Access Doctrine Entity Manager in custom Twig Extension in ZF2 - php

Question

I am using ZfcTwig module from https://github.com/ZF-Commons/ZfcTwig
Reference used: http://symfony.com/doc/current/cookbook/templating/twig_extension.html
Using above link, I was able to create a custom Twig Extension. In this class, I want to access the Entity Manager to fetch some data from database.
I am registering the custom extension via following code in module.config.php -
'zfctwig' => array(
'extensions' => array(
'Application\Extension\MyCustomTwigExtension'
)
)
But as I want to access a Doctrine Entity Manager in this class, I tried by creating a closure -
'zfctwig' => array(
'extensions' => array(
'Application\Extension\MyCustomTwigExtension' => function($sm) {
$entityManager = $sm->get('doctrine.entitymanager.orm_default');
$ext = new Application\Extension\MyCustomTwigExtension();
$ext->setEntityManager($entityManager);
return $ext;
},
)
),
And this gives the error message as -
Catchable fatal error: Argument 1 passed to Twig_Environment::addExtension() must implement interface Twig_ExtensionInterface, instance of Closure given....
I have tried for same via factory -
'zfctwig' => array(
'extensions' => array(
'Application\Extension\MyCustomTwigExtension' => 'Application\Extension\MyCustomTwigExtensionFactory'
)
),
Error message -
Catchable fatal error: Argument 1 passed to Twig_Environment::addExtension() must implement interface Twig_ExtensionInterface, instance of Application\Extension\MyCustomTwigExtensionFactory given...
Any ideas on injecting dependency into twig extension? It may not be just Entity Manager but access to View Helpers, etc.
Edit: Contents of MyCustomTwigExtension file -
namespace Application\Extension;
class MyCustomTwigExtension extends \Twig_Extension {
protected $_eventManager;
public function setEntityManager($eventManager = null) {
$this->_eventManager = $eventManager;
}
public function getEntityManager() {
return $this->_eventManager;
}
public function getFilters() {
return array(
new \Twig_SimpleFilter('list', array($this, 'listFilter')),
);
}
public function listFilter($content = '') {
$repository = $this->getEntityManager()->getRepository('Application\Entity\User');
$models = $repository->findAll();
$html = '<ul>List Extension';
foreach ($models as $model) {
$html .= "<li>" . $model->getId() . ' ' . $model->getFullname() . "</li>";
}
$html .= '</ul>';
return $html;
}
public function getName() {
return 'list_extension';
}
}
Thanks.

Answer 1

The only problem you have is the following:
As mentioned in module.config.php#32 you cann add Extension via Factory, but the given namespace Application\Extension\MyCustomTwigExtensionFactory must exist as key in your service_manager-config.
So you could do the following:
'zfctwig' => array(
'extensions' => array(
'customTwig' => 'MyCustomTwigExtensionFactory'
)
),
'service_manager' => array(
'factories' => array(
'MyCustomTwigExtensionFactory' => 'Application\Extension\MyCustomTwigExtensionFactory'
)
)
And everything should be ok.

Answer 2

You can implement ServiceLocatorAwareInterface:
class MyCustomTwigExtension extends \Twig_Extension implements ServiceLocatorAwareInterface {
}
for implementation you can use trait: ServiceLocatorAwareTrait
and you can add method to get entity manager:
public function getEntityManager() {
if($this->entityManager === null) {
$this->entityManager = $this->getServiceLocator()->get(''doctrine.entitymanager.orm_default'')
}
return $this->entityManager;
}
and last thing: in configuration you should add:
'service_manager' => array(
'factories' => array(
'MyCustomTwigExtensionFactory' => function() { return new MyCustomTwigExtension(); }
)
)