ModelViewController

Model-view-controller is a software architectural pattern used for implementing user interfaces by separating an application into three interconnected components: the model, the view, and the controller. The model manages the underlying data and business logic. The view renders the user interface and presents data to the user. The controller interprets user input, manipulates the model, and updates the view accordingly.

In operation, the user interacts with the view, the controller handles input events, updates the model, and the view updates to reflect changes. The separation of concerns aims to improve maintainability, testability, and scalability by isolating data handling from presentation and user interaction.

History: The pattern was formulated by Trygve Reenskaug in the late 1970s for Smalltalk at Xerox PARC and has since been adapted by many platforms and frameworks. Over time, various interpretations of MVC have emerged, and several related patterns have appeared, such as Model-View-Presenter and Model-View-ViewModel.

Implementation notes: In some ecosystems, the controller handles most presentation logic, leading to the Massive View Controller problem in mobile development. In web frameworks, MVC can be realized with server-side controllers handling requests and rendering views, or with client-side controllers managing UI state. Data binding and dependency injection are often used to improve testability and reduce boilerplate.

Related concepts include MVP and MVVM, which adjust the distribution of responsibilities to address testability and separation of concerns. The MVC pattern remains foundational in many languages and frameworks, but its concrete division of labor varies across platforms.