Laravel Nestedset - category tree, problem with updating data. How to fix?

Question

Laravel

The category tree is built using the Kalnoy\Nestedset\NodeTrait package . When the package and migrations are installed, a number of fields are created in the database table: parent_id , _lft and _rgt .

Everything works, but there were difficulties, or some kind of misunderstanding associated with updating the categories.
When creating a new category, it is enough to assign parent_id - the id data of the parent category , and the category is created with the required nesting level.

However, when updating the data, I get an error message,


According to this error message, Nestedset cannot move a node into itself. But in this case, I'm just trying to save the updated data.
Resource controller UPDATE method:

public function update(Request $request, $id)
    {
        $category = Category::find($id);
        $data = $request->all();
         //$data - внесение изменений в данные для последующего сохранения
        $category->update($data);
        return redirect()->route('categories.index')->with('success', 'Категория изменена');
    }

I did not find a solution to the problem in the documentation. Please help the community to resolve this issue. Who has experience and worked with Kalnoy\Nestedset\NodeTrait, where to look, what to fix?

Answer 1

The problem is solved, I will describe the solution.
1. In my case, there was an error in the logic. I tried to save the ID of the category being edited as parent_id, as a result I received the Kalnoy\Nestedset\NodeTrait message stating that the category cannot be nested into itself. An error occurred while copying the category creation form into a data editing template.
2. Simply assigning parent_id - parent category id data, is not enough to build Kalnoy\Nestedset\NodeTrait tree of nested categories. To recalculate the tree, if a parent_id is directly assigned to a new category, it is necessary to run the method:
$category::fixTree();
this method starts the recalculation of the tree based on the parent_id data , fills in the field values ​​in the table_lft and _rgt , on the basis of which the nesting tree is built.