Create helper to manage relationship removal

form/form_collections.rst

@@ -757,3 +757,83 @@ the relationship between the removed ``Tag`` and ``Task`` object.
 .. _`Owning Side and Inverse Side`: http://docs.doctrine-project.org/en/latest/reference/unitofwork-associations.html
 .. _`JSFiddle`: http://jsfiddle.net/847Kf/4/
 .. _`symfony-collection`: https://github.com/ninsuo/symfony-collection
+
+
+
+Optionnal helper to handle tags removals
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+You can optionnally reduce the code in your controller and make a reusable service to handle all your embedded form.
+
+First create a helper::
+
+ // src\Helper
+ use Doctrine\Common\Collections\ArrayCollection;
+ use Doctrine\ORM\EntityManagerInterface;
+
+ class Helper
+ {
+ private $em;
+
+ public function __construct(EntityManagerInterface $em)
+ {
+ $this->em = $em;
+ }
+
+ public function backupOriginalEntities($entities)
+ {
+ $original_entities = new ArrayCollection();
+
+ // Create an ArrayCollection of the current objects in the database
+ foreach ($entities as $entity) {
+ $original_entities->add($entity);
+ }
+
+ return $original_entities;
+ }
+
+ // this function removes only the relationship, removes the entity if $remove set to true
+ public function removeRelation($original_entities, $main_entity,$current_entities, $function_name, $remove=false)
+ { 
+ foreach ($original_entities as $entity) {
+ if (false === $current_entities->contains($entity)) {
+ $main_entity->$function_name($entity);
+
+ if($remove){
+ $this->em->remove($entity);
+ }
+ }
+ }
+ }
+ }
+
+Second edit your TaskController::
+
+ // src/Controller/TaskController.php
+ use App\Entity\Task;
+
+ // ...
+ public function edit($id, Request $request)
+ {
+ $entityManager = $this->getDoctrine()->getManager();
+ $task = $entityManager->getRepository(Task::class)->find($id);
+
+ if (!$task) {
+ throw $this->createNotFoundException('No task found for id '.$id);
+ }
+
+ $original_entities = $helper->backupOriginalEntities($event->getOrganizationTypes()); 
+ $editForm = $this->createForm(TaskType::class, $task);
+ $editForm->handleRequest($request);
+
+ if ($editForm->isValid()) {
+ // remove the relationship between the tag and the Task. depending on your needs : add the parameter true to remove the entity or let blank if you want to keep an orphan
+ $helper->removeRelation($original_entities,$event,$task->getTags(),'removeTag',true); // 
+ $entityManager->persist($task);
+ $entityManager->flush();
+
+ // redirect back to some edit page
+ return $this->redirectToRoute('task_edit', array('id' => $id));
+ }
+
+ // render some form template
+ }