Learning JavaScript Design Patterns

MVP

Model View Presenter (MVP) is a derivative of the MVC design pattern that focuses on improving presentation logic. It originated at a company named Taligent in the early 1990s while they were working on a model for a C++ CommonPoint environment. While both MVC and MVP target the separation of concerns across multiple components, there are some fundamental differences between them.

For the purposes of this summary, we will focus on the version of MVP most suitable for web-based architectures.

Models, Views, and Presenters

The P in MVP stands for presenter. It’s a component that contains the user-interface business logic for the view. Unlike MVC, invocations from the view are delegated to the presenter, which are decoupled from the view and instead talk to it through an interface. This allows for all kinds of useful things, such as being able to mock views in unit tests (Figure 10-2).

Figure 10-2. MVP pattern

The most common implementation of MVP is one that uses a Passive View (a view which is, for all intents and purposes, “dumb”), containing little to no logic. If MVC and MVP are different, it is because the C and P do different things. In MVP, the P observes models and updates views when models change. The P effectively binds models to views, a responsibility that was previously held by controllers in MVC.

Solicited by a view, presenters perform any work to do with user requests and ...