upstream-tanstack-query/docs/framework/svelte/reference/functions/useIsMutating.md

id, title

id	title
useIsMutating	useIsMutating

function useIsMutating(filters?, queryClient?): ReactiveValue<number>;

Defined in: packages/svelte-query/src/useIsMutating.svelte.ts:28

useIsMutating is an optional hook that returns the number of mutations that your application is running (useful for app-wide loading indicators).

Parameters

filters?

MutationFilters<unknown, Error, unknown, unknown>

MutationFilters to narrow down which mutations to count.

queryClient?

QueryClient

Use this to use a custom QueryClient. Otherwise, the one from the nearest context will be used.

Returns

ReactiveValue<number>

A reactive value — read .current to get how many matching mutations are currently running.

Example

<script lang="ts">
  import { useIsMutating } from '@tanstack/svelte-query'

  // How many mutations matching the posts prefix are in progress?
  const isMutatingPosts = useIsMutating({ mutationKey: ['posts'] })
</script>

{#if isMutatingPosts.current}
  <span>Saving posts...</span>
{/if}