| --- |
| id: queries |
| title: Queries |
| ref: docs/framework/react/guides/queries.md |
| replace: |
| { |
| 'React': 'Angular', |
| 'react-query': 'angular-query', |
| 'promise': 'promise or observable', |
| 'custom hooks': 'services', |
| 'the `useQuery` hook': '`injectQuery`', |
| '`useQuery`': '`injectQuery`', |
| "TypeScript will also narrow the type of data correctly if you've checked for pending and error before accessing it.": 'TypeScript will only narrow the type when checking boolean signals such as `isPending` and `isError`.', |
| } |
| --- |
| |
| [//]: # 'Example' |
|
|
| ```ts |
| import { injectQuery } from '@tanstack/angular-query-experimental' |
| |
| export class TodosComponent { |
| info = injectQuery(() => ({ queryKey: ['todos'], queryFn: fetchTodoList })) |
| } |
| ``` |
|
|
| [//]: # 'Example' |
| [//]: # 'Example2' |
|
|
| ```ts |
| result = injectQuery(() => ({ queryKey: ['todos'], queryFn: fetchTodoList })) |
| ``` |
|
|
| [//]: # 'Example2' |
| [//]: # 'Example3' |
|
|
| ```angular-ts |
| @Component({ |
| selector: 'todos', |
| standalone: true, |
| template: ` |
| @if (todos.isPending()) { |
| <span>Loading...</span> |
| } @else if (todos.isError()) { |
| <span>Error: {{ todos.error()?.message }}</span> |
| } @else { |
| <!-- We can assume by this point that status === 'success' --> |
| @for (todo of todos.data(); track todo.id) { |
| <li>{{ todo.title }}</li> |
| } @empty { |
| <li>No todos found</li> |
| } |
| } |
| `, |
| }) |
| export class PostsComponent { |
| todos = injectQuery(() => ({ |
| queryKey: ['todos'], |
| queryFn: fetchTodoList, |
| })) |
| } |
| ``` |
|
|
| [//]: # 'Example3' |
|
|
| If booleans aren't your thing, you can always use the `status` state as well: |
|
|
| [//]: # 'Example4' |
|
|
| ```angular-ts |
| @Component({ |
| selector: 'todos', |
| standalone: true, |
| template: ` |
| @switch (todos.status()) { |
| @case ('pending') { |
| <span>Loading...</span> |
| } |
| @case ('error') { |
| <span>Error: {{ todos.error()?.message }}</span> |
| } |
| <!-- also status === 'success', but "else" logic works, too --> |
| @default { |
| <ul> |
| @for (todo of todos.data(); track todo.id) { |
| <li>{{ todo.title }}</li> |
| } @empty { |
| <li>No todos found</li> |
| } |
| </ul> |
| } |
| } |
| `, |
| }) |
| class TodosComponent {} |
| ``` |
|
|
| [//]: # 'Example4' |
| [//]: # 'Materials' |
| [//]: # 'Materials' |
|
|
