[JimmXinu]

I have a first stab at an i18n/l10n version of a plugin using my smallest plugin, SmartEject.

First, I went through and wrapped all the UI strings in _(). Then, taking what I found in calibre/utils/localization.py as inspiration, I added a l10n.py file containing:

try:
    from calibre.utils.localization import get_lang

    mofile = get_resources("l10n/messages_%s.mo"%get_lang())

    import cStringIO
    from gettext import GNUTranslations
    trans = GNUTranslations(cStringIO.StringIO(mofile))
    
    def gettext(x):
        return trans.gettext(x)

except Exception, e:
    def gettext(x):
        return x

Then in my plugin code files I added:

from calibre_plugins.smarteject.l10n import gettext as _

First, I:

1. used pygettext.py to generate a messages.pot file from my source .py files,
2. copied that to l10n/messages_en.po,
3. edited that with Poedit to add "(en)" a few places for proof it worked,
4. created .mo file and
5. included l10n/messages_en.mo in the plugin zip file.

That version of SmartEject is posted here.

I will not be in the least surprised if I've over looked any number of additional details, but it's starting point.

Issues I've identified with this process so far:

1. In an ideal world (for plugin in writers anyway), the functionality in l10n.py would be part of the plugin base classes and plugins would just use _() and provide .mo files in a standard directory in the plugin zip.
2. Should the plugin name itself in the InterfaceAction and InterfaceActionBase child classes be localized? What happens to users with the plugin already installed if it changes?
3. What's the best practice for maintaining the .po files? How do you update existing .po translations to add new UI strings?
4. Are/Should translated versions of the plugin forums exist somewhere? Like the plugin index page?