Symfony Entity check for ArrayCollection if already exists, then do update - symfony

Question

For a Collection, I want to check if a new added Part already exists in the database. And if so, that it'll be overwritten with the new value.
/**
* Add Part
*/
public function addPart(\MyBundle\Entity\FooTypePart $Part)
{
$part->setProduct($this);
$this->part[] = $part;
return $this;
}
/**
*/
public function removePart(\MyBundle\Entity\FooTypePart $part)
{
$this->part->removeElement($part);
}
/**
* Get Part
* #return \Doctrine\Common\Collections\Collection
*/
public function getPart()
{
return $this->part;
}
/**
* Set Part
*/
public function setPart($part)
{
$this->part = $part;
return $this;
}
The Part Entity has: ID, Category_id (FK), Product_id (FK), Part (Collection)
It is possible at the moment to add a new Part with the same name, also when there is already a Part with the same Product_id AND Category_id.
Making Part unique isn't the fix, because Part can be used for many Products/Categories.
The following example already exists in the database, with a different 'Part'. So it should do a update command.
<?php
$part = new FooTypePart();
$part->setCategory($specification);
$part->setProduct($product);
$part->setPart('DifferentNamingThenCurrentOne');
$xx->addSpecificationValue($part);
How? :-)

Answer 1

Just use the UniqueEntity validator to find an already existant Item in the collection.
You can specify uniqueness using multiple properties or a repository method. This way you can search for items only having a unique combination of name, product-id and category-id.
Create a validation group i.e. "unique" and find the non-unique/existant entity in your collection by looking for invalid entities.
... then update the existing entity with your new value. You will probably need some extra logic because there might be multiple fields with the same name added to your form collection.