Validating dynamically loaded choices in Symfony 2 - symfony

Question

I have a choice field type named *sub_choice* in my form whose choices will be dynamically loaded through AJAX depending on the selected value of the parent choice field, named *parent_choice*. Loading the choices works perfectly but I'm encountering a problem when validating the value of the sub_choice upon submission. It gives a "This value is not valid" validation error since the submitted value is not in the choices of the sub_choice field when it was built. So is there a way I can properly validate the submitted value of the sub_choice field? Below is the code for building my form. I'm using Symfony 2.1.
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->add('parent_choice', 'entity', array(
'label' => 'Parent Choice',
'class' => 'Acme\TestBundle\Entity\ParentChoice'
));
$builder->add('sub_choice', 'choice', array(
'label' => 'Sub Choice',
'choices' => array(),
'virtual' => true
));
}

Answer 1

To do the trick you need to overwrite the sub_choice field before submitting the form:
public function buildForm(FormBuilderInterface $builder, array $options)
{
...
$builder->addEventListener(FormEvents::PRE_SUBMIT, function (FormEvent $event) {
$parentChoice = $event->getData();
$subChoices = $this->getValidChoicesFor($parentChoice);
$event->getForm()->add('sub_choice', 'choice', [
'label' => 'Sub Choice',
'choices' => $subChoices,
]);
});
}

Answer 2

this accept any value
$builder->addEventListener(FormEvents::PRE_SUBMIT, function (FormEvent $event) {
$data = $event->getData();
if(is_array($data['tags']))$data=array_flip($data['tags']);
else $data = array();
$event->getForm()->add('tags', 'tag', [
'label' => 'Sub Choice',
'choices' => $data,
'mapped'=>false,
'required'=>false,
'multiple'=>true,
]);
});

Answer 3

Adding an alternate approach for future readers since I had to do a lot of investigation to get my form working. Here is the breakdown:
Adding a "New" option to a dropdown via jquery
If "New" is selected display new form field "Custom Option"
Submit Form
Validate data
Save to database
jquery code for twig:
$(function(){
$(document).ready(function() {
$("[name*='[custom_option]']").parent().parent().hide(); // hide on load
$("[name*='[options]']").append('<option value="new">New</option>'); // add "New" option
$("[name*='[options]']").trigger("chosen:updated");
});
$("[name*='[options]']").change(function() {
var companyGroup = $("[name*='[options]']").val();
if (companyGroup == 'new') { // when new option is selected display text box to enter custom option
$("[name*='[custom_option]']").parent().parent().show();
} else {
$("[name*='[custom_option]']").parent().parent().hide();
}
});
});
// Here's my Symfony 2.6 form code:
->add('options', 'entity', [
'class' => 'Acme\TestBundle\Entity\Options',
'property' => 'display',
'empty_value' => 'Select an Option',
'mapped' => true,
'property_path' => 'options.optionGroup',
'required' => true,
])
->add('custom_option', 'text', [
'required' => false,
'mapped' => false,
])
To handle the form data we need to use the PRE_SUBMIT form event.
$builder->addEventListener(FormEvents::PRE_SUBMIT, function (FormEvent $event) {
$data = $event->getData();
$form = $event->getForm();
if (isset($data['options']) && $data['options'] === 'new') {
$customOption = $data['custom_option'];
// todo: handle this better on your own
if (empty($customOption)) {
$form->addError(new FormError('Please provide a custom option'));
return;
}
// Check for a duplicate option
$matches = $this->doctrine->getRepository('Acme\TestBundle\Entity\Options')->matchByName([$customOption]);
if (count($matches) > 0) {
$form->addError(new FormError('Duplicate option found'));
return;
}
// More validation can be added here
// Creates new option in DB
$newOption = $this->optionsService->createOption($customOption); // return object after persist and flush in service
$data['options'] = $newOption->getOptionId();
$event->setData($data);
}
});
Let me know if ya'll have any questions or concerns. I know this might not be the best solution but it works. Thanks!

Answer 4

you cannot not build the sub_choice validation because during you config its validator you don't know which values are valid (values depend on value of parent_choice).
What you can do is to resolve parent_choice into entity before you make new YourFormType() in your controller.
Then you can get all the possible values for sub_choice and provide them over the form constructor - new YourFormType($subChoice).
In YourFormType you have to add __construct method like this one:
/**
* #var array
*/
protected $subChoice = array();
public function __construct(array $subChoice)
{
$this->subChoice = $subChoice;
}
and use provided values in form add:
$builder->add('sub_choice', 'choice', array(
'label' => 'Sub Choice',
'choices' => $this->subChoice,
'virtual' => true
));

Answer 5

Suppose for sub choices you have id's right ?
Create and empty array with a certain number of values and give it as a choice
$indexedArray = [];
for ($i=0; $i<999; $i++){
$indexedArray[$i]= '';
}
then 'choices' => $indexedArray, :)