The view and controller

The view and the controller are very close cousins. The controller makes the data available for display to the view and the view generates the pages that trigger events, which sends data to the controller.

In Yii, a view file belongs to the controller class that rendered it. This way, inside a view script, we can access the controller instance by simply referring to $this. This implementation makes the view and controller very intimate. Thankfully, all of these details are handled for us by Yii, so we can focus on coding the specific application.

There is also a lot more to Yii controllers than just calling the model and rendering views. Controllers can manage services to provide sophisticated pre- and post-processing on requests, implement basic access control rules to limit access to certain actions, manage application-wide layout and nested layout file rendering, manage pagination of data, and many other behind-the-scenes services. Again, we have Yii to thank for not needing to get our hands dirty with these messy details.

There is a lot to Yii. The best way to explore all its beauty is to start using it. Now that we have some of the basic ideas and terminology under our belt, we are in a great position to do just that. In the next chapter, we will go through the simple Yii installation process, and then build a working application to better illustrate these ideas.