einundzwanzig-portal/app/Models/Meetup.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Spatie\Image\Manipulations;
use Spatie\MediaLibrary\HasMedia;
use Spatie\MediaLibrary\InteractsWithMedia;
use Spatie\MediaLibrary\MediaCollections\Models\Media;
use Spatie\Sluggable\HasSlug;
use Spatie\Sluggable\SlugOptions;

class Meetup extends Model implements HasMedia
{
    use HasFactory;
    use InteractsWithMedia;
    use HasSlug;

    /**
     * The attributes that aren't mass assignable.
     * @var array
     */
    protected $guarded = [];
    /**
     * The attributes that should be cast to native types.
     * @var array
     */
    protected $casts = [
        'id'      => 'integer',
        'city_id' => 'integer',
    ];

    protected static function booted()
    {
        static::creating(function ($model) {
            if (!$model->created_by) {
                $model->created_by = auth()->id();
            }
        });
    }

    public function getSlugOptions(): SlugOptions
    {
        return SlugOptions::create()
                          ->generateSlugsFrom(['name'])
                          ->saveSlugsTo('slug')
                          ->usingLanguage('de');
    }

    public function registerMediaConversions(Media $media = null): void
    {
        $this
            ->addMediaConversion('preview')
            ->fit(Manipulations::FIT_CROP, 300, 300)
            ->nonQueued();
        $this->addMediaConversion('thumb')
             ->fit(Manipulations::FIT_CROP, 130, 130)
             ->width(130)
             ->height(130);
    }

    public function registerMediaCollections(): void
    {
        $this->addMediaCollection('logo')
             ->singleFile()
             ->useFallbackUrl(asset('img/einundzwanzig-cover-lesestunde.png'));
    }

    public function createdBy(): BelongsTo
    {
        return $this->belongsTo(User::class, 'created_by');
    }

    public function city(): BelongsTo
    {
        return $this->belongsTo(City::class);
    }

    public function meetupEvents(): HasMany
    {
        return $this->hasMany(MeetupEvent::class);
    }
}