Embedding a dynamically generated form into another - php

Question

I use Symfony2.1's FormBuilder to create a dynamic form in the controller:
$form = $this->createFormBuilder($defaultData);
$form->add('field','text');
I would like to embed another form in the same way and embed it with the main form.
$subForm = $this->createFormBuilder();
$subForm->add('subfield','text');
// Does not work
$form->add('subform', $subForm);
Unfortunately this setup does not work properly. I could not find any way how to add a dynamically generated subform into a dynamically generated form, like the example above.
What's the function call I am missing?
The exception thrown by the example code above is
UnexpectedTypeException: Expected argument of type "string or
Symfony\Component\Form\FormTypeInterface",
"Symfony\Component\Form\Form" given.

Answer 1

I would create two Form Clases in two separate fields:
<?php
namespace Acme\DemoBundle\Form\Type;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolverInterface;
class FirstFormType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('field', 'text')
->add('subform', new SecondFormType());
}
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'Acme\DemoBundle\Entity\FirstEntity'
));
}
public function getName()
{
return 'first';
}
}
<?php
namespace Acme\DemoBundle\Form\Type;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolverInterface;
class SecondFormType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('subfield', 'text');
}
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'Acme\DemoBundle\Entity\SecondEntity',
));
}
public function getName()
{
return 'second';
}
}
After this creation you can create your form from any Controller with this line for creation forms:
$form = $this->createForm(new FirstFormType());
or for edition forms:
$form = $this->createForm(new FirstFormType(), $first);
In your example code you are trying to assig to a field an entire form instead of a Form Type.
Hope it helps

Answer 2

Recommended symfony-way is to create separate FormType classes, as mentioned above. But if you really want to..
You can add dynamic subform into form builder, by calling
$formBuilder->add($subform /* FormBuilder */);
This subform will have name "form" if created with $this->createFormBuilder(); , that means that you can not add two or more subforms created this way - newer one will overwrite previous with same name.
If you need to add multiple sub-forms, you have to create their builders with
$this->get('form.factory')->createNamedBuilder($uniqName)

Answer 3

Without making classes... inside a Controller Action:
$subFormBuilder = $this->createFormBuilder(
null /* default data */,
['label' => 'Sub Form'] /* options */
)
->add('name');
$form = $this->createFormBuilder()
->add($subFormBuilder)
->add('number')
->getForm();