Entropy Wins

I’m happy to announce a brand new blog dedicated to MediaWiki and all things enterprise wiki related.

Half a year ago I launched Professional Wiki together with Karsten Hoffmeyer. Professional Wiki is, as the name suggests, a company providing professional wiki services. We help companies create and manage wikis, we provide training and support and we offer fully managed wiki hosting.

Today we…

It’s possible to turn an application into a framework and build additional applications on top of it. What could possibly go wrong? In this post we look at different usage styles of frameworks and why building an application on top of another one comes with some significant challenges.

Decoupled web application

In your typical web application, the code handles a request and returns a response.…

Readable Functions: Guard Clause

Guard Clauses are one of my favorite little tricks that allow simplifying code. A guard clauses is an if statement with a return in it. Consider the following code:

function doThing() { var $thing = 'default'; if (someCondition()) { $thing = 'special case'; } return $thing; }

Using a Guard Clause we can simplify it to:

function doThing() { if…

The best books I read in 2018

In 2018 I read more books than ever before. Here are some of my recommendations and thoughts.

The 34 books I read in 2018

I read 21 fiction books and 13 non-fiction ones. The fiction books where all either hard science fiction or pleb science fiction while the non-fiction ones where mostly about psychology or finance.

Top 2018 fiction book

The price for 2018 best fiction book that I…

Readable Functions: Do One Thing

Several tricks and heuristics that I apply to write easy to understand functions keep coming up when I look at other people their code. This post outlines the second key principle. The first principle is Minimize State. Following posts will contain specific tips and tricks, often building on these two principles.

Do One Thing

Often functions become less readable because they are doing multiple…

Lately there has been a lot of hype around the typed properties that PHP 7.4 will bring. In this post I outline why typed properties are not as big of a game changer as some people seem to think and how they can lead to shitty code. I start by a short introduction to what typed properties are.

What Are Typed Properties

As of version 7.3, PHP supports types for function parametersand for function…

Readable Functions: Minimize State

Several tricks and heuristics that I apply to write easy to understand functions keep coming up when I look at other peoples code. In this post I share the first of two key principles to writing readable functions. Follow up posts will contain the second key principle and specific tricks, often building on these general principles.

What makes functional programmingso powerful? Why do developers…

Clean Architecture + Bounded Contexts diagram

I’m happy to release a two Clean Architecture + Bounded Contexts diagrams into the public domain (CC0 1.0).

I created these diagrams for Wikimedia Deutchland with the help of Jan Dittrich, Charlie Kritschmar and Hanna Petruschat. They represent the architecture of our fundraising codebase. I explain the rules of this architecture in my post Clean Architecture + Bounded Contexts. The new diagrams…

Base Libraries Should be Stable

In this post I go over the principles that govern package (library) design and one specific issue I have come across several times.

Robert C Martin has proposed six Package Principles. Personally I find the (linked) description on Wikipedia rather confusing, especially if you do not already understand the principles. Here is my take on library design using short and simple sentences:

Libraries…

Clean Architecture + Bounded Contexts

In this follow-up to Implementing the Clean Architecture I introduce you to a combination of The Clean Architecture and the strategic DDD pattern known as Bounded Contexts.

At Wikimedia Deutschlandwe use this combination of The Clean Architecture and Bounded Contexts for our fundraising applications. In this post I describe the structure we have and the architectural rules we follow in the…

Bounded Contexts in the Wikimedia Fundraising Software

In this follow-up to rewriting the Wikimedia Deutschland fundraising I tell the story of how we reorganized our codebases along the lines of the DDD strategic pattern Bounded Contexts.

In 2016 the FUN team at Wikimedia Deutschland rewrote the Wikimedia Deutschland fundraising application. This new codebase uses The Clean Architectureand near the end of the rewrite got reorganized partially…

Clean Architecture: UseCase tests

When creating an application that follows The Clean Architecture you end up with a number of UseCases that hold your application logic. In this blog post I outline a testing pattern for effectively testing these UseCases and avoiding common pitfalls.

Testing UseCases

A UseCase contains the application logic for a single “action” that your system supports. For instance “cancel a membership”. This…

Guidelines for New Software Projects

In this blog post I share the Guidelines for New Software Projects that we use at Wikimedia Deutschland.

I wrote down these guidelines recently after a third-party that was contracted by Wikimedia Deutschland delivered software that was problematic in several ways. The department contracting this third-party was not the software development department, as since we did not have written down…

During 2016 and 2017 I worked in a small 3 people dev team at Wikimedia Deutschland, aptly named the FUN team. This is the team that rewrote our fundraising application and implemented the Clean Architecture. Shortly after we started working on new features we noticed room for improvement in many areas of our collaboration. We talked about these and created a Best Practices document, the content…

Want to start a new PHP project? Perhaps yet another library you are creating? Tired of doing the same lame groundwork for the 5th time this month? Want to start a code kata and not lose time on generic setup work? I got just the project for you!

I’ve created a PHP project templatethat you can fork or copy to get started quickly. It contains setup for testing, lining and CI and no actual PHP…

This is a short summary of my 2017 reading experience, following my 2016 Year In Books and my 2015 Year In Books.

Such Stats

I read 27 books , totaling just over 9000 pages. 13 of these where non-fiction, 6 hard science fiction and 8 pleb science fiction.

In 2017 I did an effort to rate books properly using the goodreads scale (Did not like, it was OK, I liked it, I really liked it, it was…

Introduction to Iterators and Generators in PHP

In this post I demonstrate an effective way to create iterators and generators in PHP and provide an example of a scenario in which using them makes sense.

Generators have been around since PHP 5.5, and iteratorshave been around since the Planck epoch. Even so, a lot of PHP developers do not know how to use them well and cannot recognize situations in which they are helpful. In this blog post I…