I develop an shopping application. This is first time i develop such an application. In a point i am a little confused so maybe someone here to help me. I have an UITableView that i display the products and there will be a basket that user put the product that he wants to buy. I want to create an object(e.g CartManager and it will be singleton) that object will hold the products added and the count etc. My question is that lets say the user added two or three different products in basket. At that point should i use Delegate or NSNotification to inform the ViewControllers that display products ? I hope i could describe my question well.