Symfony2 & Doctrine2 : removeElement doesn't work - php

Question

I'm have a small project in Symfony2 and doctrine, and I'm trying to update 2 related entities:
Members & cars
$carMembers = $car->getMembers();
echo count($carMembers); // --> show 2
echo get_class(carMembers[0]); // --> show MyCars\WSBundle\Entity\Member
$car->removeMember($member);
$em->persist($car);
$em->flush();
$carMembers= $car->getMembers();
echo count($carMembers); // --> show 1
echo get_class(carMembers[0]); // --> show MyCars\WSBundle\CarsController !!!
there is my Entities:
Car
/**
* #ORM\ManyToMany(targetEntity="Member", mappedBy="cars")
*/
private $members;
/**
* Remove Member
*
* #param MyCars\WSBundle\Entity\Member $member
*/
public function removeMember(\MyCars\WSBundle\Entity\Member $member)
{
$this->members->removeElement($member);
$member->removeCar($this);
}
Member
/**
* #ORM\ManyToMany(targetEntity="Car", cascade={"persist"})
* #ORM\JoinTable(name="cars_membres",
* joinColumns={#ORM\JoinColumn(name="member_id", referencedColumnName="member_id")},
* inverseJoinColumns={#ORM\JoinColumn(name="car_id", referencedColumnName="car_id")}
* )
*/
private $cars;

Answer 1

I think what you're looking for is orphanRemoval relation option.
#ORM\ManyToMany(targetEntity="Car", cascade={"persist"}, orphanRemoval=true)
So when you remove item from collection and flush entity manager it will remove relation record from database...

Answer 2

Make sure to initialise the ArrayCollection in the class constructor, if you want to use the functions add, contains or removeElement
<?php
// ...
use Doctrine\Common\Collections\ArrayCollection;
class Car
{
/**
* #MongoDB\Id
*/
protected $members;
/**
* General constructor
*/
public function __construct()
{
$this->members = new ArrayCollection();
}
/**
* #param Member $member
* #return $this
*/
public function addMember(Member $member)
{
if (!$this->hasMember($member)) {
$this->members->add($member);
}
return $this;
}
/**
* #param Member $member
* #return $this
*/
public function removeMember(Member $member)
{
if ($this->hasMember($member)) {
$this->members->removeElement($member);
}
return $this;
}
/**
* #return mixed
*/
public function getMembers()
{
return $this->tags;
}
/**
* #param Member $member
* #return mixed
*/
public function hasTag(Member $member)
{
return $this->members->contains($member);
}
}

Answer 3

Which Collection do you use? Do you use \Doctrine\ArrayCollecion?
Are you sure that you are removing the same member object instance?
removeElement() method removes an object from the collection only if it is the same instance.
here is the method (note the last parameter (true) in the array_search method:
public function removeElement($element)
{
$key = array_search($element, $this->_elements, true);
if ($key !== false) {
unset($this->_elements[$key]);
return true;
}
return false;
}