In MVC pattern, there is a separation between model and its views. In pure pattern, a model interacts with its views through a controller(s).

WPDK implements this pattern by the use of two fundamental classes, that a developer can (have to) specialize extending them with its own needs: WPDKView, and WPDKViewController classes.

WPDKViewController class exposes methods and properties to manage the whole HTML display into the work area of WordPress Administration Screen. Upon request, it provides a view that can be displayed or interacted with. Often, this view is the root view for a more complex hierarchy of views, implemented by specialized instances of WPDKView class. The view controller acts as the central coordinating agent for the view hierarchy, handling exchanges between the views and any relevant controller or data objects.

This is the typical hierarchy handled by a specialized instance of WPDKViewController class:

header with icon and title + optional button add = an instance of WPDKHeaderView class.
one or more views, that can be specialized instances of WPDKView class.

Overriding display method in specialized WPDKViewController class allows a developer to set a custom content for its instances. The same for WPDKView class.

Why using this complexity? For WPDKView class, to encapsulate specialized behaviours that can be reusable anywhere, simply creating a new instance of the specialized WPDKView class that implements them. For WPDKViewController class, to centralize handling of low-level HTML into the whole work area of WordPress Administration Screen; you don't need to create everytime by hand all the <div></div> parts of your HTML view into the work area: simply set your own specific HTML content overriding display method, and then call it, if necessary.

To see how all this theory turns to action, go to WPDK How-To and get the source code that use this pattern.