Sonata Admin One to Many relations - symfony

Question

I started working with SonataAdmin Bundle today, and i can't figure out OneToMany relations. My User can follow(obserwowane) offerts
Entities:
class Obserwowane {
/**
* #ORM\Id
* #ORM\Column(type="integer")
* #ORM\GeneratedValue(strategy="AUTO")
*/
protected $id;
/**
* #ORM\ManyToOne(targetEntity="Oferty",inversedBy="obserwowane")
* #ORM\JoinColumn(name="oferta", referencedColumnName="id_oferty", onDelete="CASCADE")
*/
protected $oferta;
/**
*
* #ORM\ManyToOne(targetEntity="User", inversedBy="obserwowane")
* #ORM\JoinColumn(name="user", referencedColumnName="id")
*/
protected $user;
}
.
class User {
/**
* #ORM\OneToMany(targetEntity="Obserwowane", mappedBy="user")
*/
public $obserwowane;
}
.
class Oferty {
/**
* #ORM\OneToMany(targetEntity="Obserwowane", mappedBy="oferta")
*/
protected $obserwowane;
}
My servies.yml -> http://pastebin.com/biNCLhNt
I would like to display followed offers in User form in SonataAdminBundle. I would like also to have it editable.
protected function configureFormFields(FormMapper $formMapper)
{
$formMapper
->add('id', 'integer', array('label' => 'id'))
->add('username', 'text', array('label' => 'Username'))
->add('email', 'text', array('label' => 'e-mail'))
->add('password', 'text', array('label' => 'Password'))
;
}

Answer 1

Define obserwowane as ArrayCollection and add getter and setter methods so sonata will use them to operate with Obserwowane array of entities.
use Doctrine\Common\Collections\ArrayCollection;
class user{
// ...
public function __construct()
{
$this->obserwowane = new ArrayCollection;
}
/**
* Get obserwowane
*
* #return \Doctrine\Common\Collections\Collection
*/
public function getObserwowane ()
{
return $this->obserwowane ;
}
public function setObserwowane (ArrayCollection $obserwowane )
{
$this->obserwowane = $obserwowane ;
return $this;
}
/**
* Add Obserwowane
*
* #param Obserwowane $obserwowane
* #return Obserwowane
*/
public function addObserwowane (Obserwowane $obserwowane )
{
$this->obserwowane[] = $obserwowane;
return $this;
}
/**
* Remove Obserwowane
*
* #param Obserwowane $obserwowane
*/
public function removeObserwowane(Obserwowane $obserwowane)
{
$this->obserwowane->removeElement($obserwowane);
}
}
Finally add obserwowane field in formMapper
$formMapper
->add('obserwowane')
Update
To add or remove user for Obserwowane entity add those functions to Obserwowaneclass
class Obserwowane{
// ..
/**
* Set User
*
* #param User $user
* #return User
*/
public function setUser($user)
{
$this->user = $user;
return $this;
}
/**
* Get User
*
* #return User
*/
public function getUser()
{
return $this->user;
}
}
And in sonata
$formMapper
->add(user)