Embedded form in Symfony2 and saving to database - forms

Question

In my Symfony2 application, there are two entities: Address and Town. The Address entity has a 4-digit postal code property ("pcNum"), which refers to the id of a Town entity. An address can only have one postal code and hence refer to one town only (however the reverse is possible: a town could have more postal codes).
For both entities I have created a form called TownType and AddressType. Users can enter and save a Town (this works fine). The form for the Address entity allows users to fill in an address, including a postal code. The postal code is linked to the id of a Town entity.
However, when I try to persist a new Address entity retrieved from the AddressType form, I receive the MySql error that the pc_num field (pcNum in the entity) is empty:
SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'pc_num' cannot be null
(This is the field of the Address entity that should have contained a ref key to a Town.) Somehow its value is lost before persisting the Address entity. If I fill the field manually in my controller, regardless of the user input in the form, I can persist the new Address without the error. If I drop the link to the Town entity and use an unaware form field, I can also safe without error as long as the postal code happens to exist. But in the way it should be, using two forms and entity-association, I cannot get it to work. I have tried many different things over the past weeks and I am out of ideas. Below is my code. Feel free to comment on anything, maybe my whole approach is wrong.
This is my Town entity:
namespace Xx\xBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Check;
/**
*
* Xx\xBundle\Entity\Town
*
* #ORM\Table(name="lib_towns")
* #ORM\Entity
*/
class Town
{
#id
/**
* #ORM\Id
* #ORM\Column(type="integer", length="4", nullable=false)
* #ORM\GeneratedValue(strategy="AUTO")
* #Check\NotBlank()
* #Check\MaxLength(4)
*/
protected $id;
#name
/**
* #ORM\Column(name="name", type="string", length="100", nullable=true)
* #Check\NotBlank()
* #Check\MaxLength(100)
*/
protected $name;
//some more properties
#getters and setters
/**
* Set id
*
* #param integer $id
*/
public function setId($id)
{
$this->id = $id;
}
/**
* Get id
*
* #return integer $id
*/
public function getId()
{
return $this->id;
}
/**
* Set name
*
* #param string $name
*/
public function setName($name)
{
$this->name = $name;
}
/**
* Get name
*
* #return string $name
*/
public function getName()
{
return $this->name;
}
//some more getters ans setters
}
This is my Address entity:
namespace Xx\xBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Check;
use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
use Xx\xBundle\Entity\Town;
/**
*
* Xx\xBundle\Entity\Address
*
* #ORM\Entity
* #ORM\Table(name="addresses")
*/
class Address
{
#id
/**
* #ORM\Id
* #ORM\Column(type="integer", length="6", nullable=false)
* #ORM\GeneratedValue(strategy="AUTO")
* #Check\NotBlank()
* #Check\MaxLength(6)
*/
protected $id;
#town
/**
* #orm\OneToOne(targetEntity="town")
* #ORM\JoinColumn(name="pc_num", referencedColumnName="id", nullable=false)
*/
protected $town;
//some other properties...
#getters and setters
/**
* Set id
*
* #param integer $id
*/
public function setId($id)
{
$this->id = $id;
}
/**
* Get id
*
* #return integer $id
*/
public function getId()
{
return $this->id;
}
/**
* Set town entity linked to this address
*
*/
public function setTown(town $town = null)
{
$this->town = $town;
}
/**
* Get town entity linked to this address
*
*/
public function getTown()
{
return $this->town;
}
//some other functions...
}
Next, this is the form I've created for the Address:
namespace Xx\xBundle\Form\Type;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilder;
use Doctrine\ORM\EntityRepository;
class AddressType extends AbstractType
{
public function buildForm(Formbuilder $builder, array $options)
{
$builder->add('id', 'hidden'); //necessary for updates
$builder->add('town', 'entity', array
(
'label' => 'Postal code (4 digits):*',
'class' => 'XxxBundle:Town',
'query_builder' => function(EntityRepository $er) {
return $er->createQueryBuilder('t')
->orderBy('t.id', 'ASC'); },
//'empty_value' => '----',
'property'=> 'Id',
'property_path'=> false,
'expanded' => false,
'multiple' => false,
'required' => true
));
$builder->add('street', 'text', array
(
'label' => 'Street:*',
'required' => true
));
//some more fields...
}
public function getDefaultOptions(array $options)
{
return array(
'data_class' => 'Xx\xBundle\Entity\Address'
);
}
public function getName()
{
return 'address';
}
}
This is the relevant action function in my Address controller:
public function editAddressAction($id = null)
{
$em = $this->getDoctrine()->getEntityManager();
$address = new Address();
$isNew = is_null($id);
//this also tests positve after a form has been sent
if($isNew)
{
#fill address object with some defaults
$address->setCreated(new \DateTime("now"));
} else
{
#fill address object with existing db data
$address = $em->getRepository('XxxBundle:Address')->find($id);
}
#create form and fill it with address object data
$form = $this->createForm(new AddressType(), $address);
#if form sent: check input
$request = $this->get('request');
if ($request->getMethod() == 'POST')
{
$form->bindRequest($request); //calls setters
if ($form->isValid())
{
//if I leave the following lines in: no error (but also no sense)
//because the pcNum should be retrieved from the form
$pcNum = 2222;
$town = $em->getRepository('XxxBundle:Town')->find($pcNum);
$address->setTown($town);
//end
#persist and flush
$id_unknown = is_null($address->getId());
if($id_unknown)
{
#insert address
$em->persist($address);
} else
{
#update address
$address->setModified(new \DateTime("now"));
$em->merge($address);
}
#commit
$em->flush();
#get id of update or insert and redirect user
$address_id = $address->getId();
return $this->redirect($this->generateUrl('displayAddress', array('id'=>$address_id)));
}
}
return $this->render('XxxBundle:Forms:address.html.twig', array('form'=>$form->createView(), 'new' => $isNew, 'id' => $id));
}
To conclude, this is the relevant Twig snippet:
<form action="{{ path('addAddress') }}" method="post" {{ form_enctype(form) }}>
{{ form_errors(form) }}
<div class="form_row">
{{ form_errors(form.town) }}
{{ form_label(form.town, 'Postal code:*') }}
{{ form_widget(form.town, {'attr': { 'class': 'form_pcNum', 'maxlength': '4', 'size': '4' } } ) }}
</div>
<div class="form_row">
<!-- some more fields here -->
</div>
<div class="form_row">
<button name="btn_add" id="do_add" type="submit" class="" value="btn_add" title="Ok!">Ok</button>
</div>
{{ form_rest(form) }}
</form>
Any help is appreciated...
If you know of a relevant (working) example, that would also be great. Cheers!

Answer 1

I had similar problem with foreign key violation and I solved. Please read Symfony2 form and Doctrine2 - update foreign key in assigned entities fails [solved]