Indirect modification of overloaded element of Illuminate\Support\Collection has no effect

Question

im quite new in laravel framework, and im from codeigniter.

I would like to add new key and value from database

static function m_get_promotion_banner(){
    $query = DB::table("promotion_banner")
        ->select('promotion_banner_id','promotion_link','about_promotion')
        ->where('promotion_active','1')
        ->get();
    if($query != null){
        foreach ($query as $key => $row){
            $query[$key]['promotion_image'] = URL::to('home/image/banner/'.$row['promotion_banner_id']);
        }
    }
    return $query;
}

that code was just changed from codeigniter to laravel, since in codeigniter there are no problem in passing a new key and value in foreach statement

but when i tried it in laravel i got this following error :

Indirect modification of overloaded element of Illuminate\Support\Collection has no effect

at HandleExceptions->handleError(8, 'Indirect modification of overloaded element of Illuminate\Support\Collection has no effect', 'C:\xampp\htdocs\laravel-site\application\app\models\main\Main_home_m.php', 653, array('query' => object(Collection), 'row' => array('promotion_banner_id' => 1, 'promotion_link' => 'http://localhost/deal/home/voucher', 'about_promotion' => ''), 'key' => 0))

please guide me how to fix this

thank you (:

Answer 1

The result of a Laravel query will always be a Collection. To add a property to all the objects in this collection, you can use the map function.

$query = $query->map(function ($object) {

    // Add the new property
    $object->promotion_image = URL::to('home/image/banner/' . $object->promotion_banner_id);

    // Return the new object
    return $object;

});

Also, you can get and set the properties using actual object properties and not array keys. This makes the code much more readable in my opinion.

Answer 2

For others who needs a solution you can use jsonserialize method to modify the collection. Such as:

$data = $data->jsonserialize();
//do your changes here now.