RoleInterface throws "call on a non-object" error - symfony

Question

I'm working over Symfony 2.0.16
I have in my UserProvider the method getRoles
public function getRoles()
{
/**
* #var \Doctrine\Common\Collections\ArrayCollection $rol
*/
return $this->rol->toArray();
}
and my Rol entity has the role interface
class Rol implements \Symfony\Component\Security\Core\Role\RoleInterface
//...
public function getRole()
{
return $this->getName();
}
but when I try to login I get the following error
Fatal error: Call to a member function getRole() on a non-object in C:\Users\julian\Code\parqueadero\vendor\symfony\src\Symfony\Bundle\SecurityBundle\DataCollector\SecurityDataCollector.php on line 57
Reading the class SecurityDataCollector, the error is thrown by a Closure
array_map(function ($role){ return $role->getRole();}, $token->getRoles()
Now I change this to
array_map(function ($role){ var_dump($role); return $role->getRole();}, $token->getRoles()
To my surprise, $role is a object Rol but I can't understand why I get the error.

Answer 1

I found the solution the problem is a bug in PHP 5.4 (the php i'm using) serialize method the github user yoannch proposed this solution, is overwrite the serialize/unserialize methods using json_encode/json_decode methods
class User implements \Serializable
//...
/**
* Serializes the content of the current User object
* #return string
*/
public function serialize()
{
return \json_encode(
array($this->username, $this->password, $this->salt,
$this->rol, $this->id));
}
/**
* Unserializes the given string in the current User object
* #param serialized
*/
public function unserialize($serialized)
{
list($this->username, $this->password, $this->salt,
$this->rol, $this->id) = \json_decode(
$serialized);
}
only need change the correct name properties

Answer 2

I had the same problem (Windows, PHP 5.4.5), updated to 5.4.7 and it still did not work. Nevertheless, I came up with a workaround that needs less maintenance (when overwriting the serialization functions as described in the article you mentioned, you'll have to keep them up to date when adding/removing fields). So far it works for me, I hope there are no other problems resulting from the workaround I might have forgotten. Just alter the User's getRoles() function like that:
/**
* #inheritDoc
*/
public function getRoles()
{
$roles = array();
foreach ($this->userRoles as $role) {
$roles[] = $role->getRole();
}
return $roles;
}
Note that $role->getRole() returns the role name as a String (e.g. ROLE_ADMIN).

Answer 3

solution of this problem is very simple.
All problems associated with circular references at yours User and Role objects.
So you have not to serialize User::$roles and Role::$users fields.
Look at Symfony\Component\Security\Core\Authentication\Token\AbstractToken::__construct() and Symfony\Component\Security\Core\Authentication\Token\AbstractToken::serialize().
How you can see, Symfony take your user's roles by invoking UserInterface::getRoles() before serialization. And serialize User and Roles separately.
You have to implement \Serializable interface in User and Role entities.
Example:
/**
* Acme\Bundle\UserBundle\Entity\User
*
* #ORM\Table(name="`user`")
* #ORM\Entity(repositoryClass="Acme\Bundle\UserBundle\Entity\UserRepository")
*/
class User implements AdvancedUserInterface, EquatableInterface, \Serializable
{
/**
* #var integer $id
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string $username
*
* #ORM\Column(type="string", length=30, unique=true)
*/
private $username;
/**
* #var string $email
*
* #ORM\Column(type="string", length=100, unique=true)
*/
private $email;
/**
* #var string $salt
*
* #ORM\Column(type="string", length=40)
*/
private $salt;
/**
* #var string $password
*
* #ORM\Column(type="string", length=128)
*/
private $password;
/**
* #var boolean $isActive
*
* #ORM\Column(type="boolean")
*/
private $isActive;
/**
* User's roles. (Owning Side)
*
* #var ArrayCollection
*
* #ORM\ManyToMany(targetEntity="Role", inversedBy="users")
*/
private $roles;
// .....
/**
* #see \Serializable::serialize()
*/
public function serialize()
{
/*
* ! Don't serialize $roles field !
*/
return \serialize(array(
$this->id,
$this->username,
$this->email,
$this->salt,
$this->password,
$this->isActive
));
}
/**
* #see \Serializable::unserialize()
*/
public function unserialize($serialized)
{
list (
$this->id,
$this->username,
$this->email,
$this->salt,
$this->password,
$this->isActive
) = \unserialize($serialized);
}
}
/**
* Acme\Bundle\UserBundle\Entity\Role
*
* #ORM\Table(name="role")
* #ORM\Entity
*
*/
class Role implements RoleInterface, \Serializable
{
/**
* #var integer $id
*
* #ORM\Column(type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string $role
*
* #ORM\Column(name="role", type="string", length=20, unique=true)
*/
private $role;
/**
* Users in group (Inverse Side)
*
* #var ArrayCollection
*
* #ORM\ManyToMany(targetEntity="User", mappedBy="roles")
*/
private $users;
// .....
/**
* #see \Serializable::serialize()
*/
public function serialize()
{
/*
* ! Don't serialize $users field !
*/
return \serialize(array(
$this->id,
$this->role
));
}
/**
* #see \Serializable::unserialize()
*/
public function unserialize($serialized)
{
list(
$this->id,
$this->role
) = \unserialize($serialized);
}
}
And all will be serialized/unserialized correctly.
See discus at https://github.com/symfony/symfony/issues/3691
See also:
http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/cookbook/entities-in-session.html#serializing-entity-into-the-session