" 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 . 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. View instability vs. model stability If constructed correctly, models can enjoy a fair degree of stability (owing to the stability of the domain model), whereas user interface code usually undergoes frequent and sometimes dramatic change (typically because of usability problems, the need to support growing classes of users, or simply the need to keep the application looking "fresh"). Separating the view from the model makes the model more robust, because the developer is less likely to "break" the model while reworking the view. Old Model Car Attempting to stitch these two worlds together in a hand coded method without architecture is very common, and results in the model object being polluted with knowledge of the interface, and vice-versa. This makes the code very inflexible and difficult to maintain. "

", 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. Model Car Magazine 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. "