Source: Practical PHP Patterns: Page Controller, by Giorgio Sironi, July 14, 2010, Web Dev Zone - https://dzone.com/articles/practical-php-patterns/practical-php-patterns-page
Page Controller is a subpattern of the Model-View-Controller one, where every logical page has a correspondent PageController that produces a response dynamically. Usually there are two collaborators that the Controllers calls methods on - a Model and a View. The Model's goal is executing business logic and providing data, while the View's one is to display it, possibly in different formats, and provide ways for interacting with the application to the user (such as forms and links). History
Back in the time of when the web was starting out as a platform to consult remote documents (1990s), a path would have always corresponded to a static HTML document, which would be sent as-is to the client which requested it in the first place.
With the introduction of dynamic pages, a path did not translate to a single response anymore, but to an object capable of producing a response which can change everytime basing on parameters in the request, cookies or session variables. This dynamic generation of web pages is the basis of the Web as we know it today. Implementation
Technically speaking, a Page Controller is an object (in the broader sense of the term, not ony an instance of a class but every kind of item) kept on the server, which is called upon a certain endpoint is the target of a HTTP request.
For example, plain old PHP scripts, which you call with Urls like /index.php, /list.php or /folder/member.php?id=42 are Page Controllers. But what is happening when you see Urls like /node/25645? Obviousy there is no 25645 file stored in the web server filesytem.
In more modern PHP frameworks, like Zend Framework or Symfony, the Page Controllers are not files but classes, a choice which simplifies the management of scope and the parameters passing to them (and also provides the unique possibility of defining multiple action methods). In this environment, Page Controllers are called Action Controllers or simply Actions, but don't be fooled by the name, since we have seen that even a simple PHP script is a Page Controller.
