symfony2：验证取决于查询

Question

在使用表单更新对象之后，对于某个字段（foo）中的某个值，我想检查是否存在具有特定属性值的持久子对象。

所以我创建了一个自定义验证器作为参数传递原则，但是..如何传递对象（或对象的id）和一定的值foo来创建查询？

这是我的代码：

class ChildCategoryHasItsOwnPageValidator extends ConstraintValidator 
{ 
    protected $doctrine; 

    public function __construct(RegistryInterface $doctrine) 
    { 
     $this->doctrine = $doctrine; 
    } 


    public function validate($value, Constraint $constraint) 
    { 
     //... 
    } 
} 

---

Placas\FrontendBundle\Entity\Category: 
    properties: 
     ownPage: 
      - Placas\FrontendBundle\Validator\Constraints\ChildCategoryHasItsOwnPage: ~ 

---

/** 
* @Annotation 
*/ 
class ChildCategoryHasItsOwnPage extends Constraint 
{ 
    public $message = 'This category has a child category with an own page. You can not define an own page for this category.'; 

    public function validatedBy() 
    { 
     return "child_category_has_its_own_page"; 
    } 
} 

---

Placas\FrontendBundle\Entity\Category: 
    properties: 
     ownPage: 
      - Placas\FrontendBundle\Validator\Constraints\ChildCategoryHasItsOwnPage: ~ 

Answer 1

我想这会帮助你：http://symfony.com/doc/current/reference/constraints/Callback.html

它应该这样对你： （Symfony的2.4版本）

你的配置：

Placas\FrontendBundle\Entity\Category: 
    constraints: 
     - Callback: [validate] 

在你的实体：

use Symfony\Component\Validator\ExecutionContextInterface; 

class Category 
{ 
    public function validate(ExecutionContextInterface $context) 
    { 
     $children = $this->getChildren(); // assuming you have this relationship and its getter 
     foreach ($children as $child) 
     { 
      if ($child->foo != '') // or whatever test you want to make 
      { 
       $context->addViolationAt(
        'foo', 
        'This category has a child category with an own page. You can not define an own page for this category.', 
        array(), 
        null 
       ); 
      } 
     } 
    } 
}