具有數據庫連接但沒有實體的Symfony2自定義驗證

Question

我只是在嘗試驗證具有一個字段“用戶名”的表單（不附加任何實體）。 我想檢查用戶名是否存在。 如果不是正確的消息，則必須在表單錯誤級別（或表單字段錯誤級別，我不在乎）中顯示。

這是我的控制器的相關部分：

$formGlobalSearch=$this->createFormBuilder()
->add('username', 'text', array('constraints' => new UsernameExists()))
->add('role', 'choice', array('choices' => $rolesListForForm,'required' => false, 'placeholder' => 'Choose a role', 'label' => false, ))
->add('submitUsername', 'submit', array('label' => 'Search username globally'))
->getForm();

$formGlobalSearch->handleRequest($request);

if ($formGlobalSearch->isValid())
    {
    // do something in the DB and refresh current page
    }

return $this->render(//all the stuff needed to render my page//);
}

這是service.yml的相關部分

validator.unique.UsernameExists:
    class: AppBundle\Validator\Constraints\UsernameExists
    tags:
        - { name: validator.constraint_validator, alias: UsernameExists }

這是驗證器類：

使用Symfony \\ Component \\ Validator \\ Constraint;

/**
 * @Annotation
 */
class UsernameExists extends Constraint
{
public $message = 'The username "%string%" does not exist.';

public function validatedBy()
{
    return 'UsernameExists';
}
}

這是驗證器：

<?php
namespace AppBundle\Validator\Constraints;

use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;

class UsernameExistsValidator extends ConstraintValidator
{
public function validate($value)
    {
    $globalUserToAdd = $this->getDoctrine()->getRepository('AppBundle:User')->findOneBy(
        array('username' => $value, 'enabled' => true)
        );

    if ($globalUserToAdd == null) //I did not find the user
        {
        $this->context->buildViolation($constraint->message)
            ->setParameter('%string%', $value)
            ->addViolation();
        }
    }
}

類和驗證器在目錄“ AppBundle \\ Validator \\ Constraints”中

我收到以下錯誤：

給定類型為“ Symfony \\ Component \\ Validator \\ ConstraintValidatorInterface”，“ AppBundle \\ Validator \\ Constraints \\ UsernameExists”的預期參數

我當然在控制器上有以下內容：

use AppBundle\Validator\Constraints\UsernameExists;

如果我將以下內容添加到service.yml

arguments: ["string"]

我得到錯誤：

沒有為約束AppBundle \\ Validator \\ Constraints \\ UsernameExists配置默認選項

Answer 1

嘗試更改：

public function validatedBy()
{
    return 'UsernameExists';
}

validator.unique.UsernameExists:
    class: AppBundle\Validator\Constraints\UsernameExists

至：

public function validatedBy()
{
    return 'UsernameExistsValidator';
}

validator.unique.UsernameExists:
    class: AppBundle\Validator\Constraints\UsernameExistsValidator

Answer 2

合並（部分）建議並在此處進行更多調試是最終代碼。

驗證器：

<?php
namespace AppBundle\Validator\Constraints;

use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Doctrine\ORM\EntityManager;

class UsernameExistsValidator extends ConstraintValidator
{

public function __construct(EntityManager $em) //added
{
    $this->em = $em;
}

public function validate($value, Constraint $constraint)
    {
    $em = $this->em;
    $globalUserToAdd = $em->getRepository('AppBundle:User')->findOneBy(
        array('username' => $value, 'enabled' => true)
        );

    if ($globalUserToAdd == null) //I did not find the user
        {
        $this->context->buildViolation($constraint->message)
            ->setParameter('%string%', $value)
            ->addViolation();
        }
    }
}

service.yml

validator.unique.UsernameExists:
    class: AppBundle\Validator\Constraints\UsernameExistsValidator
    arguments: [ @doctrine.orm.entity_manager, "string"]
    tags:
        - { name: validator.constraint_validator, alias: UsernameExists }