Several updates:

* Option `class` is now optional. If not specified the Typeahead input will allow for non-entity lookups. The data passed is simply not transformed. It's up to your backend to do something useful with the values.
* Symfony form names with underscores will now work properly (eg: <form name="my_form">). Previously, form names with underscores would not POST properly.
* Replaced deprecated PropertyAccess::getPropertyAccessor() call with PropertyAccess::createPropertyAccessor().
* Removed unused TypeExtension.
* EntitiesToPropertyTransformer will no longer return an ArrayCollection. It returns a simple array instead.
* The `route` will receive extra parameters now to help it make decisions on how to return the results.
* Implemented `source` option to allow for a custom callback function that can return a list of matches (doesn't need to be AJAX).

Form/DataTransformer/EntitiesToPropertyTransformer.php

@@ -2,13 +2,10 @@
 
 namespace Lifo\TypeaheadBundle\Form\DataTransformer;
 
-use Symfony\Component\Form\DataTransformerInterface;
+use Doctrine\Common\Collections\Collection;
+use Doctrine\DBAL\Driver\DriverException;
 use Symfony\Component\Form\Exception\TransformationFailedException;
 use Symfony\Component\Form\Exception\UnexpectedTypeException;
-use Symfony\Component\PropertyAccess\PropertyAccess;
-use Doctrine\ORM\EntityManager;
-use Doctrine\Common\Collections\Collection;
-use Doctrine\Common\Collections\ArrayCollection;
 
 class EntitiesToPropertyTransformer extends EntityToPropertyTransformer
 {
@@ -26,14 +23,18 @@ public function transform($array)
             throw new UnexpectedTypeException($array, 'array');
         }
 
-        $return = array();
-        foreach ($array as $entity) {
-            $value = parent::transform($entity);
-            if ($value !== null) {
-                $return[] = $value;
+        if ($this->className) {
+            $return = array();
+            foreach ($array as $entity) {
+                $value = parent::transform($entity);
+                if ($value !== null) {
+                    $return[] = $value;
+                }
             }
+            return $return;
         }
-        return $return;
+
+        return $array;
     }
 
 
@@ -47,13 +48,20 @@ public function reverseTransform($array)
             throw new UnexpectedTypeException($array, 'array');
         }
 
-        $return = new ArrayCollection();
-        foreach ($array as $value) {
-            $entity = parent::reverseTransform($value);
-            if ($value !== null) {
-                $return[] = $entity;
+        if ($this->className) {
+            try {
+                return $this->em->createQueryBuilder()
+                    ->select('e')
+                    ->from($this->className, 'e')
+                    ->where('e.' . $this->property . ' IN (:ids)')
+                    ->setParameter('ids', $array)
+                    ->getQuery()
+                    ->getResult();
+            } catch (DriverException $ex) {
+                throw new TransformationFailedException('One or more "' . $this->property . '" values are invalid');
             }
         }
-        return $return;
+
+        return $array;
     }
 }

Form/DataTransformer/EntityToPropertyTransformer.php

@@ -16,44 +16,50 @@ class EntityToPropertyTransformer implements DataTransformerInterface
     protected $className;
     protected $property;
     protected $unitOfWork;
+    protected $accessor;
 
     public function __construct(EntityManager $em, $class, $property = 'id')
     {
         $this->em = $em;
         $this->unitOfWork = $this->em->getUnitOfWork();
         $this->className = $class;
         $this->property = $property;
+        $this->accessor = PropertyAccess::createPropertyAccessor();
     }
 
     public function transform($entity)
     {
-        if (null === $entity) {
+        if (empty($entity)) {
             return null;
         }
 
-        //if (!$this->unitOfWork->isInIdentityMap($entity) and !$this->unitOfWork->isScheduledForInsert($entity)) {
-        //    throw new TransformationFailedException("Entities must be managed");
-        //}
+        if ($this->className) {
+            if (!empty($this->property)) {
+                return $this->accessor->getValue($entity, $this->property);
+            } else {
+                return current($this->unitOfWork->getEntityIdentifier($entity));
+            }
+        }
 
-        return !empty($this->property)
-            ? PropertyAccess::getPropertyAccessor()->getValue($entity, $this->property)
-            : current($this->unitOfWork->getEntityIdentifier($entity));
+        return $entity;
     }
 
 
     public function reverseTransform($value)
     {
-        if ($value === '' or $value === null) {
+        if (empty($value)) {
             return null;
         }
 
-        $repo = $this->em->getRepository($this->className);
-        if (!empty($this->property)) {
-            $entity = $repo->findOneBy(array($this->property => $value));
-        } else {
-            $entity = $repo->find($value);
+        if ($this->className) {
+            $repo = $this->em->getRepository($this->className);
+            if (!empty($this->property)) {
+                return $repo->findOneBy(array($this->property => $value));
+            } else {
+                return $repo->find($value);
+            }
         }
 
-        return $entity;
+        return $value;
     }
 }

Form/Type/TypeaheadType.php

@@ -53,16 +53,16 @@ public function buildForm(FormBuilderInterface $builder, array $options)
     public function finishView(FormView $view, FormInterface $form, array $options)
     {
         parent::finishView($view, $form, $options);
-        //$cfg = $form->getConfig();
 
         // assign some variables to the view template
-        $vars = array('render', 'route', 'route_params', 'property',
-            'minLength', 'items', 'delay', 'spinner',
-            'multiple', 'allow_add', 'allow_remove', 'empty_value',
-            'resetOnSelect', 'callback');
+        $vars = array(
+            'render', 'route', 'route_params', 'property', 'minLength', 'items', 'delay', 'spinner', 'multiple',
+            'allow_add', 'allow_remove', 'empty_value', 'resetOnSelect', 'callback', 'source',
+        );
         foreach ($vars as $var) {
             $view->vars[$var] = $options[$var];
         }
+        $view->vars['simple'] = empty($options['class']);
 
         // convert the route into an URL
         if (!empty($options['route'])) {
@@ -93,28 +93,28 @@ public function setDefaultOptions(OptionsResolverInterface $resolver)
      */
     public function configureOptions(OptionsResolver $resolver)
     {
-        $resolver->setRequired(array('class', 'render', 'route'));
+        $resolver->setRequired(array('render'));
         $resolver->setDefaults(array(
             'em'            => null,
             'query_builder' => null,
-            'property'      => null,
+            'class'         => null,
+            'property'      => 'id',
             'empty_value'   => '',
+            'route'         => null,
             'route_params'  => null,
-
+            'source'        => null,
             'multiple'      => false,
             'allow_add'     => false,
             'allow_remove'  => false,
-
             'delay'         => 250,
             'minLength'     => 2,
             'items'         => 10,
             'spinner'       => 'glyphicon glyphicon-refresh spin',
+            'callback'      => null,
+            'compound'      => false,
             'resetOnSelect' => function (Options $options) {
                 return $options['multiple'];
             },
-            'callback'      => null,
-
-            'compound'      => false, //function(Options $options){ return $options['multiple']; },
         ));
     }