更新购物车Laravel

Question

I'm having a problem trying to update the total quantity of items which are in my shopping cart. The problem that I'm having is when I update the quantity of an item, it takes that quantity as the total quantity. How can I sum the quantities of my items in the shopping cart? And then get the total quantity.

This is my controller

public function cartUpdate(Request $request, $id) {
        $oldCart = Session::has('cart') ? Session::get('cart') : null;
        $cart = new Cart($oldCart);
        $quantity = $request->quantity;
        $product = Product::find($id);


        $cart->updateItem($product, $id, $quantity);

        Session::put('cart', $cart);

        return response()->json(['success' => true]);

}

My cart model

public $items = null;
public $totalQty = 0;
public $totalPrice = 0;

public function __construct($oldCart)
{
    if ($oldCart)
    {
        $this->items = $oldCart->items;
        $this->totalQty = $oldCart->totalQty;
        $this->totalPrice = $oldCart->totalPrice;
    }
}

public function updateItem($item, $id, $quantity) {
        $this->items[$id]['qty'] = $quantity;
        $this->items[$id]['price'] = $quantity * $item->price;
        $this->totalQty = $this->items[$id]['qty'];
        $this->totalPrice = $this->totalQty * $item->price;
}

Answer 1

If somebody needs the code. I did it. This is going to work when you need to update your items quantity

public function updateItem($item, $id, $quantity) {
    $this->items[$id]['qty'] = $quantity;
    $this->items[$id]['price'] = $quantity * $item->price;

    $this->totalQty = 0;
    foreach($this->items as $element) {
        $this->totalQty += $element['qty'];
        $this->totalPrice = $this->totalQty * $item->price;
    }
}