How to getPath of Gedmo Tree element using symfony3, doctrine2 and stofDoctrineExtensionsBundle

I am using Symfony v3.0.4, Doctrine v2.5.4 and StofDoctrineExtensionsBundle [1] in order to manage Tree structure.

To setup Tree structure I used documentation on Symfony.com [2] followed by documentatnion on GitHub [3].

Then I proceeded with tree setup - used tree entity from example [4] and used code in [5] to create a tree.

I did not use [6] and [7] as it seems not necessary (as far as I can tell tree works and displays without it). See update.

So far I have a tree structure in database and to display it I modified example [8]. Like this:

<?php

namespace AppBundle\Controller;

use AppBundle\Entity\Category;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;

class TreeController extends Controller
{
    /**
     * @Route("/tree", name="tree")
     */
    public function treeAction(Request $request)
    {
        $em = $this->getDoctrine()->getManager();

        $repo = $em->getRepository('AppBundle:Category');
        $options = array(
            'decorate' => true,
            'rootOpen' => '<ul>',
            'rootClose' => '</ul>',
            'childOpen' => '<li>',
            'childClose' => '</li>',
            'nodeDecorator' => function($node) {
                return '<a href="/some_path/...">'. $node['title'] .'</a>';
            }
        );

        $htmlTree = $repo->childrenHierarchy(
            null, /* starting from root nodes */
            false, /* false: load all children, true: only direct */
            $options
        );

        return $this->render('tree/tree_show.html.twig', array('project_tree' => $htmlTree));
    }
}

if I modify one line like this:

'nodeDecorator' => function($node) {
    return '<a href="/project_path/'. implode('/', getPath($node)) .'">'. $node['title'] .'</a>';
}

in order to get path to each element of the tree i get error:

Fatal error: Call to undefined function AppBundle\Controller\getPath()
500 Internal Server Error - FatalThrowableError

• [1] stofDoctrineExtensionsBundle on GitHub;
• [2] stofDoctrineExtensinsBundnle documentation on Symfony.com;
• [3] Gedmo Tree documentation on GitHub;
• [4] Gedmo Tree > Tree Entity example;
• [5] Gedmo Tree > Basic Usage Example;
• [6] DID NOT USE: Gedmo Tree > Tree Repositories;
• [7] Gedmo Tree > Use Abstract Repositories;
• [8] Tree html output example;
• [9] NestedTreeRepository has method getPath().

As seen in [9] NestedTreeRepositry has a method getPath().

Update: I tried [6] but did not manage to set it up. Then I tried [7] set it up ok, but still error remains the same!

Please advise. Thank you for your time and knowledge.

To use functon getPath() that exists in

"vendor/gedmo/doctrine-extensions/lib/Gedmo/Tree/Entity/Repository" in the file "NestedTreeRepository.php"

or in

"vendor/gedmo/doctrine-extensions/lib/Gedmo/Tree/Traits/Repository/ORM" in the file "NestedTreeRepositoryTrait.php"

one has to modify code block like this:

nodeDecorator' => function($node) use ($repo)
{
    return '<a href="/project_path/'. @implode('/', $repo->getPath($repo->findOneBy(array('id' => $node['id'])))) .'">'. $node['title'] .'</a>';
}

note added

use ($repo)

and

@implode('/', $repo->getPath($repo->findOneBy(array('id' => $node['id']))))

with this - there should be no undefined function error