如何在symfony2中验证实体集合中的唯一实体

Question

我有一个与另一个实体具有OneToMany关系的实体,当我坚持父实体时,我想确保子项不包含重复项.

这是我一直在使用的类,折扣集合不应包含给定客户端具有相同名称的两个产品.

我有一个客户实体,有一系列折扣:

/**
 * @ORM\Entity
 */
class Client {

    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @ORM\Column(type="string", length=128, nullable="true")
     */
    protected $name;

    /**
     * @ORM\OneToMany(targetEntity="Discount", mappedBy="client", cascade={"persist"}, orphanRemoval="true")
     */
    protected $discounts;

}

/**
 * @ORM\Entity
 * @UniqueEntity(fields={"product", "client"}, message="You can't create two discounts for the same product")
 */
    class Discount {
        /**
         * @ORM\Id
         * @ORM\Column(type="string", length=128, nullable="true")
         */
        protected $product;

        /**
         * @ORM\Id
         * @ORM\ManyToOne(targetEntity="Client", inversedBy="discounts")
         * @ORM\JoinColumn(name="client_id", referencedColumnName="id")
         */
        protected $client;

        /**
         * @ORM\Column(type="decimal", scale=2)
         */
        protected $percent;
    }

我尝试使用UniqueEntity作为Discount类,你可以看到,问题是似乎验证器只检查数据库上加载了什么(它是空的),所以当实体被持久化时我得到一个"SQLSTATE [23000]:完整性约束违规".

我已经检查了Collection约束购买它似乎只处理字段集合,而不是实体.

还有All validator,它允许您定义要应用于每个实体的约束,但不能定义整个集合.

除了每次编写自定义验证器或编写Callback验证器之外,我需要知道在持久化到数据库之前是否存在整体实体集合约束.

Answer 1

我为此创建了一个自定义约束/验证器.

它使用" All "断言验证表单集合,并采用可选参数:属性的属性路径以检查实体相等性.

(这是针对Symfony 2.1,使其适应Symfony 2.0检查答案的结尾):

有关创建自定义验证约束的更多信息,请查看Cookbook

约束:

#src/Acme/DemoBundle/Validator/constraint/UniqueInCollection.php
<?php

namespace Acme\DemoBundle\Validator\Constraint;

use Symfony\Component\Validator\Constraint;

/**
* @Annotation
*/
class UniqueInCollection extends Constraint
{
    public $message = 'The error message (with %parameters%)';
    // The property path used to check wether objects are equal
    // If none is specified, it will check that objects are equal
    public $propertyPath = null;
}

验证者:

#src/Acme/DemoBundle/Validator/constraint/UniqueInCollectionValidator.php
<?php

namespace Acme\DemoBundle\Validator\Constraint;

use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Symfony\Component\Form\Util\PropertyPath;

class UniqueInCollectionValidator extends ConstraintValidator
{

    // We keep an array with the previously checked values of the collection
    private $collectionValues = array();

    // validate is new in Symfony 2.1, in Symfony 2.0 use "isValid" (see below)
    public function validate($value, Constraint $constraint)
    {
        // Apply the property path if specified
        if($constraint->propertyPath){
            $propertyPath = new PropertyPath($constraint->propertyPath);
            $value = $propertyPath->getValue($value);
        }

        // Check that the value is not in the array
        if(in_array($value, $this->collectionValues))
            $this->context->addViolation($constraint->message, array());

        // Add the value in the array for next items validation
        $this->collectionValues[] = $value;
    }
}

在你的情况下,你会像这样使用它:

use Acme\DemoBundle\Validator\Constraints as AcmeAssert;

// ...

/**
 * @ORM\OneToMany(targetEntity="Discount", mappedBy="client", cascade={"persist"}, orphanRemoval="true")
 * @Assert\All(constraints={
 *     @AcmeAssert\UniqueInCollection(propertyPath ="product")
 * })
 */

对于Symfony 2.0,请通过以下方式更改验证功能:

public function isValid($value, Constraint $constraint)
{
        $valid = true;

        if($constraint->propertyPath){
            $propertyPath = new PropertyPath($constraint->propertyPath);
            $value = $propertyPath->getValue($value);
        }

        if(in_array($value, $this->collectionValues)){
            $valid = false;
            $this->setMessage($constraint->message, array('%string%' => $value));
        }

        $this->collectionValues[] = $value;

        return $valid

}

Answer 2

这是一个使用多个字段的版本，就像 UniqueEntity 一样。如果多个对象具有相同的值，验证将失败。

用法：

/**
* ....
* @App\UniqueInCollection(fields={"name", "email"})
*/
private $contacts;
//Validation fails if multiple contacts have same name AND email

约束类...

<?php
namespace App\Validator\Constraints;

use Symfony\Component\Validator\Constraint;

/**
 * @Annotation
 */
class UniqueInCollection extends Constraint
{
    public $message = 'Entry is duplicated.';
    public $fields;

    public function validatedBy()
    {
        return UniqueInCollectionValidator::class;
    }
}

验证器本身......

<?php

namespace App\Validator\Constraints;

use Symfony\Component\PropertyAccess\PropertyAccess;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Symfony\Component\Validator\Exception\UnexpectedTypeException;
use Symfony\Component\Validator\Exception\UnexpectedValueException;

class UniqueInCollectionValidator extends ConstraintValidator
{
    /**
     * @var \Symfony\Component\PropertyAccess\PropertyAccessor
     */
    private $propertyAccessor;

    public function __construct()
    {
        $this->propertyAccessor = PropertyAccess::createPropertyAccessor();
    }

    /**
     * @param mixed $collection
     * @param Constraint $constraint
     * @throws \Exception
     */
    public function validate($collection, Constraint $constraint)
    {
        if (!$constraint instanceof UniqueInCollection) {
            throw new UnexpectedTypeException($constraint, UniqueInCollection::class);
        }

        if (null === $collection) {
            return;
        }

        if (!\is_array($collection) && !$collection instanceof \IteratorAggregate) {
            throw new UnexpectedValueException($collection, 'array|IteratorAggregate');
        }

        if ($constraint->fields === null) {
            throw new \Exception('Option propertyPath can not be null');
        }

        if(is_array($constraint->fields)) $fields = $constraint->fields;
        else $fields = [$constraint->fields];


        $propertyValues = [];
        foreach ($collection as $key => $element) {
            $propertyValue = [];
            foreach ($fields as $field) {
                $propertyValue[] = $this->propertyAccessor->getValue($element, $field);
            }


            if (in_array($propertyValue, $propertyValues, true)) {

                $this->context->buildViolation($constraint->message)
                    ->atPath(sprintf('[%s]', $key))
                    ->addViolation();
            }

            $propertyValues[] = $propertyValue;
        }

    }
}