从子类调用父类成员而不调用构造函数依赖项

Question

I have my base controller and my content controller extending it like below, and I'm getting a Call to a member function error() on null so my question is:

Do I have to call the parent constructor?

If "yes" then is it better to have a service because the parent controller has some injected dependencies that I don't want to inject myself by calling the parent constructor

use Psr\Log\LoggerInterface;

class BaseController extends AbstractController
{
    /** @var LoggerInterface */
    protected $logger;

    
    /**
     * BaseController constructor.
     */
    public function __construct(LoggerInterface $logger)
    {
        $this->logger = $logger;
    }
}


class ContentController extends BaseController
{

private $contentRepository;
private $breadcrumbService;

public function __construct(
    ContentRepository $contentRepository,
    BreadcrumbInterface $breadcrumbService
) {
    $this->contentRepository = $contentRepository;
    $this->breadcrumbService = $breadcrumbService;
}

public function contentPage(...)
{
    try {
      ....
    } catch (\Throwable $exception) {
        $this->logger->error(...);
        throw $exception;
    }
}

Answer 1

You do not need to call the constructor. But you do need to set the $logger property if you want to use it.

class ContentController extends BaseController
{

    private $contentRepository;
    private $breadcrumbService;

    public function __construct(
        LoggerInterface $logger,
        ContentRepository $contentRepository,
        BreadcrumbInterface $breadcrumbService
    ) {
        $this->contentRepository = $contentRepository;
        $this->breadcrumbService = $breadcrumbService;
        $this->logger = $logger;
    }

}

With the above you no longer need to call parent::__construct() . But it's simply good practice, painless and harmless:

Just do:

public function __construct(
        LoggerInterface $logger,
        ContentRepository $contentRepository,
        BreadcrumbInterface $breadcrumbService
) {
    $this->contentRepository = $contentRepository;
    $this->breadcrumbService = $breadcrumbService;
    parent::__construct($logger);
}

But if the only purpose of BaseController is to provide some logging methods, it's probably better to simply inject the logger service in ContentController and use it directly.