Ruby on Rails® Bible

Chapter 5. View: In Depth

So far you've read about the model and controller layers of a Rails application. There is one layer remaining to discuss in an MVC (Model-View-Controller) application. That is the view layer. The view layer is the layer that presents your application to the end users. Although this layer shouldn't handle any of your application's business or processing logic, it is at least as important to the success of an application as the model and controller layers. You may have the greatest technology in the world, but if you can't present it in a way that is easy to use and appealing, ultimately your technology will go unused.

Rails offers you a number of tools that will assist you in creating a welldesigned, maintainable and rich view layer.

ActionView

The Rails component that manages the view layer of your application is called ActionView. ActionView is what provides you with most of the technologies that you will read about in the remainder of this chapter. These technologies include the following:

• Embedded Ruby (ERb)

• Layout templates

• Partial templates

• Helper methods

In a Rails application, your view templates are placed into a directory under the app directory called views. Within the views directory, each controller has its own subdirectory for views relating to actions in that controller. In addition, there is a special controller called layouts which contains the common layouts used throughout the application. You can create your own subdirectories for other shared ...