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

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.

Answer 3

The problem is the get is returning a collection of stdObject
Instead of adding the new field to the result of your query, modify the model of what you are returning.
So, assuming you have a PromotionBanner.php model file in your app directory, edit it and then add these 2 blocks of code:
protected $appends = array('promotionImage');
here you just added the custom field. Now you tell the model how to fill it:
public function getPromotionImageAttribute() {
return (url('home/image/banner/'.$this->promotion_banner_id));
}
Now, you get your banners through your model:
static function m_get_promotion_banner(){
return \App\PromotionBanner::where('promotion_active','1')->get();
}
Now you can access your promotionImage propierty in your result
P.D:
In the case you are NOT using a model... Well, just create the file app\PromotionImage.php:
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class PromotionImage extends Model
{
protected $appends = array('imageAttribute');
protected $table = 'promotion_banner';
public function getPromotionImageAttribute() {
return (url('home/image/banner/'.$this->promotion_banner_id));
}
/**
* The attributes that are mass assignable.
*
* #var array
*/
protected $fillable = [
'promotion_banner_id','promotion_link','about_promotion','promotion_active'
];

Answer 4

just improving, in case you need to pass data inside the query
$url = 'home/image/banner/';
$query = $query->map(function ($object) use ($url) {
// Add the new property
$object->promotion_image = URL::to( $url . $object->promotion_banner_id);
// Return the new object
return $object;
});

Answer 5

I've been struggling with this all evening, and I'm still not sure what my problem is.
I've used ->get() to actually execute the query, and I've tried by ->toArray() and ->jsonserialize() on the data and it didn't fix the problem.
In the end, the work-around I found was this:
$task = Tasks::where("user_id", $userId)->first()->toArray();
$task = json_decode(json_encode($task), true);
$task["foo"] = "bar";
Using json_encode and then json_decode on it again freed it up from whatever was keeping me from editing it.
That's a hacky work-around at best, but if anyone else just needs to push past this problem and get on with their work, this might solve the problem for you.