Chapter: Model View Controller

The "pure" version

In its simplest and most basic form a project is divided into three components:

• The Model. This is where the essentials of the project reside. All the computation occurs here except for what is necessary for the user interface.
• The Controller. The controller manages everything. It provides the input for the model to process. It tells the view what to display.
• The View. Simply displays what the controller tells it to display.

The Model has no knowledge of the View, and the View knows nothing of the Model. There is absolutely no communication between the Model and the View.

The Controller initiates communication with the Model. It may be sending information to, or getting information from, the Model. Similarly, the Controller initiates communication with the View. Typically the Controller sends items for the View to display.

The same model can coexist with many different views and many different controllers. The model just does not care. The same controller can have several views.

Controllers are aware of their model and their view. Apart from that, the components are unaware of each other.