Automatically add css class

Form/DataTransformer/EntitiesToPropertyTransformer.php

@@ -8,6 +8,7 @@
 
 namespace Tetranz\Select2EntityBundle\Form\DataTransformer;
 
+use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\ORM\EntityManager;
 use Symfony\Component\Form\DataTransformerInterface;
 
@@ -30,6 +31,7 @@ public function transform($entities)
             return '';
         }
 
+        // return an array of initial values as html encoded json
         $data = array();
 
         foreach($entities as $entity) {
@@ -49,11 +51,11 @@ public function transform($entities)
 
     public function reverseTransform($values)
     {
-        // $values has a leading comma
+        // remove the 'magic' non-blank value added in fields.html.twig
         $values = ltrim($values, 'x,');
 
         if (null === $values || '' === $values) {
-            return array();
+            return new ArrayCollection();
         }
 
         $ids = explode(',', $values);

Form/DataTransformer/EntityToPropertyTransformer.php

@@ -30,6 +30,8 @@ public function transform($entity)
             return '';
         }
 
+        // return the initial values as html encoded json
+
         $text = is_null($this->textProperty)
             ? (string) $entity
             : $entity->{'get' . $this->textProperty}();

README.md

@@ -78,7 +78,6 @@ Here's an example:
 $builder
    ->add('country', 'tetranz_select2entity', [
             'multiple' => true,
-            'attr' => ['class' => 'select2entity'],
             'remote_route' => 'tetranz_test_default_countryquery',
             'class' => '\Tetranz\TestBundle\Entity\Country',
             'text_property' => 'Name',
@@ -88,8 +87,6 @@ $builder
         ])
 ```
 
-You must include `'attr' => ['class' => 'select2entity']` to give it the required class for jQuery to find it. (That will probably be changed soon so it gets added automatically).
-
 ##Options##
 * `class` is your entity class. Required
 * `text_property` This is the entity property used to retrieve the text for existing data. A getter method is created by prepending this with `get` so it probably needs to be proper case. e.g., `Name`.

Resources/views/Form/fields.html.twig

@@ -9,7 +9,15 @@
         'data-placeholder':placeholder
     }) %}
 
+    {# Add class for jQuery for find it #}
+    {% set attr = attr|merge({ 'class': (attr.class|default('') ~ ' select2entity')|trim }) %}
+
+    {# A bit of a kludge here.
+    It seems to work more smoothly if we put the initial value into data-value rather than the value attribute.
+    But ... value needs to be non-blank for initSelection in the js to fire.
+    We need to remove this value in EntitiesToPropertyTransformer #}
     {% set value = 'x' %}
+
     {% set type = type|default('hidden') %}
     {{ block('form_widget_simple') }}
 {% endblock %}