Vue Adapter

The vue-pacer adapter connects Pacer scheduling utilities to Vue state and lifecycle management. It re-exports the core package, including utility classes, stateless functions, option types, and async retrying.

Installation#

pnpm add @tanstack/vue-pacer

The package is ESM-only and requires Node.js 20 or newer when running in Node.js.

Lifecycle and state#

Call composables during component setup or inside an active Vue effect scope. Disposing the scope stops option watchers and subscriptions and cleans up the utility. Read selected state through utility.state.value in JavaScript; Vue templates unwrap refs.

By default, the selected state is {}. Pass a selector to subscribe only to the fields your UI reads. The underlying store remains available for additional subscriptions.

API overview#

Example#

This counter coalesces rapid clicks into one update after 500 ms. Flush applies the latest pending count immediately.

<script setup lang="ts">
import { ref } from 'vue'
import { useDebouncer } from '@tanstack/vue-pacer'

const count = ref(0)
const debouncedCount = ref(0)
const debouncer = useDebouncer(
  (value: number) => {
    debouncedCount.value = value
  },
  { wait: 500 },
  (state) => ({ isPending: state.isPending }),
)
const state = debouncer.state
function increment() {
  debouncer.maybeExecute(++count.value)
}
</script>

<template>
  <button @click="increment">Increment</button>
  <p>Count: {{ count }}. Debounced: {{ debouncedCount }}.</p>
  <p>Pending: {{ state.isPending }}</p>
  <button @click="debouncer.flush()">Flush</button>
</template>

Child subscriptions#

Use utility.Subscribe to select state for a child slot without subscribing the owning component to those fields. The slot receives the selected value and releases its subscription when removed.

<debouncer.Subscribe
  :selector="(state) => ({ isPending: state.isPending })"
  v-slot="{ isPending }"
>
  <span>Pending: {{ isPending }}</span>
</debouncer.Subscribe>

Reactive options#

Pass a plain options object, property getters, or an options factory. The adapter evaluates top-level getters, while function-valued core options remain callbacks. Options update the existing utility; pending work, counters, and the store retain their identity.

Options retain the core partial-merge behavior. Omitting a key preserves the previous setting; explicitly passing undefined clears it. key, initialState, and initialItems initialize the utility once and do not recreate it on later updates.

Default options#

Wrap descendants in PacerProvider or call providePacerOptions during setup. Both accept defaults grouped by utility, such as { debouncer: { leading: true } }. Provider defaults remain reactive and local options take precedence.

Cleanup#

Debouncers, throttlers, and batchers cancel pending timers by default. Queuers stop processing. Async variants also abort active work. Synchronous rate limiters need no timer cleanup.

Set onUnmount to replace the default cleanup, for example to call flush() before leaving a page. The callback receives the adapter instance and its selected state. If you replace cleanup for an async utility, call its cancellation or abort methods when needed.

Event handlers and value helpers#

Use an instance method as the event handler: maybeExecute for debouncing, throttling, and rate limiting, or addItem for batching. The instance also provides control methods and state subscriptions.

State helpers return [value, setValue, utility]; value helpers return [value, utility]. Read the Vue ref through .value in JavaScript. Setters accept a new value or a functional update. Synchronous queue state helpers return [itemsAccessor, addItem, utility]. Async queue state helpers return [itemsAccessor, utility]; call utility.addItem() to enqueue an item. Queued value helpers return the last processed value, rather than the list of pending items.

Async utilities#

The five async utilities preserve typed results and core error behavior. Use onSuccess, onError, and onSettled for outcomes, and asyncRetryerOptions for retry configuration. abort() is cooperative: your operation must observe the supplied abort signal. See the individual async guides for scheduling and concurrency details.

Devtools#

Install @tanstack/vue-pacer-devtools and @tanstack/vue-devtools. Pass pacerDevtoolsPlugin() to the host's plugins prop. See the devtools setup for an example. The /production entry explicitly includes the panel in production builds.

API reference#

See the generated reference for signatures, options, and return types.