How can I define PDO in SLIM Framework so that PhpStorm doesn't throw 'method not found in class' warnings?

So I stick PDO into my SLIM using this:

$container['dbh'] = function($container) {
    $config = $container->get('settings')['pdo'];
    $dsn = "{$config['engine']}:host={$config['host']};dbname={$config['database']};charset={$config['charset']}";
    $username = $config['username'];
    $password = $config['password'];

    return new PDO($dsn, $username, $password, $config['options']);
};

However, every time I use $this->dbh->execute() (or some other PDO method), PhpStorm warns me method 'execute' not found in class

Realistically it doesn't make a difference but I'd like my PhpStorm to stop warning me about things that it doesn't need to.

Solution

This is mostly an answer adding to @rickdenhaan's comment.

I noticed that you're using $this, which implies you have a class somewhere.

You can typehint dynamic/fake properties in a class like so:

/**
 * @property PDO $dbh
 */
class MyApp {
}

For more help, read the PHPDoc documentation, eg here.

In some situations, you might not be able to influence the original class being instantiated. In that case, you can have a stub file; basically a class used only for type hinting:

// Let's assume you cannot modify this class.
class App {}

// This is the stub class, we declare it as abstract to avoid instantiation by mistake.
// We make it extend `App` to get metadata from there.
abstract class AppStub extends App {
    /** @var PDO */
    public $dbh;
}


// ...later on in your code..
/** @var AppStub $this */

// tada!
$this->dbh->execute();

Controller classes approach

Your main app + routing:

$app = new \Slim\App();
$app->get('/', \YourController::class . ':home');
$app->get('/contact', \YourController::class . ':contact');

And your controller:

class YourController 
{
   protected $container;

   // constructor receives container instance
   public function __construct(ContainerInterface $container) {
       $this->container = $container;
   }

   public function home($request, $response, $args) {
        $this->getDb()->execute();   // no IDE errors anymore!
        return $response;
   }

   public function contact($request, $response, $args) {
        return $response;
   }

   /**
    * @return PDO
    */
   protected function getDb()
   {
       return $this->container->get('dbh');
   }
}