Symfony - embedded form won't display - symfony

Question

I'm trying to create a form to insert "questions" that can have one or more "answers". So I want to add an embed form for the Answer entity.
It seems to work because I see the Question form, but only the string "Answers" is displayed at the bottom of my form, not the fields.
Here is my controller action :
public function addQuestionAction(Category $category)
{
$question = new Question();
$form = $this->createForm(new QuestionType(), $question);
$request = $this->get('request');
if ($request->getMethod() === 'POST') {
$form->bind($request);
$question->setCategory($category);
if ($form->isValid()) {
$em = $this->getDoctrine()->getManager();
$em->persist($question);
$em->flush();
return $this->redirect($this->generateUrl('mycategory_questiondisplay',
array('id' => $question->getId())));
}
}
return $this->render('MyCategoryBundle:Question:add.html.twig',
array(
'form' => $form->createView(),
));
}
My QuestionType form :
<?php
namespace My\CategoryBundle\Form;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolverInterface;
class QuestionType extends AbstractType
{
/**
* #param FormBuilderInterface $builder
* #param array $options
*/
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('title')
->add('description')
->add('answers', 'collection', array(
'type' => new AnswerType(),
'allow_add' => true)
);
}
/**
* #param OptionsResolverInterface $resolver
*/
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'Iel\CategoryBundle\Entity\Question'
));
}
/**
* #return string
*/
public function getName()
{
return 'my_categorybundle_question';
}
}
My Question Entity :
<?php
namespace My\CategoryBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
/**
* Question
*
* #ORM\Table()
* #ORM\Entity(repositoryClass="My\CategoryBundle\Entity\QuestionRepository")
*/
class Question
{
/**
* #ORM\OneToMany(targetEntity="My\CategoryBundle\Entity\Answer",
mappedBy="question", cascade={"persist", "remove"})
*/
private $answers;
public function __construct()
{
$this->answers = new
\Doctrine\Common\Collections\ArrayCollection();
}
public function addAnswer(\My\CategoryBundle\Entity\Answer
$answer)
{
$this->answers[] = $answer;
$answers->setQuestion($this);
return $this;
}
public function removeAnswer(\My\CategoryBundle\Entity\Answer $answer)
{
$this->answers->removeElement($answer);
}
public function getAnswers()
{
return $this->answers;
}
public function setAnswers($answer)
{
$this->answer = $answer;
return $this;
}
/**
* #ORM\ManyToOne(targetEntity="My\CategoryBundle\Entity\Category",
inversedBy="question")
* #ORM\JoinColumns({
* #ORM\JoinColumn(name="category_id", referencedColumnName="id")
* })
*/
private $category;
/**
* Set category
*
#param My\CategoryBundle\Entity\Category $category
*/
public function setCategory(\My\CategoryBundle\Entity\Category $category)
{
$this->category = $category;
}
/**
* Get category
*
#return My\CategoryBundle\Entity\Category
*/
public function getCategory()
{
return $this->category;
}
/**
* Remove categories
**
#param My\CategoryBundle\Entity\Category $categories
*/
public function removeCategory(\My\CategoryBundle\Entity\Category $category)
{
$this->categories->removeElement($category);
}
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="titre", type="string", length=255)
*/
private $titre;
/**
* #var string
*
* #ORM\Column(name="description", type="text")
*/
private $description;
/**
* Get id
*
* #return integer
*/
public function getId()
{
return $this->id;
}
/**
* Set titre
*
* #param string $titre
* #return Question
*/
public function setTitre($titre)
{
$this->titre = $titre;
return $this;
}
/**
* Get titre
*
* #return string
*/
public function getTitre()
{
return $this->titre;
}
/**
* Set description
*
* #param string $description
* #return Question
*/
public function setDescription($description)
{
$this->description = $description;
return $this;
}
/**
* Get description
*
* #return string
*/
public function getDescription()
{
return $this->description;
}
}
And finally, the Answer entity :
<?php
namespace My\CategoryBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
/**
* Answer
*
* #ORM\Table()
* #ORM\Entity(repositoryClass="My\CategoryBundle\Entity\AnswerRepository")
*/
class Answer
{
/**
* #ORM\ManyToOne(targetEntity="My\CategoryBundle\Entity\Question",
inversedBy="answer")
* #ORM\JoinColumns({
* #ORM\JoinColumn(name="question_id", referencedColumnName="id")
* })
*/
private $question;
/**
* Set question
*
#param My\CategoryBundle\Entity\Question $question
*/
public function setQuestion(\My\CategoryBundle\Entity\Question $question)
{
$this->question = $question;
}
/**
* Get question
*
#return My\CategoryBundle\Entity\Question
*/
public function getQuestion()
{
return $this->question;
}
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="answer", type="text", nullable=true)
*/
private $answer;
/**
* Get id
*
* #return integer
*/
public function getId()
{
return $this->id;
}
/**
* Set answer
*
* #param string $answer
* #return Answer
*/
public function setAnswer($answer)
{
$this->answer = $answer;
return $this;
}
/**
* Get answer
*
* #return string
*/
public function getAnswer()
{
return $this->answer;
}
}
I'm really not able to find what's wrong in my form...

Answer 1

The problem is that your question does not have any answers yet. Hence no forms. Try
$question = new Question();
$question->addAnswer(new Answer());
That will show an empty answer form.
Look in the cookbook to see how to use javascript to add answers dynamically from within the browser.