How to validate unique entities in an entity collection in symfony2

Question

I have an entity with a OneToMany relation to another entity, when I persist the parent entity I want to ensure the children contain no duplicates.

Here\'s the class

Answer 1

I can't manage to make the previous answer works on symfony 2.6. Because of the following code on l. 852 of RecursiveContextualValidator, it only goes once on the validate method when 2 items are equals.

if ($context->isConstraintValidated($cacheKey, $constraintHash)) {
    continue; 
} 

So, here is what I've done to deals with the original issue :

On the Entity :

* @AcmeAssert\UniqueInCollection(propertyPath ="product")

Instead of

* @Assert\All(constraints={
*     @AcmeAssert\UniqueInCollection(propertyPath ="product")
* })

On the validator :

public function validate($collection, Constraint $constraint){

    $propertyAccessor = PropertyAccess::getPropertyAccessor(); 

    $previousValues = array();
    foreach($collection as $collectionItem){
        $value = $propertyAccessor->getValue($collectionItem, $constraint->propertyPath);
        $previousSimilarValuesNumber = count(array_keys($previousValues,$value));
        if($previousSimilarValuesNumber == 1){
            $this->context->addViolation($constraint->message, array('%email%' => $value));
        }
        $previousValues[] = $value;
    }

}

Instead of :

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

    if($constraint->propertyPath){
        $propertyAccessor = PropertyAccess::getPropertyAccessor(); 
        $value = $propertyAccessor->getValue($value, $constraint->propertyPath);
    }

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

    $this->collectionValues[] = $value;

    return $valid

}