我有一个与另一个实体具有OneTo多关系的实体，当我持久化父实体时，我想确保子实体不包含重复项。
这是我一直在使用的类，折扣集合不应包含给定客户端的两个同名产品。
我有一个客户实体，其中包含一系列折扣：
/**
* @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;
}
如您所见，我尝试将UniqueEntity用于Discount类，问题在于验证器似乎只检查数据库上加载的内容（为空），因此当实体被持久化时，我得到“SQLSTATE[23000]：完整性约束违规”。
我检查了Collection约束，它似乎只处理字段的集合，而不是实体。
还有All验证器，它允许您定义要应用于每个实体的约束，但不能应用于整个集合。
在持久化到数据库之前，除了每次编写自定义验证器或编写回调验证器之外，我需要知道整体上是否有实体集合约束。
我为此创建了一个自定义约束/验证器。
它使用“全部”断言验证表单集合，并接受一个可选参数：属性的属性路径以检查实体相等性。
（它适用于Symfony 2.1，要使其适应Symfony 2.0，请检查答案的末尾）：
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;
}
和验证者：
#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[] = $value;
}
}
在你的例子中，你会这样使用它：
use Acme\DemoBundle\Validator\Constraints as AcmeAssert;
// ...
/**
* @ORM\OneToMany(targetEntity="Discount", mappedBy="client", cascade={"persist"}, orphanRemoval="true")
* @Assert\All(constraints={
* @AcmeAssert\UniqueInCollection(propertyPath ="product")
* })
*/
对于Symfony 2.0，通过以下方式更改验证函数：
public function isValid($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
}
这是一个像UniqueEntity一样使用多个字段的版本。如果多个对象具有相同的值，则验证失败。
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;
}
}
}
对于Symfony 4.3（仅测试版本），您可以使用我的自定义验证器。首选的使用方式是作为验证集合的注释：
use App\Validator\Constraints as App;
...
/**
* @ORM\OneToMany
*
* @App\UniqueProperty(
* propertyPath="entityProperty"
* )
*/
private $entities;
Julien和我的解决方案之间的区别在于，我的约束是在经过验证的Collection上定义的，而不是在Collection本身的元素上。
约束：
#src/Validator/Constraints/UniqueProperty.php
<?php
namespace App\Validator\Constraints;
use Symfony\Component\Validator\Constraint;
/**
* @Annotation
*/
class UniqueProperty extends Constraint
{
public $message = 'This collection should contain only elements with uniqe value.';
public $propertyPath;
public function validatedBy()
{
return UniquePropertyValidator::class;
}
}
验证器：
#src/Validator/Constraints/UniquePropertyValidator.php
<?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 UniquePropertyValidator extends ConstraintValidator
{
/**
* @var \Symfony\Component\PropertyAccess\PropertyAccessor
*/
private $propertyAccessor;
public function __construct()
{
$this->propertyAccessor = PropertyAccess::createPropertyAccessor();
}
/**
* @param mixed $value
* @param Constraint $constraint
* @throws \Exception
*/
public function validate($value, Constraint $constraint)
{
if (!$constraint instanceof UniqueProperty) {
throw new UnexpectedTypeException($constraint, UniqueProperty::class);
}
if (null === $value) {
return;
}
if (!\is_array($value) && !$value instanceof \IteratorAggregate) {
throw new UnexpectedValueException($value, 'array|IteratorAggregate');
}
if ($constraint->propertyPath === null) {
throw new \Exception('Option propertyPath can not be null');
}
$propertyValues = [];
foreach ($value as $key => $element) {
$propertyValue = $this->propertyAccessor->getValue($element, $constraint->propertyPath);
if (in_array($propertyValue, $propertyValues, true)) {
$this->context->buildViolation($constraint->message)
->atPath(sprintf('[%s]', $key))
->addViolation();
}
$propertyValues[] = $propertyValue;
}
}
}
