Override One To Many Template for Collection using Doctrine `indexBy` in Sonata Admin Forms

_settings.html.twig

LOC_ID = {{ form.children.4.value.vars['value'] }} {# index exists #}
LOC_ID = {{ form.children.LOC_ID.value.vars['value'] }} {# index does not exist #}

admin.yml

services:
    sonata.user.admin.user:
        class: Application\Sonata\UserBundle\Admin\UserAdmin
        tags:
            - { name: sonata.admin, manager_type: orm, group: "%sonata.user.admin.groupname%", label_catalogue: "messages", label: "Benutzer"}
        arguments:
            - ~
            - Application\Sonata\UserBundle\Entity\User
            - ~    
        calls:
            - [ addChild, [ @sonata.user.admin.user_setting ] ]            
    sonata.user.admin.user_setting:
        class: Application\Sonata\UserBundle\Admin\UserSettingAdmin
        tags:
            - { name: sonata.admin, manager_type: orm, group: "%sonata.user.admin.groupname%", label_catalogue: "messages", label: "Konfiguration"}
        arguments:
            - ~
            - Application\Sonata\UserBundle\Entity\UserSetting
            - ~    

form_admin_fields.html.twig

{#{% use 'SonataAdminBundle:Form:form_admin_fields.html.twig' %}#}
 
{% block sonata_admin_orm_one_to_many_widget %}

{% if sonata_admin.name == 'settings' %}
    {% include 'ApplicationSonataUserBundle:UserAdmin:_settings.html.twig' %}
{%  else %}
    {% include 'SonataDoctrineORMAdminBundle:CRUD:edit_orm_one_to_many.html.twig' %}
{% endif %}
 
{% endblock %}

settings.sql

SELECT 
  t0.id AS id1, 
  t0.config_key AS config_key2, 
  t0.config_value AS config_value3, 
  t0.datetime AS datetime4, 
  t0.users_id AS users_id5 
FROM 
  users_config t0 
WHERE 
  t0.users_id = ?

User.php

<?php

namespace Application\Sonata\UserBundle\Entity;

use Sonata\UserBundle\Entity\BaseUser as BaseUser;
//use FOS\UserBundle\Model\User as BaseUser;
//use Doctrine\Common\Collections\Collection;
use Gedmo\Mapping\Annotation as Gedmo;
use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;

use Doctrine\ORM\Mapping as ORM;

/**
 * User
 *
 * @ORM\Entity(repositoryClass="UserRepository")
 * @ORM\Table(name="users", indexes={
 *  @ORM\Index(columns={"username"}),
 *  @ORM\Index(columns={"users_key"}),
 *  @ORM\Index(columns={"block_user"}),
 *  @ORM\Index(columns={"deleted"})
 * })
 * UniqueEntity(fields="email", message="Ce nom d'utilisateur est déjà pris.", groups={"registration"})
 * UniqueEntity(fields="email_canonical", message="Ce nom d'utilisateur est déjà pris.", groups={"registration"})
 * @UniqueEntity(fields="email", message="Ce nom d'utilisateur est déjà pris.")
 * @UniqueEntity(fields="email_canonical", message="Ce nom d'utilisateur est déjà pris2.")
 * ORM\AttributeOverrides({
 *      ORM\AttributeOverride(name="email", column=@ORM\Column(type="string", name="email", length=255, unique=false, nullable=true)),
 *      ORM\AttributeOverride(name="emailCanonical", column=@ORM\Column(type="string", name="email_canonical", length=255, unique=false, nullable=true))
 * })
 */
class User extends BaseUser
{
    /**
     * @var integer $id
     *
     * @ORM\Column(name="users_id", type="integer", precision=0, scale=0, nullable=false, unique=false)
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="IDENTITY")
     */
    protected $id;

    /**
     * @var Collection $settings
     *
     * @ORM\OneToMany(targetEntity="Application\Sonata\UserBundle\Entity\UserSetting", indexBy="config_key", mappedBy="user", fetch="EAGER")
     * ORM\OneToMany(targetEntity="Application\Sonata\UserBundle\Entity\UserSetting", indexBy="config_key", mappedBy="user")
     */
    protected $settings;

    public function __construct() {
        parent::__construct();
        $this->settings = new \Doctrine\Common\Collections\ArrayCollection();
    }

