Symfony2 Custom Validator with EntityManager not working - php

Question

I am trying to build a validator that will check against the database for some values. For this I need to inject inside a service the entityManager and give an alias to my Validation method as documented in Symfony official documentation.
The problem is that after doing everything by the book I am still getting an error saying that the entityManager is null:
Catchable Fatal Error: Argument 1 passed to XXX\CommonBundle\Validator\Constraints\IsSingleEntryValidator::__construct() must be an instance of Doctrine\ORM\EntityManager, none given, called in /var/www/XXX/vendor/symfony/symfony/src/Symfony/Bundle/FrameworkBundle/Validator/ConstraintValidatorFactory.php on line 71 and defined
My service:
XXX.validators.is_single_entry:
class: XXX\CommonBundle\Validator\Constraints\IsSingleEntryValidator
arguments:
- "#doctrine.orm.default_entity_manager"
tags:
- { name: validator.constraint_validator, alias: single_entry_validation }
And the validator class:
class IsSingleEntryValidator extends ConstraintValidator
{
/**
* #var EntityManager
*/
protected $em;
/**
* Constructor
*
* #param EntityManager $em
*/
public function __construct(EntityManager $em)
{
$this->em = $em;
}
public function validate($value, Constraint $constraint)
{
...
}
public function validateBy()
{
return 'single_entry_validation';
}
}
And the use of validator:
/**
* #ORM\Column(name="is_primary", type="boolean", nullable=true)
* #SiteAssert\IsSingleEntry(message="validator.single.entry")
*/
protected $isPrimary;

Answer 1

#Ragdata - doctrine.orm.default_entity_manager Doctrine\ORM\EntityManager
There are actually 2 mistakes in my code.
Calling of validatedBy() function
This function should be called inside the IsSingleEntry class and not IsSingleEntryValidator
Method name should be diferent
I call the method validateBy() but the correct function name should be validatedBy()
So the code should be looking like this now:
IsSingleEntry
class IsSingleEntry extends Constraint
{
public $message = "The value already exists in the database";
/**
* #return string
*/
public function validatedBy()
{
return 'single_entry_validation';
}
}
IsSingleEntryValidator
class IsSingleEntryValidator extends ConstraintValidator
{
/**
* #var EntityManager
*/
protected $em;
/**
* Construct
*
* #param EntityManager $em
*/
public function __construct(EntityManager $em)
{
$this->em = $em;
}
/**
* Validate
*
* #param mixed $value
* #param Constraint $constraint
*/
public function validate($value, Constraint $constraint)
{
$oActiveExists = $this->em->getRepository('DatabaseBundle:Languages')->findOneByIsPrimary(true);
if ($oActiveExists) {
$this->context->buildViolation($constraint->message)
->addViolation();
}
}
}