Book Image

Django Design Patterns and Best Practices - Second Edition

By : Arun Ravindran
Book Image

Django Design Patterns and Best Practices - Second Edition

By: Arun Ravindran

Overview of this book

Building secure and maintainable web applications requires comprehensive knowledge. The second edition of this book not only sheds light on Django, but also encapsulates years of experience in the form of design patterns and best practices. Rather than sticking to GoF design patterns, the book looks at higher-level patterns. Using the latest version of Django and Python, you’ll learn about Channels and asyncio while building a solid conceptual background. The book compares design choices to help you make everyday decisions faster in a rapidly changing environment. You’ll first learn about various architectural patterns, many of which are used to build Django. You’ll start with building a fun superhero project by gathering the requirements, creating mockups, and setting up the project. Through project-guided examples, you’ll explore the Model, View, templates, workflows, and code reusability techniques. In addition to this, you’ll learn practical Python coding techniques in Django that’ll enable you to tackle problems related to complex topics such as legacy coding, data modeling, and code reusability. You’ll discover API design principles and best practices, and understand the need for asynchronous workflows. During this journey, you’ll study popular Python code testing techniques in Django, various web security threats and their countermeasures, and the monitoring and performance of your application.
Table of Contents (21 chapters)
Title Page
Copyright and Credits
PacktPub.com
Contributors
Preface
Index

Retrieval patterns


This section contains design patterns that deal with accessing model properties or performing queries on them. These Retrieval patterns can help you design better ways to access frequently needed information.

Pattern — property field

Problem: Models have derived attributes that are implemented as methods. However, these attributes should not be persisted to the database.

Solution: Use the property decorator on such methods.

Problem details

Model fields store per-instance attributes, such as first name, last name, birthday, and so on. They are also stored in the database. However, we also need to access some derived attributes, such as full name or age.

They can be easily calculated from the database fields, hence need not be stored separately. In some cases, they can just be a conditional check such as eligibility for offers based on age, membership points, and active status.

A straightforward way to implement this is to define functions, such as get_age similar to the following...