", view produces a screen listing the shopping cart contents). The view gets its own data from the model (or direct from the data access layer - sometimes there is no domain logic to do) . The model should have no direct knowledge of the view. However, the observer pattern can be used to provide some indirection between model and view, allowing the model to notify interested parties of a change. A view object can register itself with the model and listen for changes but the model itself remains view-agnostic. The controller does not pass domain objects (the model) to the view although it might issue a command telling the view to update itself. The user interface waits for further user interactions, which begins the cycle anew. Heller Model Ship Benefits and liabilities Although widely used, MVC has both advantages and disadvantages compared to other design options, and individual circumstances should be used to choose the most appropriate design. We discuss some of those here. "

" The V/C split less so. Though MVC comes in different flavors, control flow generally works as follows: The user interacts with the user interface in some way (e. g. , user presses a button) A controller contains the input part of the user interface. The controller accesses the model, possibly updating it in a way appropriate to the user's action (e. g. , controller updates user's shopping cart) A view uses the model to generate an appropriate user interface (e. Bad Ship Modelg. , view produces a screen listing the shopping cart contents). "