CoffeeScript

Vert.x supports JavaScript through the Rhino JavaScript engine. Although JavaScript is a decent language once you get to know it, I prefer CoffeeScript, a language that compiles to JavaScript. Luckily, vert.x has built-in support for CoffeeScript, so I can use it nearly transparently. You will only notice the JavaScript under the hood when reading stack traces, which will refer to the compiled JavaScript file.

For the examples in this blog post, the only thing you need to know a little CoffeeScript:

foo = (a, b) -> a + b

Translates to the JavaScript code

Event-Driven Concurrency

At synyx, we are looking at vert.x for an upcoming project where we are building a system that will need to scale under load. The tag-line of vert.x is effortless asynchronous application development for the modern web and enterprise, which fits the bill, so I decided to play around with it a little bit.

The advantage of event-driven concurrency compared to traditional technologies is the reduced risk of deadlocks, livelocks and race conditions. Using mutexes and semaphores correctly is extremely difficult and can lead to very subtle bugs that are difficult to reproduce. The downside is that information can only be shared by passing messages.

A few years ago, a good friend of mine installed a small photovoltaic system on his roof. I'm very exited about installing some solar panels on a roof and start producing electricity. It turned out that the installed inverters have massive quality problems. So the idea was born to monitor the whole setup like i know it from computer systems. Each inverter in this system has a serial port interface to transmit data.
But at this time, the market of low cost and low power consuming computers wasn't distinct as it is nowadays. In February 2012, the Raspberry Pi Foundation started to sell Raspberry Pis. I saw this as a chance to get a cheap computer with a minimal power consumption.

Von Montag, den 24.09 und Dienstag, den 25.09, fanden in Köln die OpenCms-Days 2012 statt.

Gemeinsam mit dem ehemaligen synyxer Florian Hopf haben sich Oliver Messner, Fabian Buch und ich schon am Sonntagabend nach Köln begeben.

Am Montagmorgen eröffnete Alexander Kandzior von Alkacon die Veranstaltung mit der Vorstellung der nagelneuen Version 8.5 und demonstrierte hierbei direkt den neuen Editor, der das Arbeiten vereinfachen und beschleunigen wird. In diesem Zusammenhang wurde auch eine Solr-Integration für mehr Suchmöglichkeiten und eine CMIS-Anbindung zum Zugriff auf Content durch diesen Standard vorgestellt.

Es folgten Vorträge zum Thema OpenCms und zur Entwicklung mit OpenCms bis hin zur High Availability und zum Continouos Integration.

Die 7. "Free an Opensource Software Conference" fand zwar schon letztes Wochenende in St. Augustin (nahe Bonn) statt, aber darüber zu bloggen lohnt sich dennoch. Denn die FrOSCon ist mit 5€ Eintritt (bzw. 100€ Business-Support) nicht nur eine der günstigsten Konferenzen, sondern wie ich finde auch eine der lohnenswertesten.

Die Gründe hierfür sind zahlreich, es wird sehr sparsam mit den Worten "business", "cloud", "oracle" und insbesondere "enterprise" umgegangen. Letzteres eigentlich nur im Bezug auf den Internet Explorer 6 gehört . Es gab jede Menge themenbezogene Räume und die Tracks "Administration" "Entwicklung" und allgemeine Nerd-Technik waren recht ausgeglichen und allesamt interessant.  Ein weiteres Alleinstellungsmerkmal der Konferenz ist die Hüpfburg, im Hof der Fachhochschule, die unter Berücksichtigung der Regel "kleine Nerds vor großen" nicht nur für Kinder ein Spass ist.

While working on one of my projects we were faced with the problem of creating a report with a big amount of data to show on multiple Excel tabs (about 50000 entries grouped by different criteria's). We had a couple of requirements that lead us to choose Jasper Reports as our report generation engine. Other requirements lead us to use XML as data source - e.g. to generate the report on the fly without wasting hard disk space for different languages.

It is hard to imagine a web project without JavaScript code today. JavaScript is an easy to learn and very performant script language. In the past we have used JavaScript mostly for eye-candy and form validation. Recently we have been asked more often to implement complex user interfaces with trees, sortable tables and things like that. So we decided to rely more on JavaScript to improve the feedback of the website to user actions.

The first question that came up was: How to develop test driven with JavaScript?
We decided to use Jasmine, a behaviour driven development framework which tests can be run headless in a Maven build for example.

Wie versprochen ist das Ressourcenplanungs-Tool unter dem Namen synRP jetzt auf github erhältlich:

github.com/Synyx/synRP

More and more Projects at our company are taking advantage of distributed and local revision control by using git. So to make a complete software-project fit for git, by not only using git-svn with subversion and git on top, some more steps are required than just handling files with git, learning its syntax and understanding the way it works…

Matching the time of my talk at this years OpenCms Days we released our module for integrating Solr with OpenCms. A few days have passed now and we had the time to polish the documentation and some aspects of the module.

Solr is a search server that is based on the de facto standard for indexing in Java, Apache Lucene. It provides an abstraction layer above the low level details of indexing and adds some useful features like facetting and synonyms.

Solr is integrated transparently as an OpenCms index and can be used and mixed with common Lucene indexes. Communication is done via HTTP, Solr is accessed using a REST based interface.