# transaction

Signature
`transaction(store?: Store): (callback: TransactionFn, name?: string) => void`

valdres-svelte
Batch multiple writes into a single commit

Returns a transaction runner bound to the current context store, captured at component initialization. That capture is what makes it safe to call from an event handler — Svelte throws `lifecycle_outside_component` if you call `getContext` inside a handler. Writes inside the callback commit together, so subscribers and selectors observe one atomic update. Forwards core's optional devtools `name`.

## Usage

```svelte
<script lang="ts">
    import { transaction } from "valdres-svelte"
    import { countAtom } from "$lib/state"

    const txn = transaction()

    const buyTwo = () =>
        txn(({ get, set }) => set(countAtom, get(countAtom) + 2))
</script>

<button onclick={buyTwo}>Buy two</button>
```

Pass an explicit `store` to bind the runner to a specific store instead of the context store.

## See also

- [setValdresContext](https://valdres.dev/svelte/setValdresContext) — provide the store the runner binds to
- [scope](https://valdres.dev/svelte/scope) — scoped child store