Extensions in Action

Because extensions seem to be experimental and volatile at this stage (0.41+CVS), I would like to see some extensions working in Inkscape before I get started. Inkscape extensions are well camoflaged and tightly integrated. Extensions hide in the File -> Open and File -> Save As dialogs. Input and output of various file types are enabled via extensions. I am mostly interested in the filter type of extensions that allow modification of the current document. Filter extensions or effects are more difficult to find in 0.41 because the Effects menu is disabled by default. To enable the Effects menu add a 'show-effects-menu="1"' attribute to the group labeled 'id="extensions"' in your preferences.xml file. You may have to add the group if it does not exist. It should look similar to this:

  <group
     show-effects-menu="1"
     id="extensions">	</group>

Inside the Effects menu I find Blur Edge, Grid and a few other extensions that ship with Inkscape. Most of these effects are Plugins, extensions written in a compiled language like C or C++ that are loaded from library files. The Dropshadow effect is different. It is a perl script. Since I want to build extensions in Python, Dropshadow should be a good test of the extension mechanism using scripts.

I'd first like to take a look at the Dropshadow script. My Inkscape installation prefix was /usr/local. To find the files related to extensions I look in /usr/local/lib/inkscape/plugins/ and /usr/local/share/inkscape/extensions/. Running the /usr/local/share/inkscape/extensions/svg_dropshadow from the prompt reveals that I am missing a required perl package. I fixed that with the following command.

apt-get install libxml-xql-perl

Now back in Inkscape and clicking Effects -> Dropshadow adds an svg dropshadow to the selected objects. It works!