/**
* Transforms entities into choice keys
*
* @param Collection|object A collection of entities, a single entity or
* NULL
* @return mixed An array of choice keys, a single key or
* NULL
*/
protected function transform($collectionOrEntity)
{
if (null === $collectionOrEntity) {
return $this->getOption('multiple') ? array() : '';
}
if (count($this->identifier) > 1) {
// load all choices
$availableEntities = $this->getEntities();
if ($collectionOrEntity instanceof Collection) {
$result = array();
foreach ($collectionOrEntity as $entity) {
// identify choices by their collection key
$key = array_search($entity, $availableEntities);
$result[] = $key;
}
} else {
$result = array_search($collectionOrEntity, $availableEntities);
}
} else {
if ($collectionOrEntity instanceof Collection) {
$result = array();
foreach ($collectionOrEntity as $entity) {
$result[] = current($this->getIdentifierValues($entity));
}
} else {
$result = current($this->getIdentifierValues($collectionOrEntity));
}
}
return parent::transform($result);
}
