Roy van Kaathoven
Full Stack Developer

Apr 26New Blog Post

Opening gates with Slack and Twilio

At one of my clients there is an automated barrier blocking the private parking space. The first day i arrived i had to call their office which they in turn would call a number which controlled the barrier. When the number is called it would sound a busy tone, hang up, and open the barrier. When i wanted to head home i had to drive to the barrier, call the office number and they would call the gate number which would open the barrier. Since opening the gate is triggered by calling a …

Oct 22New Blog Post

Isolating memory leaks in a concurrent system

While working on Advanced-Forms i have to deal with various memory issues which arise when running the server application. The server component of Advanced-Forms is a continuously running background service which can run many different components in parallel at any given moment. Some of these components are third party maintained by other companies or open sources projects like FTP, Mail, Data Conversions, etc.. Sometimes a component will leak memory and it has to be traced down. When i …

Oct 01New Project
May 05New Blog Post

Implementing GCM server with Scala and Akka

I started working on an Android app for the Roboflow project. I have a LG Watch R and i thought it would be handy to be able to send notifications from a flow within Roboflow. So users can easily configure notifications for themselves for the things that matter. To get started i had to implement a client. Following the GCM Client Documentation was pretty straightforward and after some reading and by following the examples i quickly had a working client. Maybe i will talk more about this …

Dec 30New Blog Post

Solving Paper Mazes with Python

Every year just after Christmas there is a quiz game called "De Rooise Kwis" in which a lot of people in Sint Oedenrode participate. This year there were 151 teams. The quiz consists of questions in a wide range of categories, which can be found here As soon as we got the questions we formed pairs to solve a different category, i was assigned to the puzzles. While scanning through the questions i quickly saw the large maze which had to be solved. There are letters in the maze …

Nov 06New Project
Nov 06New Blog Post

Translating urls in Zend Framework 2

Recently i needed to build a multi language website using Zend Framework 2. The framework has a lot options to translate the website, but one thing that was lacking in the documentation was a method to translate URL's. After some research i found a Pull Request which adds the ability to translate routes. The current version only supports the Segment route for now, which is fine for basic routing. In order to start translating routes the router needs to be aware of the translator, do this …

Oct 10New Blog Post

Akka Event Bus

I've been working on a new project for a while which is based on Scala , Play Framework and Akka . The goal of the project is to create a library which can communicate with the Steam Servers, and using the library write multiple bots which perform various actions, like starting trades with other Steam users and exchange items. There can be any number of bots online and their events can be handled by a varying number of services. The services should not have a hard dependency on eachother …

Sep 24New Blog Post

Scraping with Scala

A few months ago i got asked if i could scrape data from various websites, store it in a database and output some nice reports. Back then i've written a simple scraper with Ruby and Nokogiri , saved everything to a Microsoft SQL database and created reports using Excel. Because of the tight budget the script became a quick and dirty solution, but it did the job and the client was happy. Now that the scrape requests are becoming more common i wanted to design a framework in Scala which should …

Aug 19New Blog Post

Scalext: Ext JS module for Play Framework

I've been working on a project called Scalext for a while and want to share the current version and upcoming ideas. Scalext is a module for Play Framework 2.1 which makes working with Ext JS a lot easier. I've already implemented a Ext JS Module for Zend Framework 2 in the past which made writing a similair module in Scala a way to compare the language with PHP. The current version of the module has most features from KJSencha implemented and took a lot less code than the PHP version. The …