Eloquent does not add foreign key from relation - laravel-5

Question

I could not find an answer to my problem and I hope I can describe it properly. I do hope to be able to provide all necessary information.
Bottom line: Why does the relations parent ID not get injected on creating a new database entry through the parent model.
I have an Occasions model which holds a collection of pictures. Within the addPicture ($name, $filepath) method the exception is thrown. As pointed out rhough code-comments
Occasion.php
// namespace + use directives omitted
class Occasion extends Model
{
use Sluggable;
protected $fillable = [ 'name', 'root-folder', 'path' ];
public function sluggable ()
{
return [
'slug' => [
'source' => [ 'root-folder', 'name', ],
],
];
}
public function pictures ()
{
return $this->hasMany(picture::class);
}
public function addPicture ($name, $filepath)
{
$thumbname = $this->getThumbFilename($filepath);
dump($this,$this->pictures()); // dump to check my data
$pic = Picture::create(compact('name', 'thumbname'));
// this line is never reached
$pic->createThumb($filepath);
}
...
}
Picture.php:
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
use Spatie\Glide\GlideImage;
class Picture extends Model
{
protected $fillable = [ 'name', 'thumbname' ];
public function createThumb ($filepath)
{
$this->ppath = storage_path('app') . "/" . $filepath;
$this->tpath = storage_path('app/public/thumbs') . "/" . $this->getfilename($filepath);
GlideImage::create($this->ppath)->modify([ 'w' => 100, 'h' => 100, 'fit' => 'max' ])->save($this->tpath);
$this->save();
}
public function occasion ()
{
return $this->belongsTo(Occasion::class);
}
/* public function slideshow ()
{
return $this->belongsToMany(Slideshow::class);
}*/
private function getfilename ($path)
{
$tmp = array_slice(explode('/', $path), -3);
return str_replace(" ", "-", implode("-", $tmp));
}
}
The result of dump($this->pictures()); shows the relation and the columns used:
HasMany {#206 ▼
#foreignKey: "pictures.occasion_id"
#localKey: "id"
#query: Builder {#205 ▶}
#parent: Occasion {#215 ▶}
#related: Picture {#210 ▶}
}
But I'm getting an error message telling me that my occasion_id (in pictures table) is missing a default value. Looking at the built query the occasion_id is indeed missing. What I can't figure out is why said ID does not get injected as I am creating the new picture instance through an occasion-object.
QueryException
SQLSTATE[HY000]: General error: 1364 Field 'occasion_id' doesn't have a default value (SQL: insert into `pictures` (`name`, `thumbname`, `updated_at`, `created_at`) values (IMG_0015.JPG, 2006-PVanlage-06-IMG_0015.JPG, 2017-09-12 19:34:07, 2017-09-12 19:34:07))
I hope that all necessary information is provided.

Answer 1

First you need to add "occasion_id" to fillable array in App\Picture model. Secondly, you need to create occasion object first, then pass the ID addPicture to create picture object, see below
public Picture extends Model{
public $fillable = ['name', 'filepath', 'occasion_id'];
public function occasion(){
$this->belongsTo(App\Occassion::class);
}
}
public function addPicture ($name, $filepath, $occasion_id)
{
$thumbname = $this->getThumbFilename($filepath);
dump($this,$this->pictures()); // dump to check my data
$pic = Picture::create(compact('name', 'thumbname', 'occasion_id'));
// this line is never reached
$pic->createThumb($filepath);
}
There's a smarter way to do this, but this should work.