Symfony OneToOne relation render unique form - symfony

Question

I have an entity with too many fields and datas to be handled by MySQL.
So I made another entity to store contents and linked it to the parent entity with OneToOne relations.
Here an extract of my parent entity HomeContent
// ...
class HomeContent
{
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="locale", type="string", length=6)
*/
private $locale;
/**
* #var string
*
* #ORM\OneToOne(targetEntity="ContentBlock", cascade={"all"})
*/
private $healthIntro;
/**
* #var string
*
* #ORM\OneToOne(targetEntity="ContentBlock", cascade={"all"})
*/
private $desktopIntro;
/**
* #var string
*
* #ORM\OneToOne(targetEntity="ContentBlock", cascade={"all"})
*/
private $techIntro;
// ...
public function __construct()
{
$this->healthIntro = new ContentBlock();
$this->desktopIntro = new ContentBlock();
$this->techIntro = new ContentBlock();
// ...
My ContentBlockentity has one text field content with setter and getter.
Now I want to simply render my form with a textarea for each fields, what would be the best way to do it?
For now, they're rendered as select elements, I defined a ContentBlockType class with content field
// ...
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('content', 'textarea');
}
// ...
And a HomeContentType of course
// ...
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('title', 'text')
->add('metadescription', 'text')
->add('healthIntro', 'entity', array(
'class' => 'NavaillesMainBundle:ContentBlock'
))
// ...

Answer 1

First of all I suggest to keep with a rule to use JoinColumn()annotation. Example:
/**
* #var string
*
* #ORM\OneToOne(targetEntity="ContentBlock", cascade={"all"})
* #ORM\JoinColumn(name="desktop_intro_id", referencedColumnName="id")
*/
private $desktopIntro;
Answer:
I don't know whether my way is the best but I suggest that you create ContentBlockFormType and embedded it to your form. So the form of your HomeContent entity will be like this:
// ...
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('title', 'text')
->add('metadescription', 'text')
->add('desktopIntro', ContentBlockFormType::class, [
'label' => 'Desktop intro',
'required' => false,
])
->add('healthIntro', ContentBlockFormType::class, [
'label' => 'Health intro',
'required' => false,
])
->add('techIntro', ContentBlockFormType::class, [
'label' => 'Tech intro',
'required' => false,
])
}
// ...