Best way to add custom validation method in a CodeIgniter 4 module - codeigniter-4

Question

Here is the problem.
I've got a module called Contact. It lives in a directory called modules/Contact. I registered a namespace Contact for the module in app/Config/Autoload.php. Everything seems to load fine. Now I want to use a custom validation method to validate input coming from a form field. My question is about the best way to do it. My approach is as follows: According to CI4 documentation, Validation class loads App/Config/Validation.php when used for validation. In the file there is public property called $ruleSets, which points to an array, it contains names of classes with validation rules. I want to add my own class with validation methods to this array. According to CI4 documentation on validation, configuration classes, and their public properties in App/Config/ can be updated using registrars. So, I crated one such registrar, a class, in my Contact module. It lives in Contact\Config\Registrar.php . The class has public static method Validation, which returns an array with an updated $ruleSet. The new value is an array and contains all the standard validation class names + my validation class name. The trouble is public static method Validation I added in my registrar seems not to change the value of $ruleSet defined in App/Config/. Contact/Config/Registrar.php is loaded, but Validation method it contains is not called. So, what's the best method to add custom validation rules without having to updated files which live beyond my module? There is very little on registrars in CI4 documentation. Have I misunderstood how they work and how they are supposed to be used?

Answer 1

I had the same problem and my solution was to extend the validation class (better solutions are always welcome).
For example I wanted to write my own Auth module and use my own set of rules. My custom validation class lives under acme/Auth/Config/AuthValidation.php
<?php
namespace Acme\Auth\Config;
use Config\Validation;
class AuthValidation extends Validation
{
public $login = [
'username' => 'required',
'password' => 'required',
];
}
This way all validation rules in your main app are inherited.
And you would use this code in your controller to validate:
<?php
namespace Acme\Auth\Controllers;
use CodeIgniter\Controller;
use Acme\Auth\Config\AuthValidation as AuthValidation;
class Auth extends Controller
{
public function login()
{
//Instantiate the new AuthValidation class
$authValidationConfig = new AuthValidation();
//Since the validation class is a config for the validation service we set it for the validation service
$authValidation = \Config\Services::validation($authValidationConfig);
//Set the login rule from our AuthValidation class
$authValidation->setRuleGroup('login');
//Validate the request against our login rule
if($authValidation->withRequest($this->request)->run())
{
return 'Success';
}
else
{
return 'Failure';
}
}
}
It may be not the best solution because I'm pretty new to CodeIgniter but this is how I found my way around it.
Sidenote: The main problem seems to be that the class passed to the validation service constructor has to be an instance of "Config\Validation" so I had to extend it. But there might be other ways around it.
Feel free to correct me :)