WorldclockScreenlet uses python-dateutil

[Ketil Wendelbo Aanensen]

WorldclockScreenlet was uploaded to -extras today. First hitch is that is needs python-dateutil on Ubuntu Intrepid. Possibly called the same thing in other distros?
So,
1: python-dateutil needs to be made a dependency, or
2: WorldclockScreenlet needs to let the user know that the package is needed (+ the package is set as a suggestion)

I think we should go with #2 in these cases, and I think there is at least one screenlet that already does this (something web related, I think).

Rationale:
If we use #2 we can avoid bringing all the dependenciues and their grandma, keeping the necessary stuff to a minimum, and let users that actually use the specific screenlets install the necessary packages.
-extras will likely be a bigger and bigger package, and we need to avoid that it also brings in a thousand deps.

It is probably a good idea to make a packagekit stack in U-A that deals with this stuff, letting developers put in a line or two of code to get what they need.

[Ketil Wendelbo Aanensen (ketilwaa-deactivatedaccount)]

Forgot the output:

$ python /usr/share/screenlets/WorldClock/WorldClockScreenlet.py
Traceback (most recent call last):
  File "/usr/share/screenlets/WorldClock/WorldClockScreenlet.py", line 68, in <module>
    from dateutil.tz import *
ImportError: No module named dateutil.tz

[Natan Yellin (aantny)]

The second option sounds good. I'll write up a blueprint for adding an API to specify package requirements.

[Natan Yellin (aantny)]

This bug should be fixed independently, but please see https://blueprints.launchpad.net/universal-applets/+spec/track-package-requirements-api regarding the package API.

[Julien Lavergne (gilir)]

For this case, python-dateutil only depends on python. No need to make super huge stuff just for some Ko.

For general purpose, option #2 make sense for dealing with all depends for all distro. It seems also that a rss ua have a hack to deal with python-feedparser depends (pop up saying it need python-feedparser).

FYI, for debian/ubuntu, all depends of python modules are set to Recommends. It means that there are installed automaticly when you install u-a-extras, but you can after remove them without removing ua-extras package.

[Natan Yellin (aantny)]

Thanks Julien.

(Julien committed a fix in revision 167.)