Symfony 2 Embedded Form Collection Many to Many - php

Question

I have 2 Entities - User and Group. They have a many-to-many relationship and Group is used to store a users' roles.
I'm trying to make a User edit form by adding a collection, I want to be able to add a new role by selecting it from a dropdown (limited to what's already in the DB)
UserType.php:
class UserType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('username')
->add('email')
->add('forename')
->add('surname')
->add('isActive')
->add('joinDate', 'date', array('input' => 'datetime', 'format' => 'dd-MM-yyyy'))
->add('lastActive', 'date', array('input' => 'datetime', 'format' => 'dd-MM-yyyy'))
->add('groups', 'collection', array(
'type' => new GroupType(),
'allow_add' => true,
))
;
}
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'Sfox\CoreBundle\Entity\User'
));
}
}
and GroupType.php:
class GroupType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('name')
->add('role');
}
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
"data_class" => 'Sfox\CoreBundle\Entity\Group'
));
}
}
This displays the roles in the form in basic text boxes, but if I add an entry to the form, it will cascade persist a new entry into Groups and if I were to edit an entry, it would change the underlying Group data.
I tried making a GroupSelectType.php:
class GroupSelectType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('role', 'entity', array('class'=>'SfoxCoreBundle:Group', 'property'=>'name'));
}
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
"data_class" => 'Sfox\CoreBundle\Entity\Group'
));
}
}
Adding the field as an "entity" type, this displays the correct select box (but with the default values) I cant seem to bind it to the UserType form!
All I want the form to do is modify the underlying 'groups' ArrayCollection in the User entity.
Does anyone know how I can achieve this?

Answer 1

Well I worked out a solution for anyone else struggling with similar problems...
I had to create a custom form type and declare it as a service so I could pass in the Entity Manager. I then needed to make a dataTransformer to change my group objects into an integer for the form
Custom GroupSelectType:
class GroupSelectType extends AbstractType
{
/**
* #var ObjectManager
*/
private $om;
private $choices;
/**
* #param ObjectManager $om
*/
public function __construct(ObjectManager $om)
{
$this->om = $om;
// Build our choices array from the database
$groups = $om->getRepository('SfoxCoreBundle:Group')->findAll();
foreach ($groups as $group)
{
// choices[key] = label
$this->choices[$group->getId()] = $group->getName() . " [". $group->getRole() ."]";
}
}
public function buildForm(FormBuilderInterface $builder, array $options)
{
$transformer = new GroupToNumberTransformer($this->om);
$builder->addModelTransformer($transformer);
}
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
"choices" => $this->choices,
));
}
public function getParent()
{
return 'choice';
}
public function getName()
{
return 'group_select';
}
}
In the constructor I'm getting all available groups and putting them into a "choices" array which is passed to the select box as an option.
You'll also notice I'm using a custom data transformer, this is to change the groupId (which is used in the rendering of the form) to a Group entity. I made the GroupSelectType a service as well and passed in the [#doctrine.orm.entity_manager]
services.yml (bundle config):
services:
sfox_core.type.group_select:
class: Sfox\CoreBundle\Form\Type\GroupSelectType
arguments: [#doctrine.orm.entity_manager]
tags:
- { name: form.type, alias: group_select }
GroupToNumberTranformer.php
class GroupToNumberTransformer implements DataTransformerInterface
{
/**
* #var ObjectManager
*/
private $om;
/**
* #param ObjectManager $om
*/
public function __construct(ObjectManager $om)
{
$this->om = $om;
}
/**
* Transforms an object (group) to a string (number).
*
* #param Group|null $group
* #return string
*/
public function transform($group)
{
if (null === $group) {
return "";
}
return $group->getId();
}
/**
* Transforms a string (number) to an object (group).
*
* #param string $number
* #return Group|null
* #throws TransformationFailedException if object (group) is not found.
*/
public function reverseTransform($number)
{
if (!$number) {
return null;
}
$group = $this->om
->getRepository('SfoxCoreBundle:Group')
->findOneBy(array('id' => $number))
;
if (null === $group) {
throw new TransformationFailedException(sprintf(
'Group with ID "%s" does not exist!',
$number
));
}
return $group;
}
}
And my modified UserType.php - Notice I'm using my custom form type "group_select" now as it's running as a service:
class UserType extends AbstractType
{
private $entityManager;
public function __construct($entityManager)
{
$this->entityManager = $entityManager;
}
public function buildForm(FormBuilderInterface $builder, array $options)
{
$transformer = new GroupToNumberTransformer($this->entityManager);
$builder
->add('username')
->add('email')
->add('forename')
->add('surname')
->add('isActive')
->add('joinDate', 'date', array('input' => 'datetime', 'format' => 'dd-MM-yyyy'))
->add('lastActive', 'date', array('input' => 'datetime', 'format' => 'dd-MM-yyyy'));
$builder
->add(
$builder->create('groups', 'collection', array(
'type' => 'group_select',
'allow_add' => true,
'options' => array(
'multiple' => false,
'expanded' => false,
)
))
);
}
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'Sfox\CoreBundle\Entity\User'
));
}
public function getName()
{
return 'sfox_corebundle_usertype';
}
}