Matthias Nehlsen

Software, Data and Stuff

Weekly Update: git vs brain fart, Octopress, Sony A7, my audio setup

In this weekly update, I will show you how git helped me alleviate the disastrous consequences of a brain fart. I’ll also share my experiences with Octopress. You will learn what helps me feel better, day in and day out. Then, there are some changes regarding the mailing list for this blog. Also there are reviews on my audio setup for a combined work / chill area and on the Sony A7 full frame camera.

Building a geo-aware link shortener with Play Framework

Last week I wrote about blog monetization through the Amazon Affiliate Program. I needed a way to serve country specific URLs depending on the location of the page visitor, so I wrote a geo-aware link shortener using Play Framework. This week I would like to introduce that application. The source code is available on GitHub. You may find that tool useful for your own purposes, or you might just want to read this as a tutorial on how to call backend services with Play Framework and the asynchrous WS client.

Weekly Update: Buying time, AngularJS Meetup, Mountains

Here’s something new to try, a weekly update, covering pretty much what I keep myself busy with. That can be what I am reading, what I am learning and what I am currently working on, mostly software-related. In this installment I discuss monetization, the Hamburg AngularJS meetup and photography in the mountains while hiking.

BirdWatch with ClojureScript and Om explained

WORK IN PROGRESS, last update on August 18th, 2014

I wrote about having written my first actual application using ClojureScript and Om, a web client for my BirdWatch application. You may want to start with that article to understand the background better. This week I first want to talk about my experience with ClojureScript and Om thus far. Then I want to start describing the implementation details. I am fully aware that what has come out of it thus far is far from elegant in terms of pretty much everything. But in my defense, it does appear to work :)

Distributed Atmospheric Pressure Measurement

Later this month I will be doing a hiking tour in the Alps around the Matterhorn. I do not recall exactly why I said yes to this tour; maybe because I did not know at that point that in ten days the total ascent would be 10,500 meters (roughly 34,500 feet). But on the other hand, that’s an interesting challenge for a person with a sedentary job. Now being me, I would love to have a way to track the current altitude plus the combined ascent. GPS can help here, but the best sensor to have for this task appears to be a barometer.

Updated Approach

So I have been suffering a little from writer’s block recently. Well, no, that is not exactly true. The problem was not getting started with a topic but rather sticking with it and continuing to work on it. But there might be a way to get back into the rhythm and that is by finishing something smaller.

Play Framework, Server Sent Events and Internet Explorer

Next week I will be presenting at Scala Days. In my talk I will discuss how to build reactive applications with two-way (near) real-time communication, using the combination of Server Sent Events for providing clients with updates and REST calls for the backchannel. You may already be familiar with two examples of this architecture: BirdWatch and sse-chat. Now I was thinking about potential questions in the Q&A session after the talk. One potential issue that came to mind almost immediately was the support for Internet Explorer. Out of the box, IE does not support Server Sent Events. Personally, I do not care very much about IE support. I have not used it in years before I started researching for this article, and only a low single digit percentage of visitors on my blog use IE. But I understand this can be a showstopper. So if you don’t care about IE support at all, you really don’t need to read any further. Otherwise, bear with me.