添加一个模型转换器，以嵌入形式转换多个字段

Question

我正在尝试\DateInterval从2个输入字段中读取a ，如下所示：public function buildForm(FormBuilderInterface $builder, array $options){    $builder        ->add('name', TextType::class, ['label' => "Name"])        ->add('duration', DateIntervalType::class, ['label' => false])    ;}public function configureOptions(OptionsResolver $resolver){    $resolver->setDefaults(['data_class' => NamedInterval::class]);}这是我的DateIntervalType::buildForm：public function buildForm(FormBuilderInterface $builder, array $options){    $builder        ->add('amount', IntegerType::class)        ->add('kind', ChoiceType::class, ['choices' => ['Year' => 'Y', 'Month' => 'M', 'Week' => 'W']])    ;}这是我尝试过的变压器：$builder->get('duration')->addModelTransformer(new CallbackTransformer(    function ($property) {        return new \DateInterval('P' . $property['amount'] . $property['kind']);    },    function ($property) {        /* compute $specString from $property assuming it's a \DateInterval */        /* ... */        return ['amount' => 1, 'kind' => 'W'];    }));因此，这是行不通的，我$property总是null在从表单数据转换到表单数据后验证表单，\DateInterval而我甚至不确定我是否曾经使用过从变压器转换\DateInterval成表单数据，我在做什么错呢？

Answer 1

看来CallbackTransformer是相反的：

$builder->get('duration')->addModelTransformer(new CallbackTransformer(

    function ($property) {

        /* compute specString from $property assuming it's a \DateInterval */

        /* ... */

        return ['amount' => 1, 'kind' => 'W'];

    },

    function ($property) {

        if (!$property) return null;

        return new \DateInterval('P' . $property['amount'] . $property['kind']);

    }

));

现在它就像一种魅力！

编辑：\DateInterval将几周转换为几天，'Day' => 'D'在选项列表中也应该有一个选项。