Implement Phalcon 4 Database Existence validator (similar to Uniqueness) - phalcon

Question

Often I need to validate if given value is existing in certain column (attribute) of a table (model).
This can be useful in foreign keys of a model, to check if the given values exists.
Most probably the validation logic can be mostly the same as for Uniqueness, except the comparison here can be something like > 0.
A possible usage scenario could be like below:
$validator->add(
'organization_id',
new ExistenceOnDbValidator(
[
'model' => Organization::class,
'expr'=> ' id = %s ',
'excludeNullValue'=> true,
'message' => 'Organization does not exist.',
]
)
);

Answer 1

Finally I implemented myself a validator called ExistenceOnDbValidator and it works fine.
Usage
$validator = new Validation();
$validator->add(
'organization_id',
new ExistenceOnDbValidator(
[
'model' => Organization::class,
'expr' => ' id = %s ',
'ignoreNullValue' => false,
'message' => 'Selected organization does not exist.',
]
)
);
Implenentation
use Phalcon\Messages\Message;
use Phalcon\Validation;
use Phalcon\Validation\AbstractValidator;
use Phalcon\Validation\ValidatorInterface;
class ExistenceOnDb extends AbstractValidator implements ValidatorInterface
{
public function validate(Validation $validator, $attribute): bool
{
$expr = $this->getOption('expr');
$model = $this->getOption('model');
$value = $validator->getValue($attribute);
$ignoreNullValue = true;
if ($this->hasOption('ignoreNullValue')) {
$ignoreNullValue = $this->getOption('ignoreNullValue');
}
if ((is_null($value) || empty($value)) && $ignoreNullValue == true) {
return true;
}
$expr = sprintf(
$expr,
$value,
);
$result = $model::findFirst($expr);
if ((is_null($result) || empty($result))) {
$message = $this->getOption('message');
$validator->appendMessage(new Message($message));
return false;
}
return true;
}
}