DataTransformer

TagsTransformer.php

<?php

namespace ForaSoft\ImproveClassBundle\Form\Transformer;

use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Persistence\ObjectManager;
use ForaSoft\ImproveClassBundle\Entity\Tag;
use Symfony\Component\Form\DataTransformerInterface;

class TagsTransformer implements DataTransformerInterface
{
    public function __construct(ObjectManager $manager)
    {
        $this->manager = $manager;
    }

    public function transform($tags)
    {

        return implode(',', $this->extractStrings($tags->toArray()));
    }

    public function reverseTransform($string)
    {
        $strings = explode(',',$string);
        $tags = $this->manager->getRepository('ForaSoftImproveClassBundle:Tag')->findBy(array('tag'=>$strings));
        $existingTags = $this->extractStrings($tags);
        $newTags = array_diff($strings,$existingTags);
        foreach ($newTags as $tag) {
            $newTag = new Tag();
            $newTag->setTag($tag);
            $tags[] = $newTag;
        }
        return $tags;
    }

    public static function extractStrings(array $tags)
    {
        return array_map(function (Tag $item) {
            return $item->getTag();
        },$tags);
    }

}