allow choosing empty value in CFLongChoice

CustomFields/CustomFieldLongChoice.php

@@ -19,7 +19,6 @@
 
 namespace Chill\CustomFieldsBundle\CustomFields;
 
-use Chill\CustomFieldsBundle\CustomFields\CustomFieldInterface;
 use Symfony\Component\Form\FormBuilderInterface;
 use Chill\CustomFieldsBundle\Entity\CustomField;
 use Chill\CustomFieldsBundle\EntityRepository\CustomFieldLongChoice\OptionRepository;
@@ -84,6 +83,8 @@ class CustomFieldLongChoice extends AbstractCustomField
             'choices_as_values' => true,
             'multiple' => false,
             'expanded' => false,
+            'required' => $customField->isRequired(),
+            'placeholder' => 'Choose a value',
             'group_by' => function(Option $option) use ($translatableStringHelper) {
                 if ($option->hasParent()) {
                     return $translatableStringHelper->localize($option->getParent()->getText());
@@ -137,12 +138,16 @@ class CustomFieldLongChoice extends AbstractCustomField
         
         return $this->templating
             ->render($template, array(
-                'values' => array($option)
+                'values' => $option === NULL ? array() : array($option)
                 ));
     }
 
     public function serialize($value, \Chill\CustomFieldsBundle\Entity\CustomField $customField)
     {
+        if ($value === NULL) {
+            return NULL;
+        }
+        
         if (!$value instanceof Option) {
             throw new \LogicException('the value should be an instance of '
                     . 'Chill\CustomFieldsBundle\Entity\CustomFieldLongChoice\Option, '

Resources/translations/messages.fr.yml

@@ -91,3 +91,4 @@ Text after the field: Texte après le champ
 
 #custom field long choice
 Options key: Clé des options
+Choose a value: Choisissez une valeur