Question

我正在尝试将一个城市添加到从FOSUserBundle扩展BaseUser的User类，我正在按照此页面中的指南操作： http://symfony.com/doc/current/form/dynamic_form_modification.html#form-events-submitted-data

我已经创建了一个RegistrationType类，其代码如下：

public function buildForm(FormBuilderInterface $builder, array $options)
{
    /* i setted a name field just to check that this form builder is used then i try to create a user */
    $builder->add('name');
    $builder->add('provincia', EntityType::class, array(
            'class'         => 'AppBundle\Entity\State',
            'placeholder'   => '', #
        ));

    $builder->addEventListener(
        FormEvents::PRE_SET_DATA,
        function (FormEvent $event) {
            $form = $event->getForm();

            $data = $event->getData();

            $state = $data->getState();
            $cities = null === $state ? array() : $state->getCities();

            $form->add('city', EntityType::class, array(
                'class'       => 'AppBundle\Entity\City',
                'placeholder' => '',
                'choices'     => $cities,
            ));
        }
    );
//...
}

问题是当它在$ data-＆gt; getState（）中抛出错误时，它告诉我“错误：在null上调用成员函数getState（）”。可能会发生什么？

Answer 1

class RegistrationType extends AbstractType
{
   public function buildForm(FormBuilderInterface $builder, array $options)
   {
      $builder->add('name');
      $builder->add('state', EntityType::class, array(
            'class'         => 'AppBundle\Entity\State',
            'mapped'        => false,
            'placeholder'   => '', #
        ));

        $formModifier = function (FormInterface $form, State $state= null) {
            $cities = null === $state? array() : $state->getCities();

            $form->add('city', EntityType::class, array(
                'class'       => 'AppBundle\Entity\City',
                'placeholder' => '-Choose a state-',
                'choices'     => $cities,
            ));
        };

        $builder->addEventListener(
            FormEvents::PRE_SET_DATA,
            function (FormEvent $event) use ($formModifier) {
                $data = $event->getData();

                if($data === null || !method_exists($data, 'getState')) {
                    $formModifier($event->getForm(), null);
                } else {
                    $formModifier($event->getForm(), $data->getProvincia());

                }
            }
        );

        $builder->get('state')->addEventListener(
            FormEvents::POST_SUBMIT,
            function (FormEvent $event) use ($formModifier) {
                // It's important here to fetch $event->getForm()->getData(), as
                // $event->getData() will get you the client data (that is, the ID)
                $state = $event->getForm()->getData();

                // since we've added the listener to the child, we'll have to pass on
                // the parent to the callback functions!
                $formModifier($event->getForm()->getParent(), $provincia);
            }
        );
    }

    public function getParent()
    {
        return 'FOS\UserBundle\Form\Type\RegistrationFormType';
    }

    public function getBlockPrefix()
    {
        return 'app_user_registration';
    }

    public function getName()
    {
        return $this->getBlockPrefix();
    }
}

真正让我发疯的是$ event-＆gt; getData（），根据官方doc示例带来的东西，在我的情况下是空的。我已经成功地解决了这个注册表格的问题，但现在我在配置文件编辑表格中遇到了同样的问题argggghhhhh

提交表单的动态生成：$ event-＆gt; getData（）返回null

1 个答案: