Symfony 4，无法实例化抽象类App \ Security \ FormLoginAuthenticator。 守护

Question

I am following this tutorial about authentication

I have a custom security class called FormLoginAuthenticator.php

use Symfony\Component\Security\Guard\Authenticator\AbstractFormLoginAuthenticator;
use Symfony\Component\Security\Core\Security;

abstract class FormLoginAuthenticator extends AbstractFormLoginAuthenticator
{
protected $router;
protected $enconder;
public function __construct(RouterInterface $router, UserPasswordEncoderInterface $encoder)
{
    $this->router = $router;
    $this->encoder = $encoder;
}
}

which extends the AbstractFormLoginAuthenticator from the symfony guard component which itself is a abstract class. However I keep gettting

Cannot instantiate abstract class App\Security\FormLoginAuthenticator

I have read about extending abstract classes and if my custom class has more than 1 abstract method I should use prefix the class keyword with `abstract. However I get that error when I added the abstract keyword. How to get around this problem

Answer 1

You don't have abstract method in your

FormLoginAuthenticator

, so this class shouldn't be abstract. The only abstract method is from its parent, but when you extend abstract parent, you don't define your new class as Abstract, unless there is next child, which is extending it. You can't instantiate abstract classes, thats where your error comes from. You have to define your class as normal or final Small example here - https://3v4l.org/4MQpU#v560