Background Fetching Indicators
A query's status === 'pending' state is sufficient enough to show the initial hard-loading state for a query, but sometimes you may want to display an additional indicator that a query is refetching in the background. To do this, queries also supply you with an isFetching boolean that you can use to show that it's in a fetching state, regardless of the state of the status variable:
angular-ts
@Component({
selector: 'todos',
template: `
@if (todosQuery.isPending()) {
Loading...
} @else if (todosQuery.isError()) {
An error has occurred: {{ todosQuery.error().message }}
} @else if (todosQuery.isSuccess()) {
@if (todosQuery.isFetching()) {
Refreshing...
}
@for (todos of todosQuery.data(); track todo.id) {
<todo [todo]="todo" />
}
}
`,
})
class TodosComponent {
todosQuery = injectQuery(() => ({
queryKey: ['todos'],
queryFn: fetchTodos,
}))
}
@Component({
selector: 'todos',
template: `
@if (todosQuery.isPending()) {
Loading...
} @else if (todosQuery.isError()) {
An error has occurred: {{ todosQuery.error().message }}
} @else if (todosQuery.isSuccess()) {
@if (todosQuery.isFetching()) {
Refreshing...
}
@for (todos of todosQuery.data(); track todo.id) {
<todo [todo]="todo" />
}
}
`,
})
class TodosComponent {
todosQuery = injectQuery(() => ({
queryKey: ['todos'],
queryFn: fetchTodos,
}))
}
Displaying Global Background Fetching Loading State
In addition to individual query loading states, if you would like to show a global loading indicator when any queries are fetching (including in the background), you can use the useIsFetching hook:
angular-ts
import { injectIsFetching } from '@tanstack/angular-query-experimental'
@Component({
selector: 'global-loading-indicator',
template: `
@if (isFetching()) {
<div>Queries are fetching in the background...</div>
}
`,
})
export class GlobalLoadingIndicatorComponent {
isFetching = injectIsFetching()
}
import { injectIsFetching } from '@tanstack/angular-query-experimental'
@Component({
selector: 'global-loading-indicator',
template: `
@if (isFetching()) {
<div>Queries are fetching in the background...</div>
}
`,
})
export class GlobalLoadingIndicatorComponent {
isFetching = injectIsFetching()
}
