FuelPHP Forums

You have to understand that every node in the try is (must be) a different object. If you do

$tree->tree_new_first_child_of($tree);

then you're trying to make the root a child of itself. Mess is guaranteed. ;-)

So you need two objects for operations like this, the $parent, that must already exist in the tree, and the $child, which must be a new tree model object, and then you can do something like:

$parent = Model_Tree::forge()->tree_get_root(); // $parent will now contain the root of the tree
$child = Model_Tree::forge(); // create a new child object
$child->tree_new_first_child_of($parent; // make $child a child of $parent

I don't think there are any examples out there. I converted it from DM to Fuel almost two years ago because someone asked for it, and haven't really looked at it since. I've got it on my todo list to rework it, and add it to the ORM package.

For a bit of background on Nested Sets, see http://www.evanpetersen.com/item/nested-sets.html

If I look at your code, I see

$parent = \MetadataModel_Tree::find_by_tree_id(\Session::get('tree_id'))->tree_select();                              
$child = \Metadata\Model_Tree::forge();
$child->tree_id = \Session::get('tree_id');                                    
$child->name = \Input::post('name');
$child->tree_new_first_child_of($parent);

I'm a bit confused by this code. You select a parent based on "tree_id". But "tree_id" identifies the entire tree, which can have lots of nodes. You need to select the parent on PK so you get the correct one.

The tree_select() is not needed, it is used to store the id of the tree you're working on when you;re navigating the tree. It needs a tree id as a parameter (which you don't give), but since you're only creating a new node, you don't need it at all.

Once you have the correct parent, this is indeed the way to add a new child (the first in the chain to be exact).

You need the specific model object that will be the parent. The only way to get that object (this is unrelated to nested sets) is to do a find() on the PK. If you don't get a specific parent node first, how would it know where to insert the child in the tree?

Once you have that parent you can forge() a new child object, do $child->tree_id = $parent->tree_id to make sure the child will be in the same tree as the parent.

1. If the tree is empty (i.e. no records with a specific "tree_id" exists, you first need to call tree_new_root(), creating the tree root:
   
   $root = Model_Tree::forge(array('name' => 'Root'))->tree_new_root();
    
2. You always have to start with an existing node, either the tree root, or another node. Adding or deleteing nodes is always an operation relative to another node. Note that you can not add siblings to a tree root.
   
   
3. You can add a node as a child (which means a level "lower" in the tree) or as a sibling (at the same level in the tree). Whether you use "previous" or "next" depends on which node you have selected as node to operate on.

So if you look at the image in the readme of the repo:

• "Customer Services" is a sibling of "Development Manager"
• "Assistent 1" is a child of "Customer Services"
• "Managing director" is parent of both "Customer Services" and  "Development Manager"

So if you have the object $custserv (which contains the node "Customer Services"), then

$custserv->tree_get_parent() will return the object for "Managing director"
$custserv->tree_get_first_child() will return the object for "Assistent 1"
$newnode->tree_new_first_child_of($custserv) will insert $newnode before "Assistent 1"
$newmode->tree_new_next_sybling_of($assistent1) will insert $newnode between "Assistent 1" and "Assistent 2"

Harro, so here is what I made so far:

http://bin.fuelphp.com/snippet/view/ax

Do you think it's a good start? Or any hints?

Just solved only Childs and no Siblings. I am thinking of how I will do that right now. Any idea?

Cheers, Kay