Modify a custom attribute of an Eloquent Model

Question

I have a model which contain a custom attribute

class Test extends Model
{
    protected $appends = ['counter'];
    public function getCounterAttribute()
    {
        return 1;
    }
}

I need to change the value of the custom attribute, like:

$tests = Test::all();
foreach ($tests AS $test) {
    $test->counter = $test->counter + 100;
}

This does not work, which is the correct way to do it?

Solution

The problem is that your accessor returns always 1

public function getCounterAttribute()
{
    return 1;
}

Your loop sets correctly the counter attribute (inspectable via $model->attributes['counter']). However, when you call $test->counter its value is resolved via the getCounterAttribute() method, that returns always 1.

Update your getCounterAttribute() to something like this:

public function getCounterAttribute()
{
    return isset($this->attributes['counter']) ? $this->attributes['counter'] : 1;
}

this way, you are saying: "if the counter attribute is set, return it. Otherwise, return 1".