13 Laravel 11 Basics: Validation

Defining the Routes

First, let's assume we have the following routes defined in our routes/web.php file:

use App\Http\Controllers\PostController;
 
Route::get('/post/create', [PostController::class, 'create']);
Route::post('/post', [PostController::class, 'store']);

The GET route displays a form for the user to create a new blog post, while the POST route stores the new blog post in the database.

Creating the Controller

Next, let's look at a simple controller that handles incoming requests to these routes. We'll leave the store method empty for now:

namespace App\Http\Controllers;
 
use Illuminate\Http\Request;
use Illuminate\Http\RedirectResponse;
 
class PostController extends Controller
{
    public function create()
    {
        return view('post.create');
    }
 
    public function store(Request $request): RedirectResponse
    {
        // Validation logic will go here
    }
}

Writing the Validation Logic

Now we are ready to fill in our store method with the logic to validate the new blog post. To do this, we will use the validate method provided by the Illuminate\Http\Request object:

public function store(Request $request): RedirectResponse
{
    $validated = $request->validate([
        'title' => 'required|unique:posts|max:255',
        'body' => 'required',
    ]);
 
    // The blog post is valid...
    return redirect('/posts');
}

As you can see, the validation rules are passed into the validate method. If validation fails, an Illuminate\Validation\ValidationException will be thrown, and the proper error response will be automatically sent back to the user.

Displaying the Validation Errors

So, what if the incoming request fields do not pass the given validation rules? Laravel will automatically redirect the user back to their previous location and all validation errors and request input will be flashed to the session. An $errors variable is shared with all views, allowing you to display error messages conveniently:

<!-- resources/views/post/create.blade.php -->
@if ($errors->any())
    <ul>
        @foreach ($errors->all() as $error)
            <li>{{ $error }}</li>
        @endforeach
    </ul>
@endif

Form Request Validation

For more complex validation scenarios, you may wish to create a "form request". Form requests are custom request classes that encapsulate their own validation and authorization logic:

php artisan make:request StorePostRequest

The generated form request class will be placed in the app/Http/Requests directory. Each form request has two methods: authorize and rules.

Customizing the Error Messages

Laravel's built-in validation rules each have an error message located in your application's lang/en/validation.php file. You can change or modify these messages based on the needs of your application. For example:

public function messages(): array
{
    return [
        'title.required' => 'A title is required',
        'body.required' => 'A message is required',
    ];
}

Specifying Custom Attributes

To replace the :attribute placeholder in validation messages with custom attribute names, you may specify custom names in the attributes method:

public function attributes(): array
{
    return [
        'email' => 'email address',
    ];
}

Conclusion

Laravel 11 provides powerful and flexible validation features that help ensure the integrity of your application's data. By mastering these validation techniques, you can build robust and reliable web applications.

For more detailed information, refer to the official Laravel 11 Validation Documentation.