Entity persist finds new relationship that existed before - symfony

Question

Hi I have an action which adds people to a group.
In order to increase the usability the form for it removes the people that are already in the group.
My controller action looks like this:
public function addAction(UserGroup $userGroup)
{
$tempGroup = new UserGroup();
foreach ($userGroup->getUsers() as $user) {
$tempGroup->addUser($user);
}
$form = $this->container->get('form.factory')->create(new UserGroupQuickType(), $tempGroup);
$request = $this->container->get('request');
if ('POST' === $request->getMethod()) {
$form->submit($request);
if ($form->isValid()) {
$group = $form->getData();
/** #var $myUserManager UserManager */
$myUserManager = $this->container->get('strego_user.user_manager');
/** #var $em EntityManager */
$em = $this->container->get('em');
foreach ($group->getUsers() as $toInvite) {
$userGroup->addUser($toInvite);
}
$em->persist($userGroup);
$em->flush($userGroup);
}
}
return array(
'form' => $form->createView(),
'userGroup' => $userGroup
);
}
This code throws an exception:
A new entity was found through the relationship 'Strego\UserBundle\Entity\UserGroup#users'
that was not configured to cascade persist operations for entity: Degi.
To solve this issue: Either explicitly call EntityManager#persist() on
this unknown entity or configure cascade persist this
association in the mapping for example #ManyToOne(..,cascade={"persist"}).
The new found relation with was already there before. Meaning the user "Degi" was already in the group and is not a new entity.
I can avoid this error if I'll leave out the persist but then I'll get an exception: Entity has to be managed or scheduled for removal for single computation.
This is caused by the fact that my "usergroup" entity has the whole time a entity status of 3 (= detached)
I have used the same logic (with temp group etc.) for an entity that has 1 to 1 relationship to my usergroup and from there I can easily add people even to the group.
But not with this action, which is logically doing the exact same thing.
UPDATE:
My previous update was leading in the wrong direction. But here in comparison the (almost) same controller that works:
public function addAction(BetRound $betRound)
{
$userGroup = new UserGroup();
foreach ($betRound->getUsers() as $user) {
$userGroup->addUser($user);
}
$form = $this->createForm(new UserGroupQuickType(), $userGroup);
$request = $this->getRequest();
if ('POST' === $request->getMethod()) {
$form->submit($request);
if ($form->isValid()) {
/** #var $betRoundManager BetRoundManager */
$betRoundManager = $this->container->get('strego_tipp.betround_manager');
/** #var $myUserManager UserManager */
$myUserManager = $this->container->get('strego_user.user_manager');
$group = $form->getData();
foreach ($group->getUsers() as $toInvite) {
if (!$betRound->getUserGroup()->hasUser($toInvite)) {
$betRound->getUserGroup()->addUser($toInvite);
}
}
$this->getDoctrine()->getManager()->flush();
return $this->redirect($this->generateUrl('betround_show', array('id' => $betRound->getId())));
}
}
return array(
'form' => $form->createView(),
'betRound' => $betRound
);
}

Answer 1

This is expected behavior since your have relationship to, not really a new entity but unmanaged object.
While iterating you could try merging $toInvite. Don't worry, if objects you acquired via form have an appropriate identifier (#Id) value set they would be just reloaded from databases instead of marked for insertion. Newly added objects, on the other hand, will be marked.
So, before trying anything, ensure that each of old $toInvite have an ID set.
foreach ($group->getUsers() as $toInvite) {
$em->merge($toInvite);
$userGroup->addUser($toInvite);
}
// safe to do now, all of the added users are either reloaded or marked for insertion
$em->perist($usetGroup);
$em->flush($userGroup);
Hope this helps.

Answer 2

This is happening because $userGroup is already an entity which already exists and $toInvite is a new entity and you are trying to flush $userGroup. To make this code working you need to specify cascade={"persist"} in your entity file (Annotations or yaml whichever you prefer).
Other solution is to do the reverse and persist $toInvite
foreach ($group->getUsers() as $toInvite) {
$toInvite->setUserGroup($userGroup);
$em->persist($toInvite);
}
$em->flush();
I think the first option would be a better choice

Answer 3

After several attempts I found out that this issue were actually 2 issues:
1. I had a listener that updated some rows on persist even if it was not necessary.
2. The paramconverter somehow detaches the entities that are coming in. Which means that my UserGroup and all my users in it are detached. As soon as they are added again to the Usergroup, those Entities seem to be "new" for the EM. Therefore I needed to merge all users AND fix my listener that updates the "createdBy", which otherwise would have also needed to been merged.