Model-View-Controller (MVC) is an architectural design pattern first written about and implemented by in 1978. Trygve developed this pattern during the year he spent working with Xerox PARC on a small talk application.
According to Trygve, “The essential purpose of MVC is to bridge the gap between the human user's mental model and the digital model that exists in the computer. The ideal MVC solution supports the user illusion of seeing and manipulating the domain information directly. The structure is useful if the user needs to see the same model element simultaneously in different contexts and/or from different viewpoints.” Trygve Reenskaug on MVC
The MVC pattern is composed of 3 core components.
Model
View
Controller
The Model component referenced in the MVC pattern pertains to the encapsulation of core application data and functionality. The primary goal of the model is to maintain its independence from the View and Controller components which together form the user interface of the application.
The View component retrieves data from the Model and displays it to the user. The View component represents the output of the application to the user. Traditionally the View has read-only access to the Model component because it should not change the Model’s data.
The Controller component receives and translates input to requests on the Model or View components. The Controller is responsible for requesting methods on the model that can change the state of the model.
The primary benefit to using MVC as an architectural pattern in a project compared to other patterns is flexibility. The flexibility of MVC is due to the distinct separation of concerns it establishes with three distinct components. Because of the distinct separation between the components interaction is limited through the use of interfaces instead of classes. This allows each of the components to be hot swappable when the needs of the application change or needs of availability change.
MVC can easily be applied to C# and the .Net Framework. In fact, Microsoft created a MVC project template that will allow new project of this type to be created with the standard MVC structure in place before any coding begins. The project also creates folders for the three key components along with default Model, View and Controller classed added to the project.
Personally I think that MVC is a great pattern in regards to dealing with web applications because they could be viewed from a myriad of devices. Examples of devices include: standard web browsers, text only web browsers, mobile phones, smart phones, IPads, IPhones just to get started.
Due to the potentially increasing accessibility needs and the ability for components to be hot swappable is a perfect fit because the core functionality of the application can be retained and the View component can be altered based on the client’s environment and the View component could be swapped out based on the calling device so that the display is targeted to that specific device.
