Flash data

Flash data is stored for the next page render, typically right before a redirect. Inertia exposes it as page.flash on the client, separate from the props.

use Crenspire\Inertia\Flash\InertiaFlash;

$this->flash->flash('message', 'Profile updated.');

// Several values at once:
$this->flash->flash(['message' => 'Saved.', 'level' => 'success']);

return $this->inertia->redirect('/profile');

flash is only included in the page when there is data, and the data is removed once a page has been rendered.

Reading flash data

React

import { usePage } from '@inertiajs/react'

export default function FlashMessage() {
  const { flash } = usePage()

  return flash?.message ? <p className="alert">{flash.message}</p> : null
}

Vue

<script setup>
import { usePage } from '@inertiajs/vue3'

const page = usePage()
</script>

<template>
  <p v-if="page.flash?.message" class="alert">{{ page.flash.message }}</p>
</template>

What InertiaFlash stores

Method	Effect on the next render
errors(array $errors, string $bag = 'default')	Merged into the errors prop, see Forms
flash(string|array $key, mixed $value = null)	Added to page.flash
clearHistory()	Sets clearHistory, see History encryption
preserveFragment()	Keeps the URL fragment across the redirect, see Redirects

All methods return the same instance, so calls can be chained.

Storage

InertiaFlash writes to a FlashStoreInterface:

• In Yii3 with yiisoft/session, the package registers SessionFlashStore.
• Without a session package, implement the interface, as shown in Without Yii3.
• In tests, use ArrayFlashStore.

Values stay in the store until a page is rendered. If a redirect leads to a non-Inertia page, the values appear on the next Inertia page instead.