Deleting and appending to a subtree

[clapas]

There seems to be a problem with tree updating.

Let's suppose I have a simple 2 level tree created using the model methods create() and append(), i.e. only a root node and a couple children. The tree is correct in the begining.

Now, if I replace the whole 2nd level, i.e. everything under my root node, and append new nodes to the root node, the _lft and _rgt numbers for the first appended child outbound the parents'. Despite the children() method returning all the children nodes (because the parent_id property links them correctly), a call to descendantsOf(), which traverses the tree using the _lft and _rgt numbers, leave the first child out.

The procedure I used to replace the 2nd level is by calling delete() on every child to be removed and then calling append() on the root node for each new child. It is always the first newly appended child which is left out because the _lft and _rgt numbers on the parent don't include this child's ones.

[lazychaser]

Did you try to check the tree consistency? What is says?

[clapas]

I just checked it.

isBroken: boolean true
countErrors: array (size=3)
  'oddness' => int 0
  'duplicates' => int 0
  'wrong_parent' => int 6

Currently in my example I have the root node and 6 children. The error appears besides "wrong_parent", but the parent_id looks ok actually. It is the _lft and _rgt that look bad to me, but only for the first child, as I said.

Cheers

[lazychaser]

Show me the code

[clapas]

public function update($id) {
    $data = [
        'id' => 2,
        'name' => 'Numbered',
        'children' => [
            0 => [
                'id' => 3,
                'parent_id' => 2,
                'name' => 'Seat 1'
            ]
            ...
        ]
    ];
    if (!$fs = FacilitySection::find($id)) abort(400);
    DB::beginTransaction();
    try {
        $fs->fill($data);
        $fs->save();
        foreach ($fs->children as $ch) $ch->delete();
        if (isset($data['children']) and is_array($data['children'])) 
            foreach ($data['children'] as $ch) $this->appendSubtree($fs, $ch);
        DB::commit();
    } catch (Exception $e) {
        DB::rollback();
        Log::error($e->errorMessage());
        throw $e;
    }
}
private function appendSubtree($fs, $subtree) {
    // allow only fillable attributes
    $data = array_intersect_key($subtree, array_flip($fs->getFillable()));
    $node = FacilitySection::create($data);
    $fs->append($node);
    if (isset($subtree['children']) and is_array($subtree['children'])) foreach ($subtree['children'] as $ch)
        $this->appendSubtree($node, $ch);
}

Notes

• My FacilitySection class inherits from your Kalnoy\Nestedset\Node class.
• I receive the data through an HTML Post, but I put it verbatim for you to understand better.
• Please notice that I ignore the children ids and parent_ids (I receive them in the HTTP request because the client uses them).

[lazychaser]

Try this:

DB::transaction(function () use ($id, $input)
{
  $root = FacilitySection::findOrFail($id);
  $root->fill($input->all());
  $root->save();

  foreach ($root->children as $child) $child->delete();

  foreach ($input->get('children', []) as $child)
  {
    FacilitySection::create($child, $root);
  }
});

$input is Request instance.

But this is generally a bad practice since you're loosing your ids on which other resource may depend. see #50

[clapas]

Same result.

homestead=# select * from facility_sections where parent_id = 1;
id | parent_id | _lft | _rgt | facility_id | name | value
---+-----------+------+------+-------------+------+-------
44 |         1 |   12 |   13 |             | Seat | 3 
45 |         1 |   14 |   15 |             | Seat | 4 
46 |         1 |   16 |   17 |             | Seat | 5 
47 |         1 |   18 |   19 |             | Seat | 6 
48 |         1 |   20 |   21 |             | Seat | 7 
42 |         1 |   32 |   33 |             | Seat | 1 
49 |         1 |   22 |   23 |             | Seat | 8 
43 |         1 |   10 |   11 |             | Seat | 2 
(8 rows)

homestead=# select * from facility_sections where id = 1;
id | parent_id | _lft | _rgt | facility_id |   name   | value 
---+-----------+------+------+-------------+----------+-------
1  |           |    1 |   24 |           2 | Numbered |      

[lazychaser]

Please, dump the database before and after operation.

[lazychaser]

Also, after deleting children, try this:

$root->refreshNode();
dd($root);

[clapas]

This is before operation. You have the dump after operation in my last comment. I tried $root->refreshNode() after deleting children, but it made no difference.

homestead=# select * from facility_sections where parent_id = 1;
id | parent_id | _lft | _rgt | facility_id | name | value
---+-----------+------+------+-------------+------+-------
34 |         1 |    2 |    3 |             | Seat | 1
35 |         1 |    4 |    5 |             | Seat | 2
36 |         1 |    6 |    7 |             | Seat | 3
37 |         1 |    8 |    9 |             | Seat | 4
38 |         1 |   10 |   11 |             | Seat | 5
39 |         1 |   12 |   13 |             | Seat | 6
40 |         1 |   14 |   15 |             | Seat | 7
41 |         1 |   16 |   17 |             | Seat | 8
(8 rows) 

homestead=# select * from facility_sections where id = 1;
id | parent_id | _lft | _rgt | facility_id |   name   | value 
---+-----------+------+------+-------------+----------+-------
1  |           |    1 |   18 |           2 | Numbered |      
(1 row)

[lazychaser]

And now just delete the children withoud appending new ones and show me the dump

[clapas]

This is after deleting children without appending the new ones. There are no children:

homestead=# select * from facility_sections where parent_id=1;
 id | parent_id | _lft | _rgt | facility_id |   name   | value 
----+-----------+------+------+-------------+----------+-------
(0 rows)
homestead=# select * from facility_sections where id=1;
 id | parent_id | _lft | _rgt | facility_id |   name   | value 
----+-----------+------+------+-------------+----------+-------
  1 |           |    1 |   10 |           2 | Numbered |       
(1 row)

[lazychaser]

So, something wrong with deletion. _rgt is not right.

Try this for deleting:

while ($child = $node->children()->first()) $child->delete()

[clapas]

I have tried that, but got same results.

[lazychaser]

Thats odd. Maybe transaction has something to do with this?

[clapas]

Tried commenting the transaction lines. Got the same :s