In order to use model attribute you need to save (create) the model first. Why?

I have a TOTAL AMOUNT field which is updated (depends on) when I add a new product to a list of products (relation hasMany) in my model.

This is how I update my total amount field:

public function filterFields($fields, $context = null)
{
        $fields->total->value = $this->total;
}

public function getTotalAttribute()
{
        $totale = 0;
        foreach ($this->orderitems as $orderitem => $value) {
            $totale += $value->total;
        }

        return $totale;
}

So simply, until I save the new object, I cannot use the models attributes $this->orderitems, $this->total etc.

Last updated 4 years ago

Until the parent model is saved, its relations are deferred... so use the withDeferred() method to access the deferred relations:

public function getTotalAttribute()
{
    $totale = 0;
    $sessionKey = post('_session_key');
    if ($sessionKey) {
        foreach ($this->orderitems()->withDeferred($sessionKey)->get() as $orderitem => $value) {
            $totale += $value->total;
        }
    }

    return $totale;
}