Doctrine ArrayCollection Call to a member function setValue() on null - php

Question

I'm writing an application using Zend Framework 3. To manage database I decided to use Doctrine. I have two tables pages and pages_meta(something based on wordpress db). They are realted to each other in one-to-many, many-to-one relation. In pages_meta I have key page_id. Now when I try to get meta form Page Entity I got following error:
File: /home/platne/serwer18346/vendor/doctrine/orm/lib/Doctrine/ORM/PersistentCollection.php:169
Message: Call to a member function setValue() on null
Now the application code:
Page Entity(removed some code to show important part):
namespace Core\Model;
use DateTime;
use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\ORM\Mapping as ORM;
/**
* Class Page
* #package Core\Model
* #ORM\Entity
* #ORM\Table(name="pages")
*/
class Page
{
/**
* #var int
* #ORM\Id
* #ORM\GeneratedValue
* #ORM\Column(name="id")
*/
protected $id;
//other fields definition(here is slug to found by)
/**
* #var ArrayCollection
* #ORM\OneToMany(targetEntity="\Core\Model\PageMeta", mappedBy="pages")
* #ORM\JoinColumn(name="id", referencedColumnName="page_id")
*/
protected $meta;
/**
* Page constructor.
*/
public function __construct()
{
$this->meta = new ArrayCollection();
}
/**
* #return int
*
*/
public function getId()
{
return $this->id;
}
/**
* #param mixed $key
* #return ArrayCollection
*/
public function getPageMeta($key = null){
if(!$key) return $this->meta;
return $this->meta->current(); //this is causing the problem tried other functions as well
}
}
PageMeta Entity(same here I removed some code):
namespace Core\Model;
use Doctrine\ORM\Mapping as ORM;
/**
* Class PageMeta
* #package Core\Model
* #ORM\Entity
* #ORM\Table(name="page_meta")
*/
class PageMeta
{
/**
* #var int
* #ORM\Id
* #ORM\GeneratedValue
* #ORM\Column(name="id")
*/
protected $id;
/**
* #var int
* #ORM\Column(type="integer", name="page_id")
*/
protected $page_id;
/**
* #var Page
* #ORM\ManyToOne(targetEntity="\Core\Model\Page", inversedBy="page_meta")
* #ORM\JoinColumn(name="page_id", referencedColumnName="id")
*/
protected $page;
/**
* #return int
*/
public function getId(): int
{
return $this->id;
}
/**
* #return int
*/
public function getPageId(): int
{
return $this->page_id;
}
/**
* #param int $page_id
* #return PageMeta
*/
public function setPageId(int $page_id): PageMeta
{
$this->page_id = $page_id;
return $this;
}
//other field definition
/**
* #return Page
*/
public function getPage(){ //this works fine
return $this->page;
}
}
In the controller:
$this->getEntityManager()->getRepository(Page::class);
$page = $pagesTable->findOneBySlug($slug);
//check if page exists
$page->getPageMeta('test'); //this line cause the problem.
Full stack error you can see on page: http://bibliotekadomowa.pl/o-nas

Answer 1

I think it may be an issue with the "mappedBy" param in Page, try changing that to
mappedBy="page"
As it should match the variable name not the table name