Symfony3，如何在表单中加载外部选择列表 - Symfony3, how to load an external choice list in a form?

Symfony3, how to load an external choice list in a form?

我不知道我是面临错误还是做错了什么。我正试图从自定义类加载ChoiceType表单的选项，但我得到了以下错误：

Catchable Fatal Error: Argument 1 passed to Symfony'Component'Form'ChoiceList'LazyChoiceList::__construct() must be an instance of Symfony'Component'Form'ChoiceList'Loader'ChoiceLoaderInterface, none given

我的自定义类：

<?php
namespace AppBundle'Form'ChoiceLists;
use Symfony'Component'Form'ChoiceList'SimpleChoiceList;
use Symfony'Component'Form'ChoiceList'LazyChoiceList;
class DepartmentsChoiceList extends LazyChoiceList
{
    public function loadChoiceList()
    {
         $choices = array(
             '01' => "Ain",
             '02' => "Aisne",
             '03' => "Allier",
             '04' => "Alpes de Haute Provence",
             '05' => "Alpes (Hautes)",
             //....
             '94' => "Val de Marne",
             '95' => "Val d&acute;Oise",
             '98' => "Mayotte",
             '9A' => "Guadeloupe",
             '9B' => "Guyane",
             '9C' => "Martinique",
             '9D' => "R&eacute;union",
             );
         return new SimpleChoiceList($choices);
    }
}

在我的表格中类型：

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder
        ->add('birthDepartment', ChoiceType::class, array(
            'label' => 'Département :',
            'required' => false,
            'choices' => new DepartmentsChoiceList(),
         )
     );

我发现这个功能的文档很少。

以下是我在Symfony 5.4上的过程。这可能不是最好的方法，但这是我发现的唯一有效的方法。

<?php
namespace App'Form;
use App'Controller'ApiController;
use Symfony'Component'Form'ChoiceList'Loader'ChoiceLoaderInterface;
use Symfony'Component'Form'ChoiceList'ArrayChoiceList;
class DepartmentChoiceList implements ChoiceLoaderInterface
{
    public function loadChoiceList($value = null)
    {
        $choices = array(
            '01' => "Ain",
            '02' => "Aisne",
            '03' => "Allier",
            '04' => "Alpes de Haute Provence",
            '05' => "Alpes (Hautes)",
            //....
            '94' => "Val de Marne",
            '95' => "Val d&acute;Oise",
            '98' => "Mayotte",
            '9A' => "Guadeloupe",
            '9B' => "Guyane",
            '9C' => "Martinique",
            '9D' => "R&eacute;union",
        );
        return new ArrayChoiceList($choices);
    }

    public function loadChoicesForValues(array $values, $value = null)
    {
        $result = [];
        return $result;
    }
    public function loadValuesForChoices(array $choices, $value = null)
    {
        $result = [];
        return $result;
    }
}

和formType

public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $builder
            ->add('department', ChoiceType::class, [
                'label' => 'Department',
                'choice_loader' => new DepartmentChoiceList(),
                'constraints' => [
                    new NotBlank(),
                ],
            ])
            ->add('save', SubmitType::class)
        ;
    }