Symfony Forms: How to save properties of related entity? - symfony-forms

Question

I'm new to Symfony and have very basic question regarding forms and relations.
The goal is to build a form to save/ edit an object based on an entity which includes a property related to another entity. Unfortuanetely I have no idea how to define the fields in the buildForm method to save/ edit the properties of this related entity.
Entity\Artist.php
use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
/**
* #ORM\Entity
* #ORM\Table(name="artist")
* #UniqueEntity("name")
*/
class Artist {
const THEMES_ENABLED = true;
/**
* #ORM\Column(type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #ORM\Column(type="string", length=150, unique=true, nullable=false)
* #Assert\NotBlank()
*/
private $name;
/**
* #ORM\OneToOne(targetEntity="ArtistBiography", mappedBy="artist")
*/
private $artistBiography;
// Getter & Setter ...
}
Entity\ArtistBiography.php
**
* #ORM\Entity
* #ORM\Table(name="artist_biography")
*/
class ArtistBiography {
/**
* #ORM\Column(type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #ORM\OneToOne(targetEntity="Artist", inversedBy="artistBiography")
* #ORM\JoinColumn(name="artist_id", referencedColumnName="id")
*/
private $artist;
/**
* #ORM\Column(type="string", length=150, unique=false, nullable=false)
*/
private $headline;
/**
* #ORM\Column(type="string", length=150, nullable=false)
*/
private $text;
// Getter & Setter ...
}
I use this custom FormType to render:
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\Extension\Core\Type\TextType;
//use Doctrine\ORM\EntityRepository;
use Symfony\Bridge\Doctrine\Form\Type\EntityType;
use Symfony\Component\OptionsResolver\OptionsResolver;
class ArtistType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options) {
$builder
->add('name', TextType::class)
}
public function configureOptions(OptionsResolver $resolver) {
$resolver->setDefaults(array(
'data_class' => 'Entity\Artist',
));
}
}
How can I add the Fields for the properties 'artistBiography.headline' (TextType) and 'artistBiography.text' (TextareaType)?