related content

gistfile1.php

/**
 * @param ArrayCollection $related Related item
 */
public function setRelated(ArrayCollection $related)
{
    $this->related = $related;

    foreach ($related as $relation) {
        if (! $relation->getRelated()->contains($this)) {
            $relation->addRelation($this);
        }
    }
}

// The addRelation($relation) method simply adds the relation to the related property:

$this->related[] = $relation;

//...and checks to see if the inverse relation needs to be added:

if (! $relation->getRelated()->contains($this)) {
    $relation->addRelation($this);
}