openstamanager/src/Traits/HierarchyTrait.php

<?php
/*
 * OpenSTAManager: il software gestionale open source per l'assistenza tecnica e la fatturazione
 * Copyright (C) DevCode s.r.l.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 */

namespace Traits;

trait HierarchyTrait
{
    public function children()
    {
        return $this->hasMany(self::class, self::$parent_identifier);
    }

    public function parent()
    {
        return $this->belongsTo(self::class, self::$parent_identifier);
    }

    public function allParents()
    {
        return $this->parent()->with('allParents');
    }

    public function allChildren()
    {
        return $this->children()->with('allChildren');
    }

    public static function getHierarchy()
    {
        return self::with('allChildren')
            ->whereNull(self::$parent_identifier)
            ->get();
    }
}