The toArray method only returns the first level of nesting?

Question

Laravel

What am I doing wrong?
In the model:

class DocumentType extends Model
{
    protected $fillable = [
        'id',
        'code',
        'name',
        'active',
    ];

    public $childs;

Calling:
print_r(DocumentType::getTree());
Result:

Illuminate\Database\Eloquent\Collection Object
(
    [items:protected] => Array
        (
            [0] => App\Models\Docflow\DocumentType Object
                (
                    [fillable:protected] => Array
                        (
                            [0] => id
                            [1] => code
                            [2] => name
                            [3] => active
                        )

                    [childs] => Illuminate\Support\Collection Object
                        (
                            [items:protected] => Array
                                (
                                    [7] => App\Models\Docflow\DocumentType Object  .............

If so:
print_r(DocumentType::foo()->toArray());
return result:

Array
(
    [0] => Array
        (
            [id] => 6
            [parent_id] => 2
            [code] => 
            [name] => Приказ на переводе на другую должность
            [active] => 1
        )

Why is the childs property not present in the resulting array and why is it not converted to an array?

Answer 1

Because what is serialized in $this->attributes and in $this->relations * . About the fact that you added some property to the class, Laravel does not know anything and whether you want to serialize it or not - too. In addition to the source code, it is also useful to read the documentation .
PS children, not childs.
* in fact, the logic is more complicated.