Bootable Sluggable Trait

sluggable.php

// https://dotdev.co/creating-unique-title-slugs-with-laravel/
// https://andy-carter.com/blog/using-laravel-s-eloquent-traits

<?php

namespace App\Traits;

use Illuminate\Support\Str;

trait Sluggable
{

    public static function bootSluggable()
    {
        static::saving(function ($model) {
            $model->slug = $model->createSlug(get_class($model), $model->title);
        });

        static::updating(function ($model) {
            $model->slug = $model->createSlug(get_class($model), $model->title, $model->id);
        });
    }


    /**
     * @param $title
     * @param int $id
     * @return string
     * @throws \Exception
     */
    public function createSlug($className, $title, $id = 0)
    {
        // Normalize the title
        $slug = Str::slug($title);

        // Get any that could possibly be related.
        // This cuts the queries down by doing it once.
        $allSlugs = $this->getRelatedSlugs($className, $slug, $id);
        // If we haven't used it before then we are all good.
        if (!$allSlugs->contains('slug', $slug)) {
            return $slug;
        }
        // Just append numbers like a savage until we find not used.
        for ($i = 1; $i <= 10; $i++) {
            $newSlug = $slug . '-' . $i;
            if (!$allSlugs->contains('slug', $newSlug)) {
                return $newSlug;
            }
        }
        throw new \Exception('Can not create a unique slug');
    }
    protected function getRelatedSlugs($className, $slug, $id = 0)
    {
        return $className::select('slug')->where('slug', 'like', $slug . '%')
            ->where('id', '<>', $id)
            ->get();
    }
}