XF 2.0 Thread action not returning correct nodeTree with 'where' condition

[Marcel]

    public function actionUnarchive(ParameterBag $params)
    {
        $thread = $this->assertViewableThread($params->thread_id);
        $forum = $thread->Forum;
        $currentForumId = $forum->node_id;

        /** @var \XF\Repository\Node $nodeRepo */
        $nodeRepo = $this->repository('XF:Node');
        $nodes = $this->app()->repository('XF:Node')->findNodesForList()->fetch();
        $this->app()->repository('XF:Node')->filterViewable($nodes);
        $viewParams = [
            'thread' => $thread,
            'forum' => $forum,
            'prefixes' => $forum->getUsablePrefixes(),
            'nodeTree' => $nodeRepo->createNodeTree($nodes)
        ];
       return $this->view('XF:Thread\Move', 'thread_move', $viewParams);
    }

That's the function. adding a dump($nodes) to the code, shows me a full list of nodes. Great, and the dropdown menu matches this.
I want to restrict that list of forums to only those that have a particular field set in the xf_node table, so I want to add a 'where' condition to this line

$nodes = $this->app()->repository('XF:Node')->findNodesForList()->where('ut_archive_enabled','=','1')->fetch();

This gives me an 'unknown column' error. Fine. I'll step back a bit and just try and match the node_id for now.

$nodes = $this->app()->repository('XF:Node')->findNodesForList()->where('node_id','=','25')->fetch();
This doesnt throw an error, but the dropdown list on the thread_move template is empty.
However, dump($nodes) shows a restricted list of nodes which is just what I want.
However, it doesn't reflect in the template? The dropdown list is empty.

This may sound like a stupid question (I've only just stepped into rewriting my addons for XF2), but where am I going wrong?
The whole finder/entity/repository is giving my head a bit of a pickle.

 

[Mike]

A tree starts at a root and then follows down branches eventually getting to a leaf (which has no children). If you filter down so that your list only has a leaf -- or more specifically, doesn't have anything that is connected to the root -- you won't have a tree to display.

Essentially, you need the entire path to the nodes you want to be included, otherwise there isn't a way to display the node in question in a tree. To do this, you need to filter after you have the full set of data.

The only other alternative would be to essentially ignore the tree setup of nodes.

 

[Marcel]

Thanks Mike. That does make sense. So pull all the nodes into a tree and then cut off the branches and leaves I don't want, based on my criteria?
I did touch on the thought of doing it like that, but it seemed counter-intuitive...security wise.
There's no technical basis for my assumption of course, just ..... logical? Kind of like offering up a full set of keys and then taking back the ones you don't want them to have.

Thanks for the reply, I'll re-evaluate my approach