Hi,
4. It's just a standard foreach so it should be easy:
$ids = array();
foreach($this->order->products as $product){
$ids[]=$product->product_id;
}
echo implode(',',$ids);
5. You can use either that code or directly $this->order. Both would contain the same thing.
The method from the other thread was given because I didn't know the version of that user as he didn't provide it and $this->order is only available in recent versions of HikaShop. So I gave him the solution with $order just to be sure it would work, but the version with $this->order is more efficient so I gave you this one since I know you're using the latest version of HikaShop.
You see: That's why it's important to always provide the version of HikaShop you're using when asking a question, like you did. If everyone would provide the information we ask in the new thread form of the forum, it would make our life easier