Symfony - Inject Entity Manager in EventSubscriber of form - php

Question

This is the first time I am working with EventListener of a form so I am struggling on how to inject EntityManager in it.
I have this formType called UserType and in this class I have an EventSubscriber AddDepartmentDegreeCourseFieldSubscriber which needs access to EntityManager
class UserType extends AbstractType
{
/**
* #param FormBuilderInterface $builder
* #param array $options
*/
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->addEventSubscriber(new AddProfileFieldSubscriber());
$builder->addEventSubscriber(new AddDepartmentDegreeCourseFieldSubscriber());
}
/**
* #param OptionsResolver $resolver
*/
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'AppBundle\Entity\User'
));
}
}
This is my services.yml
app.department_course_degree_subscriber:
class: AppBundle\Form\EventListener\AddDepartmentDegreeCourseFieldSubscriber
arguments: ["#doctrine.orm.entity_manager"]
tags:
- { name: kernel.event_subscriber }
The error I get is as following
Catchable Fatal Error: Argument 1 passed to
AppBundle\Form\EventListener\AddDepartmentDegreeCourseFieldSubscriber::__construct()
must be an instance of Doctrine\ORM\EntityManager, none given, called
in /Users/shairyar/Sites/oxford-portal/src/AppBundle/Form/UserType.php
on line 21 and defined
I know what the error means but I thought the service i registered in services.yml should inject the EntityManager so why I am getting this error? What am i missing here? Any help will be really appreciated.

Answer 1

It's because, you pass new instance of AddDepartmentDegreeCourseFieldSubscriber when building form. You need to pass instance from service container.
use AppBundle\Form\EventListener\AddDepartmentDegreeCourseFieldSubscriber;
class UserType extends AbstractType
{
private $addDepartmentDegreeCourseFieldSubscriber;
public function __construct(AddDepartmentDegreeCourseFieldSubscriber $subscriber)
{
$this->addDepartmentDegreeCourseFieldSubscriber = $subscriber;
}
/**
* #param FormBuilderInterface $builder
* #param array $options
*/
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->addEventSubscriber($this->addDepartmentDegreeCourseFieldSubscriber);
}
}
# app/config/services.yml
services:
app.department_course_degree_subscriber:
class: AppBundle\Form\EventListener\AddDepartmentDegreeCourseFieldSubscriber
arguments: ["#doctrine.orm.entity_manager"]
tags:
- { name: kernel.event_subscriber }
app.form.type.my_user_form:
class: AppBundle\Form\UserType
arguments: [ "#app.department_course_degree_subscriber" ]
tags:
- { name: form.type }