Monthly Archives: March 2011

Properties and Probabilities

I just tagged version 0.2 of my tracker browser tool

What’s new?

  • It has a location bar with backward and forward navigation buttons
  • It is also possible to use prefixed names instead of IRIs
  • You can use your keyboard to navigate backward and forward
  • It has a in-page search bar which can be reached by familiar keystrokes like “/” or “Ctrl-f”
  • If you browse a rdf:Property, you will now be shown all resources with the value the property has

Where to get it?

Mandatory screenshots

Tracker and me

While working with tracker I find myself rather often calling “tracker-info” on resources, looking for linked resources, running tracker-info on those, then needing to get back etc. A bit ugly and time-consuming.

Wouldn’t it be cool to just browse through all that info, being able to go back and forth through the links? Yes, it would. That’s why I wrote tracker-zilla:

You can navigate through the resources just like on the interwebs, using the back and forward feature of the context menu. It shows you not only the resources and properties of the object but also resources that link to the one you’re currently browsing:

It’s not that feature-rich and probably never will be. You can either pass a urn to it via command-line or nothing, then it will show you all rdfs:Classes available in the current ontology where you can just click on e.g. nco:PersonContact. What I’m planning to add is a simple in-page search and a breadcrumb navigation.

That said. it’s a pleasure to work with libtracker-sparql (especially from Vala). You need Vala 0.11.6, gtk+-3 and webkitgtk-3.0 to build it. ?The code is available at github.

Update: Due to popular demand, there’s now a –with-gtk=2 option to enable Gtk+-2 UI.

Debunking Rygel myths

Somehow Rygel seems to have gained some interest by users lately, a number of new users show up on mailing list, IRC and Bugzilla. But it seems there are some misinformations flowing around:

Rygel is a UPnP server
Well yes, that’s how it started out. But since then, we’ve evolved to be a UPnP/DLNA framework or even SDK providing easy means of implementing servers and renderer.

Speaking of renderer, we not only have one renderer to offer but actually a multitude. Rygel is a consumer of the MPRIS2 D-Bus specification which means it can turn any player, like Banshee or Rhythmbox, which implements this specification into a UPnP/DLNA media renderer.

Rygel is Gnome-only
While being part of Gnome, using its infrastructure, there’s no reason not to use Rygel as a system service. You might, however, experience some minor drawbacks since some of the plug-ins heavily make use of D-Bus. People already have contributed init scripts to ease this part.

Rygel is badly documented
Hm, yes. That one is actually true. Its documentation is a bit scattered in our wiki at and the man-pages. On the other hand we hope that Rygel working out of the box for most people out there.

Hope that sheds some light.

Ps: Hello Planet Gnome! Great to be here finally.