如何在构造函数中使用注入的对象? [英] How can I use an injected object in the constructor?

问题描述

我在Extbase扩展中有一个服务类，并希望使用ObjectManager在构造函数中创建对象的实例.

I have a service class in my Extbase extension and want to use the ObjectManager to create an instance of an object in the constructor.

/**
 * @var \TYPO3\CMS\Extbase\Object\ObjectManagerInterface
 * @inject
 */
protected $objectManager;

public function __construct() {
    $this->standaloneView = $this->objectManager->get('TYPO3\CMS\Fluid\View\StandaloneView');
    $this->standaloneView->setFormat('html');
}

不幸的是，这不会因错误Call to a member function get() on null而失败，因为注入的类在构造函数中似乎不可用.如何在构造函数中使用注入的类?

Unfortunately this doesn't fails with an error Call to a member function get() on null because the injected class doesn't seem to be available in the constructor. How can I use an injected class in the constructur?

推荐答案

要实现这一点，我可以使用所谓的构造函数注入.将ObjectManagerInterface定义为构造函数的参数，然后由Extbase自动注入:

To achieve this, I can use so-called constructor injection. The ObjectManagerInterface is defined as an argument of the constructor and then automatically injected by Extbase:

/**
 * @var \TYPO3\CMS\Extbase\Object\ObjectManagerInterface
 */
protected $objectManager;

public function __construct(\TYPO3\CMS\Extbase\Object\ObjectManagerInterface $objectManager) {
    $this->objectManager = $objectManager;
    $this->standaloneView = $this->objectManager->get('TYPO3\CMS\Fluid\View\StandaloneView');
    $this->standaloneView->setFormat('html');
}

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