Class-based views

In Chapter 1 and at the start of this chapter -- in listing 2-1 -- you saw how to define a Django url and make it operate with a Django template without the need of a view method. This was possible due to the django.views.generic.TemplateView class, which is called a class-based view.

Unlike Django view methods backed by standard Python methods that use a Django HttpRequest input parameter and output a Django HttpResponse, class-based views offer their functionality through full-fledged Python classes. This in turn allows Django views to operate with object oriented programming (OOP) principles (e.g. encapsulation, polymorphism and inheritance) leading to greater re-usability and shorter implementation times.

Although Django class-based views represent a more powerful approach to create Django views, they are simply an alternative to the view methods you've used up to this point. If you want to quickly execute business logic on Django requests you can keep using view methods, but for more demanding view requirements (e.g. form processing, boilerplate model queries) class-based views can save you considerable time.

Built-in class-based views

The functionality provided by the django.views.generic.TemplateView class-based view is real a time saver. While it would have been possible to configure a url to execute on an empty view method and then send control to a template, the TemplateView class allows this process to be done in one line.

In addition to the TemplateView class-based view, Django offers many other built-in class-based views to shorten the creation process for common Django view operations using OOP-like principles. Table 2-11 illustrates Django's built-in classes for views.

Table 2-11. Built-in classes for views

Class Description
django.views.generic.View Parent class of all class-based views, providing core functionality.
django.views.generic.TemplateView Allows a url to return the contents of a template, without the need of a view.
django.views.generic.RedirectView Allows a url to perform a redirect, without the need of a view.
Allows a view to return date-based object results, without the need to explicitly perform Django model queries.
Allows a view to execute Create-Read-Update-Delete (CRUD) operations , without the need to explicitly perform Django model queries.

In the upcoming and final section of this chapter, I'll explain the classes in the top-half of table 2-11 so you can gain a better understanding of the structure and execution process of Django class-based views. The class-based views in bottom half of table 2-11 that involve Django models are described in a separate chapter on Django class-based views models.