Hello Dev,

While Laravel comes with a robust set of default validation rules like email, required, unique, and date, there are occasions when you may need to craft your own. I'll walk you through the process step by step.

In this example, let's fashion a custom validation rule named BirthYearRule. We'll incorporate an input text box for birth_year and ensure that users input a year between 1980 and the current year using our custom validation.

Steps to Create a Custom Validation Rule in Laravel 11:

Ensure you have Laravel 11 installed. If not, you can install it using Composer.

Set up a route to handle the form submission and validation.

Define our custom validation rule, BirthYearRule, to check if the birth year falls within the specified range.

Create a controller to handle the form submission and apply our custom validation rule.

Craft a view file containing the form with an input field for the birth year.

Once these steps are completed, you'll have a Laravel application equipped with a custom validation rule ensuring that users provide a birth year within the designated range.

If you haven't already, create a new Laravel project:

composer create-project laravel/laravel example-app

Open the routes/web.php file and define a route for displaying the form and another for handling the form submission:

<?php
  
use Illuminate\Support\Facades\Route;

use App\Http\Controllers\CustomValidationController;
      
/*
|--------------------------------------------------------------------------
| Web Routes
|--------------------------------------------------------------------------
|
| Here is where you can register web routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| contains the "web" middleware group. Now create something great!
|
*/

Route::get('custom-validation', [CustomValidationController::class, 'create']);
Route::post('custom-validation', [CustomValidationController::class, 'store'])->name('custom.validation.post');

Generate a custom validation rule using Artisan CLI:

php artisan make:rule BirthYearRule

This command creates a new rule class in the app/Rules directory. Open the generated BirthYearRule.php file and implement the logic for validating the birth year:

<?php

namespace App\Rules;

use Closure;
use Illuminate\Contracts\Validation\ValidationRule;

class BirthYearRule implements ValidationRule
{
    /**
     * Run the validation rule.
     *
     * @param  \Closure(string): \Illuminate\Translation\PotentiallyTranslatedString  $fail
     */
    public function validate(string $attribute, mixed $value, Closure $fail): void
    {
        if(!($value > 1980 & $value < date('Y'))){
            $fail('The :attribute must be between 1980 to '.date('Y').'.');
        }
    }
}

Create a controller to handle the form display and validation logic:

php artisan make:controller CustomValidationController

Add methods to show the form and validate the birth year:

<?php
  
namespace App\Http\Controllers;
  
use Illuminate\Http\Request;
use Illuminate\View\View;
use Illuminate\Http\RedirectResponse;
use App\Rules\BirthYearRule;
   
class CustomValidationController extends Controller
{
    /**
     * Show the application dashboard.
     *
     * @return \Illuminate\Http\Response
     */
    public function create(): View
    {
        return view('forms');
    }
        
    /**
     * Show the application dashboard.
     *
     * @return \Illuminate\Http\Response
     */
    public function store(Request $request): RedirectResponse
    {
        $validatedData = $request->validate([
                'name' => 'required',
                'birth_year' => [
                    'required',
                    new BirthYearRule()
                ]
            ]);
        
        /*
            $validatedData['password'] = bcrypt($validatedData['password']);
            $user = User::create($validatedData);
        */
            
        return back()->with('success', 'User created successfully.');
    }

Create a Blade template for the form under resources/views/form.blade.php:

<!DOCTYPE html>
<html>
<head>
    <title>How to Create a Custom Validation Rule in Laravel 11? -- ItErrorSolution.com</title>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>
<div class="container">
    <div class="card mt-5">
        <h3 class="card-header p-3">How to Create a Custom Validation Rule in Laravel 11? -- ItErrorSolution.com</h3>
        <div class="card-body">
            <form method="POST" action="{{ route('custom.validation.post') }}">
    
                {{ csrf_field() }}
            
                <div class="mb-3">
                    <label class="form-label" for="inputName">Name:</label>
                    <input 
                        type="text" 
                        name="name" 
                        id="inputName"
                        class="form-control @error('name') is-invalid @enderror" 
                        placeholder="Name">

                    @error('name')
                        <span class="text-danger">{{ $message }}</span>
                    @enderror
                </div>
             
                <div class="mb-3">
                    <label class="form-label" for="inputEmail">Birth Year:</label>
                    <input 
                        type="text" 
                        name="birth_year" 
                        id="inputEmail"
                        class="form-control @error('birth_year') is-invalid @enderror" 
                        placeholder="Birth Year">

                    @error('birth_year')
                        <span class="text-danger">{{ $message }}</span>
                    @endif
                </div>
           
                <div class="mb-3">
                    <button class="btn btn-success btn-submit">Submit</button>
                </div>
            </form>
        </div>
    </div>
</div>
</body>
</html>

Now, to run the Laravel application, please type the following command and press enter:

php artisan serve

Now, open your web browser and enter the provided URL to view the output of the application.

http://localhost:8000/custom-validation

Thank you for your encouragement! If you have any questions or need further assistance, feel free to ask. I'm here to help!