| [//]: # 'Example8' |
|
|
| ```ts |
| injectInfiniteQuery(() => ({ |
| queryKey: ['projects'], |
| queryFn: fetchProjects, |
| initialPageParam: 0, |
| getNextPageParam: (lastPage, pages) => lastPage.nextCursor, |
| getPreviousPageParam: (firstPage, pages) => firstPage.prevCursor, |
| maxPages: 3, |
| })) |
| ``` |
|
|
| [//]: # 'Example8' |
| [//]: # 'Example9' |
|
|
| ```ts |
| injectInfiniteQuery(() => ({ |
| queryKey: ['projects'], |
| queryFn: fetchProjects, |
| initialPageParam: 0, |
| getNextPageParam: (lastPage, allPages, lastPageParam) => { |
| if (lastPage.length === 0) { |
| return undefined |
| } |
| return lastPageParam + 1 |
| }, |
| getPreviousPageParam: (firstPage, allPages, firstPageParam) => { |
| if (firstPageParam <= 1) { |
| return undefined |
| } |
| return firstPageParam - 1 |
| }, |
| })) |
| ``` |
|
|
| [//]: # 'Example9' |
|
|
