添加約束以比較提交形式中的兩個輸入

Question

帶有開始日期和結束日期的表單已提交，我需要一個約束條件 ，該約束條件將檢查結束日期是否晚於開始日期。

問題是我不能對表單本身進行約束，而只能對字段進行約束，因此我只能獲取字段值，而不能從其他表單輸入獲取值。

這是嘗試使用回調約束的代碼。

class MyCustomType extends AbstractType
{
/**
 * {@inheritdoc}
 */
public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder
    ->add('dateFrom', null, [
        'constraints' => [
            new NotBlank([
                'message' => 'Error'
            ])
        ],
    ])
    ->add('dateTo', null, [
        'constraints' => [
            new NotBlank([
                'message' => 'Error!'
            ]),
            new Callback(function($object, ExecutionContextInterface $context, $payload) {
                // Ėobject there is the field on which i check the constraint and i have no possible way to get the dateFrom value here
            })
        ],
    ])

例如：

• 開始日期2017-01-01結束日期2018-01-01該表格將有效。

• 開始日期2017-01-01結束日期2016-12-30表格無效。

Answer 1

 $form=$builder
    ->add('dateFrom', null, [
        'constraints' => [
            new NotBlank([
                'message' => 'Error'
            ])
        ],
    ])
    ->add('dateTo', null, [
        'constraints' => [
            new NotBlank([
                'message' => 'Error!'
            ]),
            new Callback(function($object, ExecutionContextInterface $context, $payload) {
                // Ėobject there is the field on which i check the constraint and i have no possible way to get the dateFrom value here
            })
        ],
    ]);

//Before submit controll date.
$builder->addEventListener(FormEvents::PRE_SUBMIT,function (FormEvent $event)
{

    //Form data
    $data=$event->getData();
    if($data['dateFrom']>$data['dateTo'])
    {
        //valid
    }
    else
    {
        //not valid
    }

}