我在将 EntityManger 注入 Symfony2 twig-extension 时遇到问题。我做了以下工作:
我注册了一个新的树枝扩展并创建了一个类。所有这些都在起作用。现在我想访问数据库,并尝试注入原则EntityManager。我的第一步是将 EM 作为参数添加到构造函数中:
use XYZBlubBundleUtilsSessionHelper;
class SessionHelperExtension extends Twig_Extension
{
private $em;
private $conn;
protected $sessionHelper;
public function __construct(DoctrineORMEntityManager $em, XYZBlubBundleUtilsSessionHelper $sessionHelper) {
$this->em = $em;
$this->conn = $em->getConnection();
$this->sessionHelper = $sessionHelper;
}
[...]
}
?>
然后我向service.yaml添加了以下行:
twig.extension.sessionHelper:
class: XYZBlubBundleExtensionsSessionHelperExtension
arguments: [@session_helper, @doctrine.orm.entity_manager]
tags:
- { name: twig.extension }
我自己的服务"会话助手"被注入没有问题,但实体管理器始终是"空"。我在这里做错了什么?
编辑:我得到以下异常:
Catchable Fatal Error: Argument 2 passed to
XYZBlubBundleExtensionsSessionHelperExtension::__construct() must be an instance of
DoctrineORMEntityManager, none given,
called in /.../Symfony/app/cache/dev/appDevDebugProjectContainer.php on line 2918 and
defined in /.../Symfony/src/XYZ/BlubBundle/Extensions/SessionHelperExtension.php line 12
public function __construct(
DoctrineORMEntityManager $em,
XYZBlubBundleUtilsSessionHelper $sessionHelper
) {
是错误的 — 您需要保持与yml
相同的顺序:
public function __construct(
XYZBlubBundleUtilsSessionHelper $sessionHelper,
DoctrineORMEntityManager $em
) {
更新
试试这个: http://www.coderelic.com/2012/06/querying-the-database-from-a-twig-extension-in-symfony-2/