Update Form with 'choice_list' to Symfony >= 2.8 - php

Question

I want to update a form class to Symfony2.8 (and later to Symfony3). Now the form is converted except one attribute, the choice_list, that is not supported anymore. And I don't know how to do this.
I have the following form type that is defined also as a service:
class ExampleType extends AbstractType
{
/** #var Delegate */
private $delegate;
public function __construct(Delegate $delegate)
{
$this->delegate = $delegate;
}
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->add('list', ChoiceType::class, array(
'choice_list' => new ExampleChoiceList($this->delegate),
'required'=>false)
);
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'ExampleClass',
));
}
}
And I have the following class for the choice list:
class ExampleChoiceList extends LazyChoiceList
{
/** #var Delegate */
private $delegate;
public function __construct(Delegate $delegate)
{
$this->delegate = $delegate;
}
/**
* Loads the choice list
* Should be implemented by child classes.
*
* #return ChoiceListInterface The loaded choice list
*/
protected function loadChoiceList()
{
$persons = $this->delegate->getAllPersonsFromDatabase();
$personsList = array();
foreach ($persons as $person) {
$id = $person->getId();
$personsList[$id] = (string) $person->getLastname().', '.$person->getFirstname();
}
return new ArrayChoiceList($personsList);
}
}
The class ExampleChoiceList generate the choice list how I want to have it, and until now it worked. But the attribute choice_list is not supported anymore, and my question is "how do I get this converted without too much work?". I read that I should use simple choice but how I get that what I want (the specific label from the database) in Symfony 2.8. I hope somebody can help me.

Answer 1

By using a ChoiceListInterface you are almost there.
I suggest you change the ExampleChoiceList to implement the Symfony\Component\Form\ChoiceList\Loader\ChoiceLoaderInterface instead, it requires you implement 3 methods:
<?php
// src/AppBundle/Form/ChoiceList/Loader/ExampleChoiceLoader.php
namespace AppBundle\Form\ChoiceList\Loader;
use Acme\SomeBundle\Delegate;
use Symfony\Component\Form\ArrayChoiceList;
use Symfony\Component\Form\Loader\ChoiceLoaderInterface;
class ExampleChoiceLoader implements ChoiceLoaderInterface
{
/** $var ArrayChoiceList */
private $choiceList;
/** #var Delegate */
private $delegate;
public function __construct(Delegate $delegate)
{
$this->delegate = $delegate;
}
/**
* Loads the choice list
*
* $value is a callable set by "choice_name" option
*
* #return ArrayChoiceList The loaded choice list
*/
public function loadChoiceList($value = null)
{
if (null !== $this->choiceList) {
return $this->choiceList;
}
$persons = $this->delegate->getAllPersonsFromDatabase();
$personsList = array();
foreach ($persons as $person) {
$label = (string) $person->getLastname().', '.$person->getFirstname();
$personsList[$label] = (string) $person->getId();
// So $label will be displayed and the id will be used as data
// "value" will be ids as strings and used for post
// this is just a suggestion though
}
return $this->choiceList = new ArrayChoiceList($personsList);
}
/**
* {#inheritdoc}
*
* $choices are entities or the underlying data you use in the field
*/
public function loadValuesForChoices(array $choices, $value = null)
{
// optimize when no data is preset
if (empty($choices)) {
return array();
}
$values = array();
foreach ($choices as $person) {
$values[] = (string) $person->getId();
}
return $values;
}
/**
* {#inheritdoc}
*
* $values are the submitted string ids
*
*/
public function loadChoicesForValues(array $values, $value)
{
// optimize when nothing is submitted
if (empty($values)) {
return array();
}
// get the entities from ids and return whatever data you need.
// e.g return $this->delegate->getPersonsByIds($values);
}
}
register both the loader and the type as services so they are injected:
# app/config/services.yml
services:
# ...
app.delegate:
class: Acme\SomeBundle\Delegate
app.form.choice_loader.example:
class: AppBundle\Form\ChoiceList\Loader\ExampleChoiceLoader
arguments: ["#app.delegate"]
app.form.type.example:
class: AppBundle\Form\Type\ExampleType
arguments: ["#app.form.choice_loader.example"]
Then change the form type to use the loader:
<?php
// src/AppBundle/Form/Type/ExampleType.php
namespace AppBundle\Form\Type;
use AppBundle\Form\ChoiceList\Loader\ExampleChoiceLoader;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
class ExampleType extends AbstractType
{
/** #var ExampleChoiceLoader */
private $loader;
public function __construct(ExampleChoiceLoader $loader)
{
$this->loader = $loader;
}
public function buildForm(FormBuilderInterface $builder, array $options = array())
{
$builder->add('list', ChoiceType::class, array(
'choice_loader' => $this->loader,
'required' => false,
));
}
// ...
}

Answer 2

Yes, 'choice_list' is deprecated with SYmfony 2.8, but you can use 'choices' instead, which accepts an array as well. From documentation:
The choices option is an array, where the array key is the item's
label and the array value is the item's value.
You must just pay attention than in Symfony 3.0, keys and values are inversed, and in Symfony 2.8, the recommended way is to use the new inversed order, and to specify 'choices_as_values' => true.
So, in the form type:
$builder->add('list', ChoiceType::class, array(
'choices' => new ExampleChoiceList($this->delegate),
'choices_as_values' => true,
'required'=>false));
And in ExampleChoiceList:
protected function loadChoiceList()
{
$persons = $this->delegate->getAllPersonsFromDatabase();
$personsList = array();
foreach ($persons as $person) {
$id = $person->getId();
$personsList[(string) $person->getLastname().', '.$person->getFirstname()] = $id; // <== here
}
return new ArrayChoiceList($personsList);
}
UPDATE:
Ok, so I suggest you don't use a ChoiceType at all, but a EntityType, as you seem to fetch all "Persons" from database. And to display "Last Name, First Name" as a label, use the 'choice_label' option. Assuming your entity is called 'Person':
$builder->add('list', EntityType::class, array(
'class' => 'AppBundle:Person',
'choice_label' => function ($person) {
return $person->getLastName() . ', ' . $person->getFirstName();
}
));