对学说的@OneToMany ArrayCollection 进行排序

Question

我的问题接近this one，但与我的问题不完全吻合。

我在实体中有此列：

/**
 * @var ArrayCollection[SubjectTag]
 *
 * @ORM\OneToMany(targetEntity="SubjectTag", mappedBy="subject")
 * @Assert\Count(max = 10, maxMessage = "You can't create more than 10 tags.")
 * @Assert\Valid()
 */
protected $subjectTags;

我想按在SubjectTag.position 中定义的位置动态排序我的标签。

Answer 1

尝试像这样对Ordering To-Many Associations 使用教义2 ORM 功能：

/**
 * @var ArrayCollection[SubjectTag]
 *
 * @ORM\OneToMany(targetEntity="SubjectTag", mappedBy="subject")
 * @ORM\OrderBy({"position" = "ASC"})
 * @Assert\Count(max = 10, maxMessage = "You can't create more than 10 tags.")
 * @Assert\Valid()
 */
protected $subjectTags;

希望有帮助

Answer 2

我找到了解决方案，使用@HasLifeCycleCallbacks。

use Doctrine\ORM\Mapping as ORM;

/**
 * ...
 * @ORM\HasLifecycleCallbacks
 */
class Subject
{

    /**
     * @var ArrayCollection[SubjectTag]
     *
     * @ORM\OneToMany(targetEntity="SubjectTag", mappedBy="subject")
     * @Assert\Count(max = 10, maxMessage = "You can't create more than 10 tags.")
     * @Assert\Valid()
     */
    protected $subjectTags;


    /**
     * @ORM\PostLoad
     */
    public function onPostLoad()
    {
        $tags = $this->subjectTags->toArray();
        usort($tags, function($a, $b)
        {
            return $a->getPosition() == $b->getPosition() ? 0 : ($a->getPosition() > $b->getPosition() : -1 : 1);
        });
        $this->subjectTags = new ArrayCollection($tags);
    }

}