Symfony, Many to many with attributes self referencing

Question

I have an entity Room that has a ManyToMany relationship with itself, and this relationship (RoomLinkRoom) bears an attribute "weight" : a Room can be linked to several Rooms, with an ordering(weight) value (and potentially other attributes).

The code i have sofar handles the linkage of one or more RoomTo to a RoomFrom. Let's say we have : RoomA : 1 RoomB : 2

In the Room Form, we can add RoomB to RoomA we have this entry in RoomLinkRoom :

RoomFromId : 1 RoomToId : 2

But this is only half of what i need : i also need the reverse part management.

When RoomFromId,1 is linked to RoomToId,2 i also want to add in this intermediate entity : RoomFromId,2, RoomToId,1

And then i also have to manage the delete part : If i remove Room A, the entry (roomFrom, roomTo) : (1, 2) will be deleted but the reverse (2, 1) must also be deleted.

How can i achieve this ? What is the best (cleanest ?) way to handle this whole problem ? Is there a "standard pattern" ("automatic" or not) for handling this case ? I'm not sure how to procede, but maybe it involves events, like postFlush ? But will it be able to take care also of the delete for the "reverse" (To) side ?

The (relevant part of the) Entities are :

<?php

use Doctrine\ORM\Mapping as ORM;
use Doctrine\Common\Collections\ArrayCollection;
use MyBundle\Entity\RoomLinkRoom;

/**
 * Room
 *
 * @ORM\Table(name="room")
 * @ORM\Entity(repositoryClass="MyBundle\Repository\RoomRepository")
 * @ORM\HasLifecycleCallbacks()
 */
class Room
{
  /**
   * @ORM\Column(name="id", type="integer")
   * @ORM\Id
   * @ORM\GeneratedValue(strategy="IDENTITY")
   */
  private $id;

  /**
   * @ORM\Column(name="name", type="string", length=255, nullable=false)
   */
  private $name;

  /**
   * @ORM\OneToMany(
   *    targetEntity="MyBundle\Entity\RoomLinkRoom", mappedBy="roomFrom",
   *    cascade={"persist", "remove"}, orphanRemoval=TRUE)
   */
  private $roomFromLinks;

  /**
   * @ORM\OneToMany(
   *    targetEntity="MyBundle\Entity\RoomLinkRoom", mappedBy="roomTo",
   *    cascade={"persist", "remove"}, orphanRemoval=TRUE)
   */
  private $roomToLinks;

  public function __construct()
  {
    $this->roomFromLinks = new ArrayCollection();
    $this->roomToLinks = new ArrayCollection();
  }

  public function addRoomFromLink(RoomLinkRoom $roomFromLink)
  {
    $this->roomFromLinks[] = $roomFromLink;
    $roomFromLink->setRoomFrom($this);
    return $this;
  }

  public function removeRoomFromLink(RoomLinkRoom $roomFromLink)
  {
    $this->roomFromLinks->removeElement($roomFromLink);
  }

  public function getRoomFromLinks()
  {
    return $this->roomFromLinks;
  }

  public function addRoomToLink(RoomLinkRoom $roomToLink)
  {
    $this->roomToLinks[] = $roomToLink;
    $roomToLink->setRoomTo($this);
    return $this;
  }

  public function removeRoomToLink(RoomLinkRoom $roomToLink)
  {
    $this->roomToLinks->removeElement($roomToLink);
  }

  public function getRoomToLinks()
  {
    return $this->roomToLinks;
  }
}

And

<?php
use Doctrine\ORM\Mapping as ORM;
use MyBundle\Entity\Room;
use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;

/**
 * RoomLinkRoom.
 *
 * @ORM\Table(name="roomlinkroom", indexes={
 *      @ORM\Index(name="FK_RoomLinkRoom_roomfromId", columns={"roomfromId"}),
 *      @ORM\Index(name="FK_RoomLinkRoom_roomtoId", columns={"roomtoId"}),
 * })
 * @ORM\Entity(repositoryClass="MyBundle\Repository\RoomLinkRoomRepository")
 * @UniqueEntity(
 *     fields={"roomFrom", "roomTo"},
 *     errorPath="weight",
 *     message="Ces salles sont déjà liées."
 * )
 */
class RoomLinkRoom
{
  /**
   * @var int
   *
   * @ORM\Column(name="id", type="integer")
   * @ORM\Id
   * @ORM\GeneratedValue(strategy="AUTO")
   */
  private $id;

  /**
   * @ORM\ManyToOne(targetEntity="MyBundle\Entity\Room", inversedBy="roomFromLinks")
   * @ORM\JoinColumn(name="roomFromId", referencedColumnName="id", nullable=false)
   */
  private $roomFrom;

  /**
   * @ORM\ManyToOne(targetEntity="MyBundle\Entity\Room", inversedBy="roomToLinks")
   * @ORM\JoinColumn(name="roomToId", referencedColumnName="id", nullable=false)
   */
  private $roomTo;

  public function getId()
  {
      return $this->id;
  }

  public function setRoomFrom(Room $roomFrom)
  {
    $this->roomFrom = $roomFrom;
    return $this;
  }

  public function getRoomFrom()
  {
    return $this->roomFrom;
  }

  public function setRoomTo(Room $roomTo)
  {
    $this->roomTo = $roomTo;
    return $this;
  }


  public function getRoomTo()
  {
    return $this->roomTo;
  }
}

I've tried in the controller to add after the flush :

if ($form->isSubmitted() && $form->isValid()) {
//...
  $em->persist($room);
  $em->flush();

  //look for existing relationship between To and From
  foreach ($room->getRoomFromLinks() as $rfl){
    $res = $em->getRepository('MyBundle:RoomLinkRoom')
      ->findBy(['roomFrom' => $rfl->getRoomTo(), 'roomTo' => $room]);
    //add the reverse side
    if (count($res) === 0){
      $rlr = new RoomLinkRoom();
      $rlr->setRoomFrom($rfl->getRoomTo());
      $rlr->setRoomTo($room);
      $em->persist($rlr);
      $em->flush();
    }
  }
  //redirect
}

This adds the reverse/complementary entry, but i still don't know if this is clean/bugproof. But i'm sure this doesn't take care of the delete.

So does anyone have used this kind of relationship ?

I've seen other discussions here (for instance, this one) but, they don't seem to care for this "reverse" management.

Thank you in advance.

Symfony, Many to many with attributes self referencing

0 Answers0