Stefan Wille

In this article article I explain how to automatically generate the client code for a REST API.

The basic idea is to specify the API in a format called OpenAPI, and then feed that specification into a tool called OpenAPI Generator. The target language in this article is TypeScript.

Why would would somebody generate code for a REST API?

• Writing client side code for a REST API is tedious, repetitive, and error prone. Generating the code automatically solves these issues.
• With TypeScript, it is even more desirable to generate this code, because it means that requests and responses are fully typed, including your deeply structured domain objects. There is no need to tolerate the any type.
• Because the approach is based on a shared API specification, client and server are more likely to stay compatible.

My experience with this approach is in fact very good.

How to customize an Ant Design Theme in react-scripts - easily and without ejecting.

Here I explain how to setup Guard to run 'bundle install' automatically everytime you modify your Gemfile.

Guard watches the files in your project directory, and responds to changes by running a configurable command or plugin. This is very useful functionality. I feel that the Guard website makes it harder than necessary to get started though. Therefore I wrote this tutorial.

Recently, I have published a Redis client library for Crystal called Crystal-Redis.

This week I have published Crystal-Redis, a Redis client for the Crystal programming language. It is open source, full featured, well documented and is very fast.

Nginx 1.4 finally went stable. This new version comes with SPDY integrated. If both web browser and server support it, SPDY improves your site's performance.

I figured out how to get Sphinx / thinking_sphinx to handle searches with german umlauts and treat the umlauts as case insensitive.

I stumbled across a weird issue with bundler on MacOS X:

When you create an image in Rmagick and save it, chances are high that your image will be way too big. The reason is that, by default, Rmagick creates uncompressed images.

Capybara is a great integration testing framework that easily replaces Webrat. Plus, it works with Rails 3, which Webrat seems not to do. If you need to print the current page's content, for example to debug your test, you can do so with:

You probably got this error message in Ruby on Rails: 'invalid multibyte char (US-ASCII)'

Atlassian Crowd offers a simple solution for single sign on. It comes with an authentication server, a web based administration console and Java client libraries. Other Atlassian products such as Jira, Confluence and Bamboo integrate with Crowd. With the crowd_rails plugin, Ruby on Rails can also benefit from single sign on with Atlassian Crowd 2.0.

The new version 0.5.10 of the crowd-stefanwille fixes a bug in handling of validation factors.

I took the Ruby client gem for Atlassian Crowd 1.6 and updated it for Crowd 2.

I use Bundler's command `bundle install` with Capistrano and it used to takes many seconds to complete. The reason was that Bundler fetched all required gems unless they were already installed and then checked for all dependent gems if there is are newer versions available and installed these. It's the last step that took so long.

Probably every agile book recommends to split large user stories (epics) into smaller ones. But why? The reason is usually 'because they are more manageable', but I didn't really understand what that was supposed to mean. Until recently, when we worked on two epics. And I had an insight that I am eager to share.

I found that, once you have software in production, your business people ask for numbers, statistics and reports from your database, on a weekly or monthly basis. And this keeps interrupting your workflow. And it also keeps you from coding. So what to do?

I am searching for a new colleague: A sharp, experienced Ruby on Rails developer for our internet startup Balao in Hamburg.

Google Books has scanned my book Spring & Hibernate:

I found an illegal copy of my book on RapidShare.

SVA BizSphere GmbH has a great page up that describes its product BizSphere, the software that I worked on over the past 2.5 years.

Here is a description of Content Landscape, a project for which I did architecture and specification work during my BizSphere engagement.

Our publisher will start selling the second edition of our book _Spring & Hibernate_ in April, 2008.

On November 23, 2006 I became a Certified Scrum Master (CSM).

On October 26, I spoke about Hibernate at Lehmann's book shop in Hamburg.

A few years ago, I wrote a book called 'Go To JavaServer Pages'. It was published by Addison Wesley in 2001.