Book Image

Mastering Object-oriented Python

By : Steven F. Lott, Steven F. Lott
Book Image

Mastering Object-oriented Python

By: Steven F. Lott, Steven F. Lott

Overview of this book

Table of Contents (26 chapters)
Mastering Object-oriented Python
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Some Preliminaries
Index

Using decorators for security


Software is filled with cross-cutting concerns, aspects that need to be implemented consistently even if they're in separate class hierarchies. It's often a mistake to try and impose a class hierarchy around a cross-cutting concern. We've looked at a few examples, such as logging and auditing.

We can't reasonably demand that every class that might need to write to the log also be a subclass of some loggable superclass. We can design a loggable mixin or a loggable decorator. These don't interfere with the proper inheritance hierarchy that we need to design to make polymorphism work correctly.

Some important cross-cutting concerns revolve around security. Within a web application, there are two sides to the security question as follows:

  • Authentication: Do we know who's making the request?

  • Authorization: Is the authenticated user allowed to make the request?

Some web frameworks allow us to decorate our request handlers with security requirements. The Django framework...