[英]Call to a parent class member from child without calling constructor dependencies
我有我的基本控制器和我的內容控制器像下面一樣擴展它,我Call to a member function error() on null
收到Call to a member function error() on null
的Call to a member function error() on null
所以我的問題是:
我必須調用父構造函數嗎?
如果“是”,那么最好提供服務,因為父控制器有一些注入的依賴項,我不想通過調用父構造函數來注入自己
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 $exception;
}
}
您不需要調用構造函數。 但是如果你想使用它,你確實需要設置$logger
屬性。
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;
}
}
有了上面的內容,您不再需要調用parent::__construct()
。 但這只是一種很好的做法,無痛無害:
做就是了:
public function __construct(
LoggerInterface $logger,
ContentRepository $contentRepository,
BreadcrumbInterface $breadcrumbService
) {
$this->contentRepository = $contentRepository;
$this->breadcrumbService = $breadcrumbService;
parent::__construct($logger);
}
但是如果BaseController
的唯一目的是提供一些日志記錄方法,那么在ContentController
簡單地注入記錄器服務並直接使用它可能會更好。
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