# Server Helpers

Redirect after a form action, refresh a parent form, and update the browser.

Source: https://withastro-utils.github.io/docs/guides/forms/js-helpers/

Use `Astro.locals.forms` inside a Forms page with the [shared setup](https://withastro-utils.github.io/docs/guides/forms/getting-started/index.md).

## Show feedback before redirecting

```astro title="src/pages/finish.astro"
---
import { BButton, BindForm } from '@astro-utils/forms/forms.js';
import Layout from '../layouts/Layout.astro';

let message = '';

function finish() {
    message = 'Done. Returning to the home page in two seconds.';
    Astro.locals.forms.redirectTimeoutSeconds('/', 2);
}
---
<Layout>
    <span slot="title">Finish a task</span>
    <BindForm>
        <BButton onClick={finish}>Finish</BButton>
        <p role="status">{message}</p>
    </BindForm>
</Layout>
```

`redirectTimeoutSeconds` sends a browser action, so the user sees the rendered feedback before navigating. Use `redirect('/account')` in the callback when you want an immediate HTTP redirect instead.

## Refresh a parent after a child action

A form rerenders after its own action. Call `reloadState()` only when a nested form changes data shown by its parent. The [editable users example](https://withastro-utils.github.io/docs/guides/forms/loops-and-components/index.md) demonstrates deletion and the parent's count updating together.

For database-backed parent data, attach a loader to `bind.on.reloadState`. A reload does not run the original button callback again.

## Choose a helper

| Helper | Use it for |
| --- | --- |
| `redirect(url, status?)` | An immediate server redirect. |
| `redirectTimeoutSeconds(url, seconds?)` | Render feedback, then navigate in the browser. |
| `reloadState()` | Rerender a parent affected by a child action. |
| `updateSearchParams()` | Change several URL query values, then call the returned `redirect()`. |
| `updateOneSearchParam(key, value?, status?)` | Change or remove one query value and redirect. |
| `alert(message)` | Show a browser alert. Prefer inline feedback for ordinary validation. |
| `consoleLog(...values)` / `console(type, ...values)` | Log in the browser. |
| `callFunction(name, ...args)` | Call an existing browser function. |

## Stop a nested operation with a response

Use [ThrowOverrideResponse](https://withastro-utils.github.io/docs/reference/forms/advanced-responses/index.md) when a nested function must stop processing and return a response. Setting a redirect and throwing a response serve different control-flow needs; ordinary form callbacks usually only need the redirect helper.