Display a tree hierarchy

I have a Category entity designed to represent a Forum category. I used StofDoctrineExtensionsBundle in order to use its Tree annotation, in order to have a hierarchy in categories. Now, I would like to represent that hierarchy in a string, some like Category/Subcategory/Subsubcategory/Foo. How can I get all the hierarchy in an unique request with Doctrine ?

// Category.php

use Doctrine\Common\Collections\ArrayCollection;
use Gedmo\Mapping\Annotation as Gedmo;
use Doctrine\ORM\Mapping as ORM;

/**
 * @Gedmo\Tree(type="nested")
 * @ORM\Table()
 * @ORM\Entity(repositoryClass="PC\ForumBundle\Entity\Repository\CategoryRepository")
 */
class Category
{
    /**
     * @ORM\Column(type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue
     */
    private $id;

    /**
     * @ORM\Column(length=64)
     */
    private $title;

    /**
     * @ORM\Column(type="text", nullable=true)
     */
    private $description;

    /**
     * @Gedmo\Slug(fields={"title"})
     * @ORM\Column(length=64, unique=true)
     */
    private $slug;

    /**
     * @Gedmo\TreeLeft
     * @ORM\Column(type="integer")
     */
    private $lft;

    /**
     * @Gedmo\TreeRight
     * @ORM\Column(type="integer")
     */
    private $rgt;

    /**
     * @Gedmo\TreeParent
     * @ORM\ManyToOne(targetEntity="Category", inversedBy="children")
     * @ORM\JoinColumn(name="parent_id", referencedColumnName="id", onDelete="CASCADE")
     */
    private $parent;

    /**
     * @Gedmo\TreeRoot
     * @ORM\Column(type="integer", nullable=true)
     */
    private $root;

    /**
     * @Gedmo\TreeLevel
     * @ORM\Column(name="lvl", type="integer")
     */
    private $level;

    /**
     * @ORM\OneToMany(targetEntity="Category", mappedBy="parent")
     */
    private $children;

// ...

I finally found how to do it :

• Make your repository class extend Gedmo\Tree\Entity\Repository\NestedTreeRepository
• Call the method getPath($node) on it.

Example :

// Assuming $category is provided by a ParamConverter
public function indexAction(Category $category = null)
{
    return array(
        'category' => $category,
        'path' => $this->repo->getPath($category)
    );
}