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Daniel Bälz Posts

Catching up…

More than a year has passed since the last blog post. The blog was more or less a memory (information) dump for me and sometimes for others. In fact, recently someone asked about slides of a talk and mentioned, that they aren’t on my blog. Based on the activity on the blog you may think, that I did nothing interesting concerning my favorite topics Android and Kotlin? Not even close and so it’s time for a catch up…

To put it in chronological order: I did another talk about Spring Boot 2 and Kotlin in Munich. This time with my dear co-worker Thorsten. The talk was based on the previous one with Hendrik. Thanks again Hendrik for your hard work on the slides and demo project and for letting us use this stuff for our talk. And again, I was just the sidekick responsible for Kotlin knowledge and some lame jokes (“The keyword is f-u-n like function or like fun if you really into Kotlin”). Because it worked out very well, we did the same talk months later in Hamburg.

In March 2019 there was another interesting opportunity to give a talk in English. I spoke at the AndroidHeads Vienna meetup. It was not only my first meetup talk in another country, but also my first about another great Kotlin-related topic: The Gradle Kotlin DSL. It’s a DSL to write Gradle build scripts in Kotlin and get rid of Groovy. An interesting approach, not perfect right now, but with great potential. As part of my talk I did a live demo (again) and uploaded the demo code and the slides on GitHub. Since I was already on it, I also wrote a blog post about the topic on the inovex blog and did (more or less) the same talk on the Mobile Development Karlsruhe meetup.

Obviously, I really like to speak about Kotlin. So, I was very happy (and also very very nervous) when Nico, the host of the German-speaking podcast Techtiefen, asked me if I like to talk about it. At the end we had a good time and talked around 1 1/2 hours. Sometimes with some wild jumps from one topic to another and lots of filler words on my side. But his superb editing skills did just magic word and produced a good podcast.

Beside that I did internal talks, some meetup organization and lots of discussions about Kotlin in other meetups, on the coffee machine and after work. It’s still an interesting topic for me and more stuff related to Kotlin will come in the future.

Kotlin¹, Kotlin² and Kotlin³

Obviously, my current hype topic at conferences, meetups and whenever I meet other developers is Kotlin. Don’t worry, I do something else now and then. 🙂

Let’s start with Kotlin¹. Initiated by GDG Karlsruhe I gave a talk at the Karlsruher Entwicklertag 2018 with the title “Kotlin for Android-Developers”. As the title already says, it was all about Kotlin and how to use it in Android. For this talk I’ve created a new live demo and it was really worth the effort. Thanks to the dedicated audience and their questions, it was a mixture of a few slides, an extensive live demo and a vivid discussion. All in all, a great conference with exciting talks and interesting discussions during the breaks. Thanks to everyone who made this conference possible.

Just a few days later I spoke about Kotlin² again. It was really fun in the square. The topic was Spring Boot 2 and Kotlin, something I’m not that familiar with. Fortunately, I was only the insignificant sidekick for my dear co-worker and backend expert Hendrik. So I contributed some knowledge as Kotlin “expert” (think of even more quotes here) while Hendrik did most of the work at our live demo. The topic was interesting and I took the opportunity to take another look at Spring Boot 2. And above all, we had a lot of fun in the live demo and afterwards.

Last but not least I just couldn’t stop talking about Kotlin³. Therefore, it was really handy that I participated in the current episode of the “What’s happening?” podcast from inovex. In this podcast we talked (in German) about language features, interoperability with Java, some practical advice and how to use Kotlin in your Android app. Thanks to the two hosts Lukas and Christian for their work and this interesting opportunity. Another big thanks to the other guest Chris, who raised many important points in the podcast. It’s always a pleasure to work together or talk about stuff with these guys.

Talks and the future

It’s true, this blog (aka post-conference-slide-dump) needs more care to be useful. One of my personal goals is to write more articles, but I’m not sure if this blog is the right place to post them. Therefore, I’ll disable the comment section and change the theme/design in the future.

However, there are two more talks to mention. I enjoyed both and the discussions afterwards made a lot of fun. The first talk was at the Kotlin User Group Karlsruhe and announced as “A very personal dive into my favorite Kotlin features”. Fortunately, the title and content changed. In the end we had some “Fun with Functions” and the talk consisted mainly of a live demo. This demo covers the topics higher-order functions, extensions functions and function literals with receiver (especially lambda with receiver to create a DSL with Kotlin).

The second talk was a shorter one. I did an introduction into Kotlin at Kotlin Development Karlsruhe meetup. There are no slides or demo code. It was more or less a stripped down and revised version of my talk at GDG DevFest Karlsruhe. (Disclaimer: I’m one of the organizer, so it wasn’t that hard to get a slot in our first meeting)

GDG DevFest Karlsruhe 2017

Although I worked on interesting topics at work and in private, posts on my blog are still rare. However, once a year there’s a good reason to write a post: As in the previous years, I attended at the GDG DevFest Karlsruhe. The conference was great again and I had the opportunity to give a talk. My topic was “Kotlin for Android-Developer”, which is an amazing programming language I’ve use for some time in different projects.

In addition to a few slides in German, my talk consisted mainly of a live demo. I’ve uploaded the demo code on Github. This code is certainly less useful without my explanations, but some participants asked me about it. So, have fun with Kotlin and if you’re interested in a Kotlin Meetup in Karlsruhe: There’s a Kotlin User Group with great talks, discussions and exchange of ideas.

GDG DevFest Karlsruhe 2016

Another amazing GDG DevFest Karlsruhe is over. The DevFest was, as in the previous years, a really great conference. So many interesting talks and curious visitors.

I also contributed to the conference: In my talk I spoke about my experiences in the development of a modern Android app. The talks was held in German and if you’re interested in the slides, I’ve uploaded them here.

Adaptive Code Execution with Dart

Finally, the source code of my master’s thesis is published as open source under the BSD license. In my thesis I developed two libraries to support decision-making at runtime and adaptive code execution with Dart:

Furthermore, a blog post on the blog of my employer inovex GmbH explains the motivation and provides more information about the libraries. I hope the libraries are useful and/or give an interesting glimpse into the topic of adaptive code execution. Feel free to contact me for any questions, fork the project or report issues.


On-Off Tracker app for Android

I’ve just released a new Android application in the PlayStore and the source code on Github. The On-Off Tracker is an application to measure how often the screen has been switched on and off. In addition, it also tracks how often the device is unlocked.

The very small project was initiated by a question of a friend whether such an app is possible. The answer is “yes”. I hope it’s useful for someone and the numbers counted don’t scare. 🙂

Google Play Game Services

I gave a talk on Google Play Game Services at the GDG DevFest Karlsruhe 2014. The talk was in German and I uploaded my presentation:

Google Play Game Services (German)

To show some sample code, I have also written a very simple game for my talk. The source code is on GitHub and you get the game from Google Play. If you’re interested in this subject and you want to discuss with me, then feel free to post a comment or to contact me on Google Plus or GitHub.