In order to give students and other interested people some more insight at what might be the next big thing according to our optimistic opinion, this blog now features a research category.

The first entry shall be about my pet project Dynvoker. While I'm currently not able to work on it much during my work time, there are still some changes now and then. One of the most recent additions is a WADL parser contributed by Christian Liebing. Along with other modifications, the dynvoker-generic-branch transforms the application into a multilaterally generic framework. The generic dimensions encompass the service description formats, the output formats, the protocol for communication with the web service and the choice of runtime environment. A fifth, rather imaginary dimension would be the integration into complex processes.

Going generic is essential in service-oriented environments, given that on the one hand the promise of SOA is the flexible wiring and re-wiring of services, and on the other hand there is as always a plethora of protocol options available in real-world applications.

The following picture illustrates the options between output formats and submission formats alone:

Add to this that various service description formats support several submission formats, and the confusion arrives at the highest level. But do ordinary users care? No, they certainly don't, and that's why user interfaces for services need to hide this complexity. The generic approach of Dynvoker is an important step into this direction. Details will be presented at the ServiceWave 2008 conference in Madrid which also has a workshop on common goals towards UIs for services. Let's see if I will be able to attend since at the same time there's another workshop on monitoring and adaptation, my current dia em dia topic which will soon lead to another blog post.

The GGZ Gaming Zone server ggzd is able to reject weak passwords using the cracklib or omnicracklib libraries. Omnicracklib has been written from scratch and has been designed to not repeat the functionality and API restrictions that cracklib has. Up until now, this small library has just been sitting in GGZ SVN without any chance to let people pick it up and suggest improvements. Now, more information and the download is easily possible on the omnicracklib website.

East Saxony's largest geek gathering and bringing-free-software-to-the-people initiative Linux-Info-Tag will be hosted once again at Technische Universität Dresden on November 8, a Saturday. We expect a couple hundred people to join us on that day.

This year's highlights include an OpenStreetMap mapping tour through our zoo, and the distribution of free CDs with free-as-in-speech music. I've already ordered a replacement adapter for my N810 since the original one broke.

We also offer many talks, workshops, project and information booths, a key signing party, an install party and several additional goodies. Among the projects, Kubuntu, OpenOffice.org, Wikipedia, KDE and Debian are probably the most well-known ones. Python is the project with the strongest presence this year, however.

The calendar(1) command does not contain a lot of information about events which happened on an eighth of November. It does, however, include the following gem: En novembre, s'il tonne, l'année sera bonne. Truth has been spoken, for our event will rumble for sure!

The KIO framework has been with KDE since eternity, in some parts long before KDE 2 came out if I'm reading the meta information correctly. It provides us with many useful slaves, including one for HTTP and WebDAV. However, despite the hours of work which went into it, and despite the fact that it works very well for most of the time, we can do better. The software world beyond the desktop is making its functionality increasingly available through well-defined interfaces. We, on the other hand, need a good API to make the ubiquity of services a reality. If we provide one, more developers will consider our libraries as a good choice for their applications.

As one of these developers, the difficulty to access services with a REST interface has annoyed me for quite some time. At first I've thought that the mistake must be with me or my source code, but now that patches to KIO are available I know that it was simply impossible before. Now it is finally possible.

(To be fair, SOAP users had a similar issue in early KDE 4 times. And with the new KXMLRPC library, operation-centric web services seem to have a good standing with KDE, too.)

Back to the topic. How much functionality should such a framework contain? Everybody wants it to be as light-weight as possible, and I agree. Still I'd like to see some additional functionality over the state transfer handling it does right now. Its techbase page already mentions a resource cache and a transfer cache. The transfer cache will avoid forcing the application developer to handle network connection trouble. If a transfer fails due to a server being down or the laptop's ethernet cable being loose, why should the developer have to care? Robustness by automatic failure handling is therefore worth the additional couple hundreds lines of code in any case. The resource cache, on the other hand, will be more or less duplicating the kio_http cache, but on the other hand might give the developer more control about the amount and strategy of caching. Unfortunately there's no generic caching layer in KDE yet which we could simply use at this point even though many other libraries like KNewStuff or KGGZ could profit from such a layer. If access to services becomes ubiquitous, then caching will as well.

Other than these two extensions to Lokarest, I can't think of any which I'd need in any or at least most applications using this framework. But there might be others hidden more deeply. Interestingly, Sun recently released a reference API for accessing REST services through their JCP, but beware that its licence is inherently non-free and tried to prevent alternative implementations. If that's not the intention and just the wording, the company should get better lawyers who can bring their point across more clearly. If it is indeed the intention, then good riddance JCP and welcome free, unencumbered alternatives from KDE's playground area.

fup2 kde-services-devel

For some days I've been to Ukraine with the purpose of attending two conferences and giving talks at both of them. Visited sites on the Crimean peninsula include Sim City, Balaklava, Sevastopol and Yalta.

My plan was to give the mapping capabilities of Maemo a try. However, this only worked for one battery cycle, since then the N810 refuses to recharge. The routes have been uploaded to OSM already, which caused some trouble at first since I forgot to reset the track after having left Germany:

A sea route along the coast, some inner-city stairs with a statue of Lenin and a hiking route to the highest mountain on the coast of Balaklava have been added now, though, and are visible at least in the Osmarender map.

Beside the charger problem, my digital camera passed away after nearly 5,800 photos. I've already bought a new one, but still I missed out pictures from the otherwise fantastic landscape.