D-Bus service for Apertium
D-Bus is a simple inter-process communication system. We are in the process of developing D-Bus services for Apertium which will make programmatic access to the Apertium tools easier. We have started developing simple D-Bus bindings for Apertium which allow for:
- discovery of details of the current Apertium installation and,
- translations via a programmatic interface.
The D-Bus bindings are needed for some of the tools, such as Apertium-view and Apertium-tolk.
Prerequisites
- apertium (>= 3.0.0)
- python
- dbus
- python-dbus
Installing
The package is available from SVN in the apertium-dbus module. The process for installation is the standard:
$ svn co http://apertium.svn.sourceforge.net/svnroot/apertium/trunk/apertium-dbus
$ ./autogen.sh $ make $ make install
Note: The current svn tip is ported to Python3, but doesn't seem to work:
$ /usr/local/share/apertium/dbus-1/info.py -p /usr/local
Traceback (most recent call last):
File "/usr/local/share/apertium/dbus-1/info.py", line 78, in <module>
service.run_as("org.apertium.info")
File "/usr/local/share/apertium/dbus-1/service.py", line 37, in run_as
mainloop = gi._gobject.MainLoop()
AttributeError: 'module' object has no attribute 'MainLoop'
Do "svn up -r25849" to get the working Python2 version.
Check that it works
You can check that the bindings work by issuing the command:
dbus-send --print-reply --dest=org.apertium.info / org.apertium.Info.modes
This should return an array of strings of all the Apertium modes installed on your system. It should look something like
$ dbus-send --print-reply --dest=org.apertium.info / org.apertium.Info.modes
method return sender=:1.567 -> dest=:1.599 reply_serial=2
array [
string "en-ca"
string "ca-en"
string "en-af"
string "af-en"
]
To translate from the command line (assuming apertium-en-ca is installed), try e.g.
$ dbus-send --print-reply --dest=org.apertium.mode / org.apertium.Translate.translate string:en-ca dict:string:string:"mark_unknown","true" string:'My hoovercraft is full of eels'
If the above two commannds don't work, then it's quite possible that a Python error from our side snuck in. Try running info.py directly; that is
python info.py -p /usr/local
where the prefix for Apertium in the above example is /usr/local. If you get a Python error, please post the error on this page or post a bug report in our bug tracker. If the service starts up without errors, try executing
dbus-send --print-reply --dest=org.apertium.info / org.apertium.Info.modes
again. If there is no output, then open a new terminal and run
dbus-monitor.
This neat utility shows you the activity on the D-Bus. Now try executing dbus-send --print-reply --dest=org.apertium.info / org.apertium.Info.modes again.
If you have no luck, come and talk to us in #apertium at irc.freenode.net
Installing into a prefix
- This is unfinished
- Do: mkdir -p <prefix>/share/dbus-1/services/
- Make a session-local.conf file like it says here under "" Configuration Information"".
- Change the <servicedir> element value to <prefix>/share/dbus-1/services/
- Restart dbus. /etc/init.d/dbus restart
- Log out and log back in again
Interfaces
Currently, Apertium offers two D-Bus services:
org.apertium.infohas a single object/, which offers rudimentary information about the Apertium installation.org.apertium.translatecontains an object for each Apertium mode installed in the system.
Issues
If you make a change to any of the D-Bus configuration files, you will need to restart both the system-wide and session D-Bus daemons. The system-wide daemon can be restarted on a Debian/Ubuntu system with:
/etc/init.d/dbus restart
The only real way to restart your session deamon is to logout and log back in again. You will likely run into strange problems if you attempt to kill the session D-Bus daemon.
Filesystem layout
/usr/share/dbus-1/services/— DBUS.servicefiles./usr/share/apertium/dbus-1/— Python code that actually does the service (info.pyandmode.py)
Examples
There are some simple examples in various languages on the page D-Bus examples.
