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12.15.2. 区块中的 Dependency Injection
在之前的文章中,我们已经讨论了什么是 Services、Dependency Injection (DI),以及如何在控制器中使用它们:
12.15. Services 和 Dependency Injection
12.15.1. 控制器中的 Dependency Injection
在本文中,我们将演示如何通过 DI 向区块类中添加服务:
/modules/custom/drupalbook/src/Plugin/Block/CartBlock.php:
<?php
namespace Drupal\drupalbook\Plugin\Block;
use Drupal\commerce_cart\CartProviderInterface;
use Drupal\Core\Block\BlockBase;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
/**
* 提供一个购物车区块.
*
* @Block(
* id = "commerce_cart",
* admin_label = @Translation("Cart"),
* category = @Translation("Commerce")
* )
*/
class CartBlock extends BlockBase implements ContainerFactoryPluginInterface {
/**
* 购物车提供者.
*
* @var \Drupal\commerce_cart\CartProviderInterface
*/
protected $cartProvider;
/**
* 实体类型管理器.
*
* @var \Drupal\Core\Entity\EntityTypeManagerInterface
*/
protected $entityTypeManager;
/**
* 构造一个新的 CartBlock.
*
* @param array $configuration
* 插件实例的配置数组.
* @param string $plugin_id
* 插件实例的插件 ID.
* @param mixed $plugin_definition
* 插件实现定义.
* @param \Drupal\commerce_cart\CartProviderInterface $cart_provider
* 购物车提供者.
* @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
* 实体类型管理器.
*/
public function __construct(array $configuration, $plugin_id, $plugin_definition, CartProviderInterface $cart_provider, EntityTypeManagerInterface $entity_type_manager) {
parent::__construct($configuration, $plugin_id, $plugin_definition);
$this->cartProvider = $cart_provider;
$this->entityTypeManager = $entity_type_manager;
}
/**
* {@inheritdoc}
*/
public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
return new static(
$configuration,
$plugin_id,
$plugin_definition,
$container->get('commerce_cart.cart_provider'),
$container->get('entity_type.manager')
);
}
/**
* 构建购物车区块.
*
* @return array
* 一个渲染数组.
*/
public function build() {
...
/** @var \Drupal\commerce_order\Entity\OrderInterface[] $carts */
$carts = $this->cartProvider->getCarts();
...
}
}
首先我们在区块类中添加 ContainerFactoryPluginInterface 接口:
class CartBlock extends BlockBase implements ContainerFactoryPluginInterface {
然后定义属性,用来保存服务对象:
protected $cartProvider;
protected $entityTypeManager;
接着我们在构造函数中设置插件的标准参数:
public function __construct(array $configuration, $plugin_id, $plugin_definition) {
parent::__construct($configuration, $plugin_id, $plugin_definition);
在插件构造函数的标准参数之后,我们还需要传递服务对象所需的参数:
public function __construct(array $configuration, $plugin_id, $plugin_definition, CartProviderInterface $cart_provider, EntityTypeManagerInterface $entity_type_manager) {
parent::__construct($configuration, $plugin_id, $plugin_definition);
$this->cartProvider = $cart_provider;
$this->entityTypeManager = $entity_type_manager;
}
在 create() 方法中,我们同样先传递插件的标准参数,再传递服务对象:
/**
* {@inheritdoc}
*/
public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
return new static(
$configuration,
$plugin_id,
$plugin_definition,
$container->get('commerce_cart.cart_provider'),
$container->get('entity_type.manager')
);
}
完成这些后,我们就可以通过 $this 来使用服务对象:
public function build() {
...
/** @var \Drupal\commerce_order\Entity\OrderInterface[] $carts */
$carts = $this->cartProvider->getCarts();
...
}