两个未映射的隐藏字段已添加到表单类型中，以在 PRE_SUBMIT 表单事件中启用数据修改。但是，正如在 Netbeans 调试中观察到的，这些字段及其数据在 Form Event 中不可用。还有第三个可用的未映射字段。测试表明，隐藏字段并不是这些字段未出现在事件中的原因。隐藏字段在表单中正确呈现。奇怪的是，当使用
$form->getErrorsAsString();
在控制器中，字段出现在表单错误字符串中（因为没有错误）。
表格类：
class HouseholdType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('active', 'choice', array(
'choices' => array('1' => 'Yes', '0' => 'No'),
'data' => 1,
))
->add('addresses', 'collection', array(
'type' => new AddressType(),
'allow_add' => true,
'allow_delete' => true,
'by_reference' => false,
'prototype' => true,
'prototype_name' => '__address__',
))
->add('arrivalmonth', new Type\MonthType(), array(
'empty_value' => false,
'data' => date('n'),
))
->add('arrivalyear', new Type\YearType(), array(
'empty_value' => false,
))
->add('foodStamps', 'choice', array(
'choices' => array('0' => 'No', '1' => 'Yes', '2' => 'Appl.'),
'empty_value' => false,
))
//this field appears at Form Event
->add('isHead', 'choice', array(
'expanded' => true,
'mapped' => false,
)
)
//the following two fields do not appear in Form Event
->add('headId', 'hidden', array(
'mapped' => false,
))
->add('v1Date', 'hidden', array(
'mapped' => false,
))
->add('members', 'collection', array(
'type' => new MemberType(),
'allow_add' => true,
'allow_delete' => true,
'by_reference' => false,
'prototype' => true,
))
->add('wic', 'choice', array(
'choices' => array('0' => 'No', '1' => 'Yes', '2' => 'Appl.'),
'empty_value' => false,
))
;
$builder->addEventListener(FormEvents::PRE_SUBMIT, function (FormEvent $event) {
$data = $event->getData();
$event->setData($data);
});
}