View source for Model-view-controller

'''Model–view–controller''' ('''MVC''') is a [[software]] [[architectural pattern]] for implementing [[User interface|user interfaces]].

== Description ==

MVC divides a given software application into three interconnected parts, so as to separate internal representations of information from the ways that information is presented to or accepted from the user.

As with other software patterns, MVC expresses the "core of the solution" to a problem while allowing it to be adapted for each system.  Particular MVC architectures can vary significantly from the tradition model.

== Components ==

The traditional MVC has three components:

* The '''model''' describes the behavior of the application in terms of its problem domain, independent of the user interface.
** The model directly manages the data, logic and rules of the application
* The '''view''' generates output for the user
** Multiple views of the same information are possible
* The '''controller''' accepts input and converts it to commands for the model or view.

== Interactions ==

In addition to dividing the application into three kinds of components, the model–view–controller design defines the interactions between them.

A controller can send commands to the model to update the model's state (e.g., editing a document). It can also send commands to its associated view to change the view's presentation of the model (e.g., by scrolling through a document).

A model stores data that is retrieved by the controller and displayed in the view. Whenever there is a change to the data it is updated by the controller.

A view requests information from the model that it uses to generate an output representation to the user.

== MVC in web applications ==

Although originally developed for desktop computing, model–view–controller has been widely adopted as an architecture for [[Web application|web applications]] in major [[Programming language|programming languages]].

== Frameworks ==

Several commercial and noncommercial [[Web application framework|web application frameworks]] have been created that enforce the pattern. 

These frameworks vary in their interpretations, mainly in the way that the MVC responsibilities are divided between the client and server.

== History ==

Early web MVC frameworks took a thin client approach that placed almost the entire model, view and controller logic on the [[Server (computing)|server]]. 

In this approach, the [[Client (computing)|client]] sends either [[Hyperlink request|hyperlink requests]] or [[Web form request|form requests with user data]] to the controller, and then receives a complete and updated [[web page]] (or other document) from the view; the model exists entirely on the server.

As [[client-side technologies]] have matured, frameworks such as [[AngularJS]], Ember.js, JavaScriptMVC and [[Backbone.js]] have been created that allow the MVC components to [[Client-side scripting|execute partly on the client]].

== Ajax ==

See also [[Ajax (programming)]], which is commonly used with MVC-base [[Web application|web applications]].

== See also ==

* [[Ajax (programming)]]
* [[AngularJS]]
* [[Architectural pattern]]
* [[Backbone.js]]
* [[Computer science]]
* [[Design pattern]]
* [[Model]]
* [[Observer pattern]]
* [[Server (computing)]]
* [[Software design pattern]]
* [[Software development]]
* [[Software development process]]
* [[Web application]]
* [[Web application framework]]

== External links ==

* [https://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller Model–view–controller] @ Wikipedia