How to add _token csrf globally on Laravel Inertia?

Question

I have a project using Laravel Inertia and Vue Js. I'm having trouble with csrf tokens these days. I've read the documentation here https://inertiajs.com/csrf-protection, so maybe I should add the csrf token on every inertia request/response.

My question is, how to add this _token globally? So I don't need to add tokens to my vue file one by one because it has too many files.

My current script code on login.vue:

props: {
        errors: Object,
        session: Object,
        auth: Array
    },

    //define composition API
    setup(props) {
        //define form state
        const form = reactive({
            email: '',
            password: '',
        });

        //submit method
        const submit = () => {

            //send data to server
            Inertia.post('/login', {

                //data
                email: form.email,
                password: form.password,
                _token: props.auth.csrf
            });
        }

My HandleInertiaRequest (middleware):

<?php

namespace AppHttpMiddleware;

use IlluminateHttpRequest;
use InertiaMiddleware;

class HandleInertiaRequests extends Middleware
{
    /**
     * The root template that's loaded on the first page visit.
     *
     * @see https://inertiajs.com/server-side-setup#root-template
     * @var string
     */
    protected $rootView = 'app';

    /**
     * Determines the current asset version.
     *
     * @see https://inertiajs.com/asset-versioning
     * @param  IlluminateHttpRequest  $request
     * @return string|null
     */
    public function version(Request $request): ?string
    {
        return parent::version($request);
    }

    /**
     * Defines the props that are shared by default.
     *
     * @see https://inertiajs.com/shared-data
     * @param  IlluminateHttpRequest  $request
     * @return array
     */
    public function share(Request $request): array
    {
        return array_merge(parent::share($request), [
            //session
            'session' => [
                'status'    => fn () => $request->session()->get('status'),
                'success'   => fn () => $request->session()->get('success'),
                'error'     => fn () => $request->session()->get('error'),
            ],
            //user authenticated
            'auth' => [
                'user'          => $request->user() ?   $request->user() : null,
                'permissions'   => $request->user() ? $request->user()->getPermissionArray() : [],
                'csrf' => $request->session()->token()
            ],
            //route
            'route' => function () use ($request) {
                return [
                    'params' => $request->route()->parameters(),
                    'query' => $request->all(),
                ];
            },
        ]);
    }
}

Answer 1

Add the csrf token globally in your Middleware/HandleInertiaRequests.php file.

/**
 * Defines the props that are shared by default.
 *
 * @see https://inertiajs.com/shared-data
 * @param  \Illuminate\Http\Request  $request
 * @return array
 */
public function share(Request $request): array
{
    return array_merge(parent::share($request), [
          'csrf_token' => csrf_token(),
    ]);
}

Add instances to your form.

<input type="hidden" name="_token" :value="this.$page.props.csrf_token">

Finally, make the call, in the example below I use the Inertia useForm() function to log in the user.

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

  const form = useForm({
    email: String,
    password: String,
    _token: String,
    processing: false,
  });

  let submit = () => {
    form.processing = true
    
    form.post('/login')
  }
</script>