.NET / C#

Handlebars.Net & JSON templates

I ❤️ Handlebars! So I was very very very happy to see that Handlebars was ported to .NET! It is a mega flexible templating engine as it can easily be extended. I’m currently working on a project where a I need to parse objects via JSON templates to JSON strings. This blog will show how to instruct Handlebars to parse into JSON and add some nice error messages if your template fails.

DateOnly in your .NET 6 API

Let’s face it: sometimes DateTime is just too much: you only want to deal with dates. Since .NET 6, we finally have support for DateOnly. In this blog I’ll look at how to interact with it and how to add it to your Swagger API docs.

The Swiss Army Knife Decorator: exception logging, latency metrics and Jaeger spans combined

At Wehkamp we use decoration a lot. Decoration is a nice way of separating concerns from the actual code. Most of our repositories need the same set of decorators: exception logging, latency metrics and Jaeger spans. In this article I’ll be joining these 3 types of decorator into a single Swiss Army Knife decorator: one decorator to rule them all.

Jaegerize my .NET Core setup!

Adding observability to micro services is vital if you want to discover bottle necks. In this blog, I’ll show how we implemented Jaeger in .NET Core to observe incoming and outgoing requests. We’ll also use a Jaeger decorator to observe spans in classes.

.NET Core & the Google Analytics Real Time Data API

At Wehkamp, we use Google Analytics extensively to measure how many users are active. It is hard to correlate active users with your other statistics that “live” in Prometheus. In this blog I’ll show how you can use the Google Real Time API to produce statistics for active users, page views and screen views.

.NET API: capture original message body

Sometimes you just need to record the original message that was submitted to your API. My colleague Onno Pierik and I encountered such an event. We needed to record the original submitted SOAP message (body) and submit it (under certain conditions) to another service. To be honest: most of the scenarios I’ve seen so far end up with memory problems, so use with caution!

Prometheus Latency Metrics & Exception Logging with Scrutor Decorators

Ever since I stumbled upon the Scrutor project, I wanted to write a blog about building latency and exception logging decorators. At Wehkamp we used StructureMap in the past, but as it became obsolete and swapped out, I missed the decorators. What I love about Scrutor is how it is an extension on the way […]

Dependency Injection based on request headers

Dependency Injection (DI) helps us to change the behavior of parts of our program on the fly. This is especially neat when you want to test your domain services against a mocked data-store. But what if you need to change the behavior of your API based on a request header?

Yesterday I had a discussion with my colleague Robert Kranenburg about this. He showed an example of a console application changing its behavior based on an argument. I took the idea and converted it into .NET Core 3.1 code to change behavior based on a cookie.

“Is One Of” and “Is Not One Of” validation attributes

I love attribute validation! They can be used for a myriad of things. In .NET Core MVC we use them to validate models that come into our controllers. In one of our projects we kept running into the same thing: we need to validate a value against an array of pre-defined values. So we wrote some base validation attributes.

Building a high performing last viewed list using Redis

We live in a day and age in which we can choose a data-store that matches the characteristics of our apps and (micro) services. Lately we’ve been looking into Redis as a high performing store for last viewed items. In this blog I’ll look show how to create a POC with the redis-cli and then implement it using .NET Core. We’ll be using the sorted set structure.