    public function getSettings()
    {
        return $this->settings;
    }
}

user.sql

SELECT 
  t0.username AS username1, 
  t0.username_canonical AS username_canonical2, 
  t0.email AS email3, 
  t0.email_canonical AS email_canonical4, 
  t0.enabled AS enabled5, 
  t0.salt AS salt6, 
  t0.password AS password7, 
  t0.last_login AS last_login8, 
  t0.locked AS locked9, 
  t0.expired AS expired10, 
  t0.expires_at AS expires_at11, 
  t0.confirmation_token AS confirmation_token12, 
  t0.password_requested_at AS password_requested_at13, 
  t0.roles AS roles14, 
  t0.credentials_expired AS credentials_expired15, 
  t0.credentials_expire_at AS credentials_expire_at16, 
  t0.created_at AS created_at17, 
  t0.updated_at AS updated_at18, 
  t0.date_of_birth AS date_of_birth19, 
  t0.firstname AS firstname20, 
  t0.lastname AS lastname21, 
  t0.website AS website22, 
  t0.biography AS biography23, 
  t0.gender AS gender24, 
  t0.locale AS locale25, 
  t0.timezone AS timezone26, 
  t0.phone AS phone27, 
  t0.facebook_uid AS facebook_uid28, 
  t0.facebook_name AS facebook_name29, 
  t0.facebook_data AS facebook_data30, 
  t0.twitter_uid AS twitter_uid31, 
  t0.twitter_name AS twitter_name32, 
  t0.twitter_data AS twitter_data33, 
  t0.gplus_uid AS gplus_uid34, 
  t0.gplus_name AS gplus_name35, 
  t0.gplus_data AS gplus_data36, 
  t0.token AS token37, 
  t0.two_step_code AS two_step_code38, 
  t0.users_id AS users_id39, 
  t0.users_name AS users_name40, 
  t0.users_email_address AS users_email_address41, 
  t0.users_website AS users_website42, 
  t0.users_level AS users_level43, 
  t0.users_key AS users_key44, 
  t0.block_user AS block_user45, 
  t0.session_id AS session_id46, 
  t0.note AS note47, 
  t0.role AS role48, 
  t0.deleted AS deleted49 
FROM 
  users t0 
WHERE 
  t0.users_id = ?

UserAdmin.php

<?php

namespace Application\Sonata\UserBundle\Admin;

use Sonata\UserBundle\Admin\Model\UserAdmin as SonataUserAdmin;
use Sonata\AdminBundle\Route\RouteCollection;
use Sonata\AdminBundle\Admin\AdminInterface;
use Sonata\AdminBundle\Datagrid\ListMapper;
use Sonata\AdminBundle\Datagrid\DatagridMapper;
use Sonata\AdminBundle\Form\FormMapper;

use Knp\Menu\ItemInterface as MenuItemInterface;

use Application\Sonata\UserBundle\Entity\UserSetting;

class UserAdmin extends SonataUserAdmin
{

    protected $maxPerPage = 10;

    protected $userManager;

    public function getUserManager()
    {
        if (!$this->userManager) {
            $this->userManager = $this->configurationPool->getContainer()->get('fos_user.user_manager');

        }

        return $this->userManager;
    }

    protected function configureRoutes(RouteCollection $collection)
    {
        $collection
            ->remove('delete')
            ->remove('export')
        ;
    }

    public function getFormTheme()
    {
        return array_merge(
            parent::getFormTheme(),
            array('ApplicationSonataUserBundle:UserAdmin:form_admin_fields.html.twig')
        );
    }

    protected function configureFormFields(FormMapper $formMapper)
    {
        $subject = $this->getSubject();

        $formMapper
            ->with('General')
                ->add('gender', 'sonata_user_gender', array(
                    'required' => true,
                    'translation_domain' => $this->getTranslationDomain()
                ))
                ->add('firstname', null, array('required' => false))
                ->add('lastname', null, array('required' => false))
                ->add('email', null, array('required' => false))
                ->add('website', null, array('required' => false))
            ->end()
        ;

//        if ($this->getSubject() && !$this->getSubject()->hasRole('ROLE_SUPER_ADMIN')) {
        if ($this->getSubject() && !$this->getSubject()->hasRole('ROLE_ADMIN')) {
            $formMapper
                ->with('Zugang')
                    ->add('username')
                    ->add('plainPassword', 'text', array(
                        'required' => (!$this->getSubject() || is_null($this->getSubject()->getId()))
                    ))
                    ->add('realRoles', 'sonata_security_roles', array(
//                    ->add('roles', 'sonata_security_roles', array(
                        'label'    => 'form.label_roles',
                        'expanded' => true, // render checkboxes instead of select
                        'multiple' => true,
                        'required' => false,
                        'choices' => [
                            'ROLE_USER' => 'Partner',
                            'ROLE_ADMIN' => 'Admin',
//                            'ROLE_SUPER_ADMIN' => 'Superadmin',
                        ]
                    ))
//                    ->add('roles', 'choice', [
//                        'multiple' => true,
//                        'choices' => ['ROLE_USER' => 'user', 'ROLE_ADMIN' => 'admin']
//                    ])
                    ->add('enabled', null, array('required' => false))
                    ->add('locked', null, array('required' => false))
                    ->add('expired', null, array('required' => false))
                    ->add('credentialsExpired', null, array('required' => false))
                ->end();
        }

        $userSetting = new UserSetting();

        // @todo how to index by?
        $formMapper
            ->with('Konfiguration')
                ->add('settings', 'sonata_type_collection', array(
                    'label' => false,
//                    'btn_add' => false,
                    'type_options' => array('delete' => false)
                ), array(
                    'edit' => 'inline',
                    'inline' => 'table',
//                    'template' => 'ApplicationSonataUserBundle:UserAdmin:form_admin_fields.html',
                    'allow_delete' => false, // no effect
                    'link_parameters' => array(
                        'keys' => $userSetting->getKeys()
                    )
                ))
            ->end()
        ;
    }

    public function createQuery($context = 'list')
    {
        $query = parent::createQuery($context);

        $query->addSelect(
                'PARTIAL ' . $query->getRootAlias() . '.{id, username, email, enabled, locked, createdAt}',
                'PARTIAL g.{id, name}',
                'PARTIAL s.{id, key, value}'
            )
            ->leftJoin($query->getRootAlias() . '.groups', 'g')
            ->leftJoin($query->getRootAlias() . '.settings', 's')
        ;

        return $query;
    }
}