表单的视图数据应该是另一个类错误的实例，创建另一个实体的表单实例

I get the following error when trying to create a form from another entity to pass through to my view.

I have two entities in this context CourseGuide and CourseGuideRow and I would like to pass through a form view of CourseGuideRowType to my view - how can I do this?

The form's view data is expected to be an instance of class CRMPicco\CourseBundle\Entity\CourseGuide, but is an instance of class CRMPicco\CourseBundle\Entity\CourseGuideRow. You can avoid this error by setting the "data_class" option to null or by adding a view transformer that transforms an instance of class CRMPicco\CourseBundle\Entity\CourseGuideRow to an instance of CRMPicco\CourseBundle\Entity\CourseGuide.

This is my controller:

// CourseGuideController.php
public function viewAction(Request $request)
{
    if (!$courseId = $request->get('id')) {
        throw new NotFoundHttpException('No Course ID provided in ' . __METHOD__);
    }

    $resource = $this->get('crmpicco.repository.course_guide_row')->createNew();
    $form     = $this->getForm($resource);

    // ...

}

My Symfony FormBuilder class:

// CourseGuideRowType.php
use Sylius\Bundle\ResourceBundle\Form\Type\AbstractResourceType;
use Symfony\Component\Form\FormBuilderInterface;

class CourseGuideRowType extends AbstractResourceType
{
    /**
     * {@inheritdoc}
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('channel', 'crmpicco_channel_choice', array('data_class' => null))
            ->add('name', 'text')
            ->add('courses', 'text')
        ;
    }

    /**
     * @return string name
     */
    public function getName()
    {
        return 'crmpicco_course_guide_row';
    }
}

I have tried the data_class => null suggestion mentioned elsewhere, but this has no effect.

If I pass through the data_class like this:

$form     = $this->getForm($resource, array('data_class' => 'CRMPicco\CourseBundle\Entity\CourseGuideRow'));

I then get this:

Neither the property "translations" nor one of the methods "getTranslations()", "translations()", "isTranslations()", "hasTranslations()", "__get()" exist and have public access in class "CRMPicco\CourseBundle\Entity\CourseGuideRow".

Why is this? There are translations attached to the CourseGuide entity but not the CourseGuideRow.

try to add this function in your FormType:

public function configureOptions(OptionsResolver $resolver)
{
    $resolver->setDefaults(array(
        'data_class' => 'YourBundle\Entity\YourEntity',
    ));
}

And don't forget the specific use:

use Symfony\Component\OptionsResolver\OptionsResolver;

EDIT

In native Symfony (with the Form component):

public function showAction()
{
    /.../
    $entity = new YourEntity();
    $form = $this->createForm('name_of_your_form_type', $entity); 

    # And the response:

    return $this->render('your_template.html.twig', ['form' => $form->createView()]);
}