Programming

Jump-starting Slack bot projects: bot-zero

To give teams a jump start we’ve created the bot-zero open source project. It solves some setup and development problems. In this blog I’ll show how to get up and running in minutes and I’ll explain some of the choices we’ve made.

Dependency injection (with IOptions) in Console Apps in .NET

When you are used to building web applications, you kind of get hooked to the ease of Dependency Injection (DI) and the way settings can be specified in a JSON file and accessed through DI (IOptions). It’s only logical to want the same feature is your Console app.

.NET Core MVC: regex routing with named groups

One of the big advantages of the .Net regular expression implementation is named groups.  Today I want to show how to leverage named regular expression groups to build a routing constraint that will map each group value to a named route value.

Hubot + ES6 + Promises

Lately we’ve been playing around with ChatOps at Wehkamp. We added a Hubot to our Slack channels to automate some operational jobs. It makes work more fun and way easier. As it is hosted in our own infrastructure, it can interact with our micro-services. In this article I explore how to use ES6 and a Promise to implement a call to a simple web-service.

Linq: round-robin ordering based on segments

Linq is a wonderful way to work with lists in C#. This article focuses on how you can create a round robin ordering for segments of your list. It will distribute items of each segment evenly over the list.

Draw .Net Core project relations with PowerShell and yUML

Having a diagram of how your C# projects interlink, can be a big help. I’ve created a small PowerShell script that will produce the diagram based on the .csproj files in a directory. It will generate Yuml.me diagrams based on the dependencies!

Conditioning Knockout Observables: reject values

Wouldn’t it be nice if we could restrict the value written to a Knockout observable? Some values might mess up your model completely while others just don’t make sense. How would one create a conditioned observable that rejects invalid values? It turns out that conditioning an observable is not so hard.

Calculations with Roman Numerals using C#

In a previous article I wrote how to parse Roman Numerals in C#. This article will focus on how to calculate with the class in an intuitive way. It will show how to implement implicit casting and the add and subtraction operator overloads. Fun stuff that’s probably useful in other projects.

Parsing Roman Numerals using C#

Lately I’ve become fascinated with the Latin language. I’m working on a project that converts photographs of Latin inscriptions on medieval statues into translated text. One of the challenges is parsing years, usually expressed in the form of Roman Numerals.

After building a parser class I noticed that it had a lot of nice characteristics: parsing, operator overloading, implicit conversions. A nice way to play around with C#.

Dynamically map JSON commands to object methods in .Net

Lately I’ve been playing around with USB led lights in .Net. I wanted the animations to be separated from my code. Wouldn’t it be great if you could define what animations are executed in a JSON file? And map it to code?

Normally one would build a mapper that does the conversion of the JSON commands to the methods. I like to use a more generic approach. I’ve created a small utility class that executes commands by mapping and executing them as a method of the object.