Respect\Validation custom Rule with PDO? - pdo

Question

I am learning Slim Framework v4 and decided to use Respect\Validation to validate inputted data and have hit a snag where I do not know how to inject the PDO into my custom rule I created.
The idea is to validate some inputs against the database if the provided data exist (or in another instances, if it was inputted correctly). In this specific case, I am tying to validate user's credentials for log in. My idea is this:
AuthController.php:
v::with('app\\Validators\\');
$userValidation = v::notBlank()->email()->length(null, 255)->EmailExists()->setName('email');
EmailExists() is my custom rule.
EmailExists.php:
namespace app\Validators;
use PDO;
use Respect\Validation\Rules\AbstractRule;
class EmailExists extends AbstractRule
{
protected $pdo;
public function __construct(PDO $pdo)
{
$this->pdo = $pdo;
}
public function validate($input, $id = null)
{
// a PDO query that checks if the email exists in database
}
}
But I get an error of Too few arguments to function app\Validators\EmailExists::__construct(), 0 passed and exactly 1 expected, which is somewhat expected since the AbstractRule does not have a PDO injected and my class extends it.
So how to inject the PDO interface so that I can use it in my custom rules?
Are you guys using another approach in validating this kind of data? Do note that I am writing an API, so the database validation is somewhat a must and after Googling for past two days, I have no solutions at hand.
I am also using a PHP-DI where I create PDO interface. This is my dependencies.php file:
declare(strict_types=1);
use DI\ContainerBuilder;
use Psr\Container\ContainerInterface;
use app\Handlers\SessionMiddleware;
return function (ContainerBuilder $containerBuilder) {
$containerBuilder->addDefinitions([
PDO::class => function (ContainerInterface $c) {
$settings = $c->get('settings')['db'];
$db = new PDO("mysql:host={$settings['host']};dbname={$settings['database']};charset={$settings['charset']},{$settings['username']},{$settings['password']}");
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$db->setAttribute(PDO::MYSQL_ATTR_INIT_COMMAND, "SET NAMES 'utf8',time_zone='{$offset}'");
$db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
return $db;
},
'session' => function(ContainerInterface $c) {
return new SessionMiddleware;
}
]);
};
And (part of) index.php:
declare(strict_types=1);
use DI\ContainerBuilder;
use Slim\Factory\AppFactory;
// Instantiate PHP-DI ContainerBuilder
$containerBuilder = new ContainerBuilder();
// Set up settings
$settings = require __DIR__ . '/../app/settings.php';
$settings($containerBuilder);
// Set up dependencies
$dependencies = require __DIR__ . '/../app/dependencies.php';
$dependencies($containerBuilder);
// Build PHP-DI Container instance
$container = $containerBuilder->build();
// Instantiate the app
AppFactory::setContainer($container);
$app = AppFactory::create();
// Register middleware
$middleware = require __DIR__ . '/../app/middleware.php';
$middleware($app);
// Register routes
$routes = require __DIR__ . '/../app/routes.php';
$routes($app);
// Add Routing Middleware
$app->addRoutingMiddleware();
// Run App & Emit Response
$response = $app->handle($request);
$responseEmitter = new ResponseEmitter();
$responseEmitter->emit($response);
Any help would be appreciated.

Answer 1

Use your user model to count the number of rows in the user table where there is a hit.
If it is not exactly 0, the check returns false, if it is exactly 0, the check passes.
So you don't have to include a PDO at this point. I use Slim 3 and that works quite well.
namespace app\Validators;
use Respect\Validation\Rules\AbstractRule;
class EmailAvailable extends AbstractRule {
/**
* #param $input
*
* #return bool
*/
public function validate ($sInput) {
return User::where('user_email', $sInput)->count() === 0;
}
}

Answer 2

class EmailAvailable extends AbstractRule {
/**
* #param $input
*
* #return bool
*/
public function validate ($sInput) {
return User::where('user_email', $sInput)->count() === 0;
}
}