A. Rothuis

In lectures regarding object-oriented programming, I sometimes encounter students questioning the use of Java's interfaces. Why do we need to go through the hassle of defining a class as well as an interface? Once they are convinced (or conditioned) to use them, the questions do not end: students often wonder when interfaces are and are not necessary and how they can contribute to well-designed software.

In this post, we will uncover the power of protocols, a more general term for interfaces, and dive into some common implementations. Along the way, we will discuss why interfaces are useful and how they are commonly used to shape the design and architecture of (object-oriented) software.

One of the primary objectives when designing software is to strive for simplicity. We are reminded of this through acronyms, adagia and our failure to easily comprehend our colleagues’ — or, perhaps more often, our own — code. But what does it mean to “Keep It Simple, Stupid”? And when is software too complex?

In this post, we will explore complexity from the perspective of execution flow in our code. We will have a look at a formal, rigorous method of assessing this complexity and, even though these measures are not novel, they are still worth knowing (and trying out) when striving for quality software.

At the time of writing, there is an ongoing discussion in ECMAScript Technical Committee 39 (TC39) regarding the implementation of a pipeline operator. At the same time, there has been an open RFC in the PHP community regarding a pipe operator since 2016. It seems that multiple communities would like a pipeline operator. But why?

In this post, we will explore which problems a pipeline operator would solve and how other languages deal with these problems.

I have been using Docker for a lot of things. For example, docker-compose is extremely useful for quickly setting up a service-based development environment.

Recently, I had the need to run a command once in a Docker image and do something with the file output. For instance, this is quite useful when encapsulating a compilation step or when processing data from one file to another using a docker image, so a user only needs docker as a dependency and the image does the rest.

In this short post, we will explore using files in one-off docker commands with and without defining a custom Dockerfile.

Nowadays, it is important to offer a secure connection through your website via HTTPS and TLS/SSL. Getting a certificate used to be costly and difficult. Luckily, Let's Encrypt offers a free and relatively simple way of setting up HTTPS for a certain domain.

Certificates from Let's Encrypt are valid for 90 days. This means that we have to manually renew our certificate and update our site. At the time of writing, GitLab.com does not have a way of automatically renewing certificates for GitLab pages that use their own domain name.

In this post, we will configure Let's Encrypt for our GitLab pages site, under a custom domain, but hosted on GitLab.com. We will automate the process using GitLab CI, Personal Access Tokens and gitlab-le.