如何在 Symfony 3 的表单集合中将迭代特定变量传递给表单生成器？

Question

我有一个包含不同问题（项目）的评估，每个项目都有特定数量的可能选择。

我需要传递选项的数量和每个问题的标签来为每个项目（问题）构建表单。

我可以将变量从“父”表单传递到表单集合，但我不知道如何在评估“答案”属性中传递特定于每次迭代的变量。

在我的控制器中：

$evaluation = new Evaluation();
$answers = array();
// i set each answer to default 0, for the form to place them in view
foreach ($items as $index => $item) {
    $answers[$index] = array('value' => 0, 'item_id' => $item->getId());
}
$evaluation->setAnswers($answers);

$formBuilder = $this->createFormBuilder($evaluation);

$formBuilder->add("answers", CollectionType::class, array(
    'entry_type' => AnswerType::class,
    //here i pass all the items objects array to the AnswerType form.
    'entry_options' => array(
        'items' => $items,
    ),
    'allow_delete' => false,
    'allow_add' => false,
));

比在 AnswerType 表单类中：

class AnswerType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $choices = array();

        // here I have all the items available in $options['items'];
        // but each item has a specific number of choices, and I need the current one that is being built
        // and I also need other info form the item like the question it self

        for($i = 1; $i <= $current_item_number_of_choices_that_i_dont_have;$i++){
            $choices[$i] = $i;
        }

        $builder->add('value', ChoiceType::class, array(
            'choices_as_values' => true,
            'multiple'=>false,
            'expanded'=>true,
            'choices' => $choices,
            'label' => $current_item_text_label_that_I_also_need
        ));

    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'items' => null
        ));
    }
}

谢谢！ :)

Answer 1

CollectionType 可能不是您现在需要的类型来实现它，因为它隐藏了您需要处理的层（当前项）。所以最好自己添加答案集合。像这样的：

class AnswerCollectionType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        foreach ($options['items'] as $index => $item) {
            $builder->add($index + 1, AnswerType::class, [
                'item' => $item,
            ]);
        }
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setRequired('items');
    }
}

class AnswerType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $item = $options['item'];

        $choices = [];
        for ($i = 1; $i <= $item->getNumChoices(); $i++) {
            $choices[$i] = $i;
        }

        $builder->add('value', ChoiceType::class, [
            'label' => $item->getLabel(),
            'choices' => $choices,
            'expanded' => true,
        ]);
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setRequired('item');
    }
}

请注意，AnswerType 现在需要 item 选项才能正确构建当前选择表单。

$formBuilder->add('answers', AnswerCollectionType::class, [
    'items' => $items,
])

---

另一方面，CollectionType 的解决方法更复杂（通过使用事件）需要静态内部计数器来了解当前项目。

详情请见http://symfony.com/doc/current/form/dynamic_form_modification.html。