How to update Laravel Eloquent column cast to collection

Question

I am using Laravel 10.

I utilize the conversion of JSON columns in the following way:

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Item extends Model
{
  protected $casts = [
    'meta' => 'collection', // here
  ];
}

For example, when trying to update a value in a collection directly:

$model->meta->put('test', 100);
$model->save();

No response.

When I assign the variable as is, it works fine.

$model->meta = ['test' => 100];
$model->save();

But what if I only need to update/add a single element?

I found the following workaround, but is this expected behavior?

$meta = $model->meta;
$meta->put('test', 100);
$model->meta = $meta;
$model->save();

In this case, only direct assignment seems to work, and casting the collection doesn't seem to support any of its write capabilities.

Answer 1

Try to convert it to a collection AsCollection

use Illuminate\Database\Eloquent\Casts\AsCollection;


protected $casts = [
  'meta' => AsCollection::class,
  ...
];

Answer 2

Solution (Laravel 8.28 or higher)

Need to use Illuminate\Database\ Eloquent\Casts\AsCollection instead of 'collection'.

In the $casts array, you can define the type of each key. Laravel automatically handles the conversion by specifying the type's class (when necessary). That's why specifically using AsCollection::class is required.

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Casts\AsCollection;

class Item extends Model
{
  protected $casts = [
    'meta' => AsCollection::class, // automatically convert value of 'meta' to Collection::class
  ];
}

More information

• Property Transformation (Conversion List) - Laravel Documentation (10.x)
• Array, Object, and Collection Conversions - Laravel Documentation (10.x)
• Laravel 8 Added New Transformations - Laravel News
• AsCollection::class - Laravel API Documentation

---

Solution (Laravel 7.x or lower)

AsCollection Available by default in Laravel 8.x or higher. If you need the set functionality from older versions, you'll need to create a custom cast yourself.

Or you can also use 'array'Actor:

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Item extends Model
{
  protected $casts = [
    'meta' => 'array', // automatically convert value of 'meta' to array
  ];
}

More information

• How to perform custom conversions - Laravel Documentation (7.x)