Pony.fm/app/Traits/SlugTrait.php

<?php

/**
 * Pony.fm - A community for pony fan music.
 * Copyright (C) 2015 Feld0
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

namespace App\Traits;

use Illuminate\Support\Str;

trait SlugTrait
{
    public function setTitleAttribute($value)
    {
        $this->slug = self::makeNonemptySlug($value);
        $this->attributes['title'] = $value;
    }

    private static function makeNonemptySlug($title) {
        $slug = Str::slug($title);
        if ($slug === '') {
            $slug = '-';
        }
        return $slug;
    }
}