Fatal error: Call to undefined method contains() in Symfony 2.7 - symfony

Question

I have a problem of recognition constrains() method in Symfony2. I have a relationship between the groups & Roles entities: So a group must have a mandatory role and the role may or may not have one or more groups. So in my addRoles function ( Groups $grp) I have checked each time if the group has a role so we joust if not assigning a role. But when inserting,
I encounter a problem:
PHP Fatal error: Call to undefined method
MemberShipManagement\GroupsBundle\Entity\Roles::contains() in
/var/www/Project_Console/src/MemberShipManagement/GroupsBundle/Entity/Roles.php
on line 118,
Class Groups:
/**
* #var Roles $role
*
* #ORM\ManyToOne(targetEntity="Roles", inversedBy="groups")
* #ORM\JoinColumn(name="role_id", referencedColumnName="id", nullable=false)
*
* #Assert\Valid()
*/
protected $role;
Class Roles:
/**
* #var ArrayCollection $groups
*
* #ORM\OneToMany(targetEntity="Groups", mappedBy="role", cascade={"remove"} )
*#Assert\Valid()
*/
protected $groups;
/**
* Add group
* #param Groups $grp
*/
public function addRoles(Groups $grp) {
// $grp->setRole($this);
if (!$this->groups->contains($grp)) {
$this->groups->add($grp);
}
return $this;
}
/**
* Remove groups
* #param Groups $groups
*/
public function removeRoles(Groups $groups)
{
if ($this->groups->contains($groups)) {
$this->groups->removeElement($groups);
}
return $this;
}
public function __construct()
{
$this->groups = new ArrayCollection();
}
thank you :)

Answer 1

Maybe you could try to check if the data exists before calling the contains method like,
public function addRoles(Groups $grp) {
// $grp->setRole($this);
if ( !isEmpty($this->groups) ){
if (!$this->groups->contains($grp)) {
$this->groups->add($grp);
}
}
return $this;
}
since the error you get seems to be derived from the fact that $groups are not interpreted as ArrayCollection defined in doctrine.(if so, you could've called contains method defined there)
http://www.doctrine-project.org/api/common/2.4/class-Doctrine.Common.Collections.ArrayCollection.html
As long as other examples using contains method are found like this(https://groups.google.com/forum/#!topic/doctrine-user/i6IhBPHALkk) your approach looks correct.
Otherwise you could try to change $role to private instead of protected?