How to make Symfony2 form optional field not null on save - php

Question

I have an image field which is optional. When you upload image, it will save the filename on the database (using events via doctrine ).
The problem is when you edit an already uploaded form and don't add an image, it makes the image field to null.
Is there a way to check / remove the field value setting to null if no image is uploaded?
The Entity, Form code is as below :
class Product
{
/**
* #ORM\Column(type="string", nullable=true)
*
* #Assert\Image
*/
private $image;
}
Form
class ProductType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->add('image', FileType::class, [
'required' => !$options['update'],
]);
$builder->addEventListener(FormEvents::PRE_SET_DATA, function (FormEvent $event) {
$form = $event->getForm();
$product = $event->getData();
if (null == $form->get('image')->getData()) {
// $form->remove('image');
}
});
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'AppBundle\Entity\Product'
));
}
public function getBlockPrefix()
{
return 'appbundle_product';
}
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
$resolver->setRequired([
'update',
]);
}
}
// In controller
$editForm = $this->createForm(
'AppBundle\Form\ProductType',
$product,
[
'update' => true
]
);

Answer 1

You need the event PRE_SUBMIT, try this:
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->add('image', FileType::class, [
'required' => !$options['update'],
]);
$builder->addEventListener(FormEvents::PRE_SUBMIT, function (FormEvent $event) {
$form = $event->getForm();
$product = $event->getData();
if(empty($product['image'])){
//No new image for existing field was given. Make field disabled so doctrine will not update with empty
$config = $event->getForm()->get('image')->getConfig();
$options = $config->getOptions();
$event->getForm()->add(
'image',
$config->getType()->getName(),
array_replace(
$options,
['disabled' => true]
)
);
}
});
}

Answer 2

Symfony Form has submit() method, which takes two arguments, $submittedData and $clearMissing
/**
* Submits data to the form, transforms and validates it.
*
* #param null|string|array $submittedData The submitted data
* #param bool $clearMissing Whether to set fields to NULL
* when they are missing in the
* submitted data.
*
* #return FormInterface The form instance
*
* #throws Exception\AlreadySubmittedException If the form has already been submitted.
*/
public function submit($submittedData, $clearMissing = true);
$clearMissing parameter is by the default set to true.
If you, in your controller do this: $form->submit($submittedData, false);, your image will not be set to null.
https://symfony.com/doc/current/form/direct_submit.html#calling-form-submit-manually
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