Sonata: Fatal error: Maximum function nesting level of '100' reached.. when embedding forms

Question

EDIT: For anyone interested on solving the same issue, that did the trick:

echo `'xdebug.max_nesting_level = 250' >> /etc/php5/conf.d/xdebug.ini` 

---

I've created 3 Admins for 3 entities linked to each other, where A Admin is embedding B Admin and B Admin embeds C Admin. B entity has a ManyToOne relation with A and B entity.

A entity embeds B entity with the following code:

$formMapper->add('b', 'sonata_type_collection', array(
    'by_reference' => false
), array(
    'edit' => 'inline',
    'inline' => 'table',
    'sortable'  => 'position'
) );

B entity embeds C entity with the following one:

 $formMapper->add( 'c', 'sonata_type_model', array( 
    'required'  => true, 
    'label'     => ucfirst( $this->trans( 'c', array(), $this->translationDomain, $this->langCode ) )
    ), array( 'edit' => 'list' ) );

Note: changing 'edit' => 'list' in favour of 'edit' => 'standard' avoids the following error.

Placing array( 'edit' => 'list' ) on B Admin entity on a sonata_type_model form type gives the following error while editing A enity. If instead array( 'edit' => 'standard' ) is used then no error is output:

Sonata: Fatal error: Maximum function nesting level of '100' reached, aborting! in myProject/vendor/doctrine-common/lib/Doctrine/Common/Lexer.php on line 756  

The tricky or curious thing is that no matter if edit is list or standard if i go to B admin to edit it. the problem only appears if i edit B embedded into A with edit list option set. And this is happening to me in some other entities where i implemented the same behaviour.

Here are A, B and C entity and how they link each other:

A entity:

class A
{
    /**
     *  @ORM\Id
     *  @ORM\Column(type="integer", length=4)
     *  @ORM\GeneratedValue(strategy="IDENTITY")
     */
    private $id;
    /** @ORM\OneToMany(targetEntity="B", mappedBy="a", cascade={"persist"}, orphanRemoval=true ) */
    protected $b;
}

B entity:

class B
{
    /**
     *  @ORM\Id
     *  @ORM\Column(type="integer", length=4)
     *  @ORM\GeneratedValue(strategy="IDENTITY")
     */
    private $id
    /**
     *  @ORM\ManyToOne(targetEntity="C", inversedBy="b", cascade={"persist"} )
     *  @ORM\JoinColumn(name="c_id", nullable=false, referencedColumnName="id", onDelete="CASCADE")
     */
    private $c;
    /**
     *  @ORM\ManyToOne(targetEntity="A", inversedBy="b", cascade={"persist"} )
     *  @ORM\JoinColumn(name="a_id", nullable=false, referencedColumnName="id", onDelete="CASCADE")
     */
    private $a;
}

C entity:

Class C
{
    /**
     *  @ORM\Id
     *  @ORM\Column(type="integer", length=4)
     *  @ORM\GeneratedValue(strategy="IDENTITY")
     */
    private $id;
    /** @ORM\OneToMany(targetEntity="B", mappedBy="c", cascade={"persist"} ) */
    private $b;
}

To be able to take a look at it all you can use sonata demo project to check for a similar behaviour.
As you can see it is the same use case which can be found on Sonata Project demo where Gallery is linked against GalleHasMedias which links against Media: http://demo.sonata-project.org/admin/sonata/media/gallery/255/edit?context=default As you can see, GalleryHasMedia has a ManyToOne relation with Gallery and another one with Media so when you edit a Gallery ou can see a sonata_type_model with edit' => 'inline','inline' => 'table', so a GalleryHasMedia is embedded inside Gallery form in order to be able to add new Medias which are going to be linked with the current Gallery and stored inside GalleryHasMedia.

Has any one faced a situation like the exposed one? Hope someone could point to the right direction or help to get a clue on what's going on.

PD: For me it seems like B and C entities are linking/embedding each other in an endless loop. But as said, 3 Admins are working great separately (while A does not embeds B).

Answer 1

For anyone interested on solving the same issue, that did the trick:

echo `'xdebug.max_nesting_level = 250' >> /etc/php5/conf.d/xdebug.ini` 

Answer 2

This is a common problem with servers running xdebug. You must increase the nesting level by increasing the xdebug.max_nesting_level in your xdebug.ini configuration. Setting it to something like 250 should suffice.

One quick way to add the setting is to do this on your linux server:

echo `'xdebug.max_nesting_level = 250' >> /etc/php5/conf.d/xdebug.ini`