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Drupal 9.3.0 came with a new feature called entity bundle classes. This allows more control of entity bundles within Drupal and provides a number of benefits over the previous mechanism of using hooks to control everything.

Drupal makes extensive use of entities to manage content and configuration. User details, pages of content and taxonomy terms just a few of the things that are represented in a Drupal site as content entities. Different types of similar configuration are called configuration entities, which would include things like text format settings or even date formats.

Content entities are normally fieldable, and in the case of content types and taxonomy terms Drupal allows users to generate their own variants. These different variants of entities are called bundles. Entities define the types of objects found in a Drupal site, bundles represent the different sub-types of these entities.

SOLID is a set of object oriented design principles aimed at making code more maintainable and flexible. They were coined by Robert "Uncle Bob" Martin in the year 2000 in his paper Design Principles and Design Patterns. The SOLID principles apply to any object oriented language, but I'm going to concentrate on what they mean in a Python application in this post.

I originally wrote about SOLID principles with PHP as the basis of the article, but as the lessons here can be easily applied to any object oriented language I thought that I would re-write it with Python in mind. If you are familiar with only PHP or Python then this will be a good learning resource on learning the other side.

I have been learning Python recently, and whilst I'm familiar with PHP and other C-like languages, Python has been a bit of a challenge to get used to due to the different syntax. This is especially the case with objects as although Python is object oriented there are a couple of gotchas when creating custom objects. This article sets out how to use classes and objects, but I will assume that you have a basic understanding of object oriented programming in other languages.

A Data Transfer Object (DTO) is a way of taking data out of a database or API and present it in a unified way across your application. As a design pattern this has uses in standardising how a particular bit of data is passed around, without having to resort to using arrays to accomplish the same job.

I was doing some work with PHP's PDO library the other day when I noticed that I could fetch data out of a database using the fetchAll() method with the PDO::FETCH_CLASS flag. This flag automatically returns the data in an object. This got me thinking more about how this worked, but I couldn't find many articles talking about this. Hence this post.

Setting Things Up

Let's take a class called SpecialText that will store an ID and some text, along with a __toString() method to allow the printing of those values. We will use this class throughout this post to store data from the database.