How to correctly render a form? - php

Question

Symfony makes it all so easy. It sets out the big lines for your project and nothing ever goes wrong. Until something does go wrong. You'll be looking for the right solution for days. At least that's what I'm doing right now.
I'm working on a little test project in which you can add urls as bookmarks and give each url a variety of tags to categorize the urls.
I have used the generate:doctrine:crud command to build my forms. But I am getting a weird error.
An exception has been thrown during the rendering of a template ("Catchable Fatal Error: Object of class Bla\LinkBundle\Entity\Url could not be converted to string") in form_div_layout.html.twig at line 13.
I can solve this issue by adding a __toString() method in my Url entity but I wanna know why.
The problem is with the name property being null. If I return this value as '' using __toString() it works fine. But I do not like this solution. All other values are null as well when I am in the "create url" form, so why is it complaining about the name property?
Form
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('name')
->add('url')
->add('flags')
->add('tags', EntityType::class, array(
'class' => 'Bla\LinkBundle\Entity\Tag',
'choice_label' => 'name',
'multiple' => true,
))
;
}
Controller
public function newAction(Request $request)
{
$url = new Url();
$form = $this->createForm('Bla\LinkBundle\Form\UrlType', $url);
$form->handleRequest($request);
if ($form->isSubmitted() && $form->isValid()) {
$em = $this->getDoctrine()->getManager();
$em->persist($url);
$em->flush();
return $this->redirectToRoute('url_show', array('id' => $url->getId()));
}
return $this->render('url/new.html.twig', array(
'url' => $url,
'form' => $form->createView(),
));
}
Entity
namespace Bla\LinkBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
use Doctrine\Common\Collections\ArrayCollection;
use Bla\LinkBundle\Entity\Tag;
/**
* URL
*
* #ORM\Table(name="urls")
* #ORM\Entity
*/
class Url
{
/**
* #var string
*
* #ORM\Column(name="name", type="string", length=255, nullable=false)
*/
private $name;
/**
* #var string
*
* #ORM\Column(name="url", type="text", length=65535, nullable=false)
*/
private $url;
/**
* #var integer
*
* #ORM\Column(name="flags", type="integer", nullable=false)
*/
private $flags;
/**
* #var integer
*
* #ORM\Column(name="id", type="bigint")
* #ORM\Id
* #ORM\GeneratedValue(strategy="IDENTITY")
*/
private $id;
/**
* #ORM\ManyToMany(targetEntity="\Bla\LinkBundle\Entity\Tag", cascade={"persist"})
* #ORM\JoinTable(name="url_tag",
* joinColumns={#ORM\JoinColumn(name="url_id", referencedColumnName="id")},
* inverseJoinColumns={#ORM\JoinColumn(name="tag_id", referencedColumnName="id", unique=true)}
* )
*/
protected $tags;
public function __construct()
{
$this->tags = new ArrayCollection();
}
/**
* Set name
*
* #param string $name
*
* #return Urls
*/
public function setName($name)
{
$this->name = $name;
return $this;
}
/**
* Get name
*
* #return string
*/
public function getName()
{
return $this->name;
}
/**
* Set url
*
* #param string $url
*
* #return Urls
*/
public function setUrl($url)
{
$this->url = $url;
return $this;
}
/**
* Get url
*
* #return string
*/
public function getUrl()
{
return $this->url;
}
/**
* Set flags
*
* #param integer $flags
*
* #return Urls
*/
public function setFlags($flags)
{
$this->flags = $flags;
return $this;
}
/**
* Get flags
*
* #return integer
*/
public function getFlags()
{
return $this->flags;
}
/**
* Get id
*
* #return integer
*/
public function getId()
{
return $this->id;
}
/**
* #param \Doctrine\Common\Collections\ArrayCollection $tags
* #return Urls
*/
public function setTags($tags)
{
$this->tags = $tags;
return $this;
}
/**
* #return \Doctrine\Common\Collections\ArrayCollection
*/
public function getTags()
{
return $this->tags;
}
/**
* Add tag
*
* #param Tag $tag
* #return Urls
*/
public function addTag(Tag $tag)
{
$this->tags->add($tag);
return $this;
}
/**
* Remove tag
*
* #param Tags $tag
*/
public function removeTag(Tag $tag)
{
$this->tags->removeElement($tag);
}
}

Answer 1

try to implements this into form class :
public function getName()
{
return 'filter_type_url';
}
public function getParent()
{
return 'multiselectentity';
}