CakePHP's Approach to the MVC Architecture

Readers who already know Ruby on Rails may find CakePHP very similar to it. For one thing, Cake is based on an MVC-like architecture that is both powerful and easy to grasp: controllers, models and views guarantee a strict but natural separation of business logic from data and presentation layers.

Controllers contain the logic of your application. Each controller can offer different functionality; controllers retrieve and modify data by accessing database tables through models; and they register variables and objects, which can be used in views.

Models are active representations of database tables: they can connect to your database, query it (if instructed to do so by a controller) and save data to the database. It is important to note that in order to correctly apply the MVC architecture, there must be no interaction between models and views: all the logic is handled by controllers.

Views can be described as template files that present their content to the user: variables, arrays and objects that are used in views are registered through a controller. Views should not contain complex business logic; only the elementary control structures necessary to perform particular operations, such as the iteration of collected data through a foreach construct, should be contained within a view.

This architecture can greatly improve the maintainability and the organization of your site's code:

• It separates business logic from presentation and data retrieval.
• A site is divided into logical sections, each governed by a particular controller.
• When testing and debugging an application, any developer accustomed to CakePHP's structure will be able to locate and correct errors without knowing all of the details of the code.

Controllers, models and views are stored in pre-defined directories within CakePHP's directory structure. Here's the directory structure that's used:

• app/
  • config/
  • controllers/
  • models/
  • plugins/
  • tmp/
  • vendors/
  • views/
  • webroot/
• cake/
  • config/
  • docs/
  • libs/
• vendors/

This directory scheme must be preserved, as it is essential if the framework itself is to work. Cake, like Rails, believes in the importance of convention over configuration: in order to deploy an application, rather than modify dozens of different configuration files, it's important only to place everything in its proper place; then, you can let the framework do the rest.

Although this may seem worrisome for some developers, it's a good compromise that can really accelerate the development process.