After upgrading to Drupal 10, running the coding standards check suggested that I could use DI in my validation constraints.
For example, this simple one:
<?php
declare(strict_types=1);
namespace Drupal\my_module\Plugin\Validation\Constraint;
use Drupal\Core\Logger\LoggerChannelFactoryInterface;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
/**
* Validates the DateTimeMidnightOnly constraint.
*/
class DateTimeMidnightOnlyValidator extends ConstraintValidator {
/**
* {@inheritdoc}
*/
public function validate(mixed $value, Constraint $constraint): void {
foreach ($value as $item) {
if (!$this->isMidnight($item->value)) {
$item_value = $item->value;
\Drupal::logger('my_custom_error_channel')->error("Invalid midnight timestamp! $item_value");
$this->context->addViolation($constraint->notMidnight, ['%value' => $item_value]);
}
}
}
/**
* Is the DateTime string midnight?
*
* @param string $value
* The DateTime string.
*
* @returns bool
* TRUE if it is a midnight string.
*/
private function isMidnight(string $value): bool {
return str_ends_with($value, 'T00:00:00');
}
}
So I tried injecting the logger:
/**
* Logger factory.
*
* @var \Drupal\Core\Logger\LoggerChannelFactoryInterface
*/
protected LoggerChannelFactoryInterface $loggerFactory;
/**
* Constructs DateTimeMidnightOnlyValidator.
*
* @param \Drupal\Core\Logger\LoggerChannelFactoryInterface $logger_factory
* The logger factory.
*/
public function __construct(LoggerChannelFactoryInterface $logger_factory) {
$this->loggerFactory = $logger_factory;
}
This results in an error:
ArgumentCountError: Too few arguments to function
Drupal\custom_module\Plugin\Validation\Constraint\DateTimeMidnightOnlyValidator::__construct(),
0 passed in
/var/www/html/web/core/lib/Drupal/Core/DependencyInjection/ClassResolver.php
on line 31 and exactly 1 expected
So I need to pass the argument-- how do I do that? For custom services I know I can use mymodule.services.yml, and for totally overriding core services I can use MyModuleServiceProvider.php, but what about validation constraints?
