
How to use pywws in another language
************************************

1. Introduction.

   Some parts of pywws can be configured to use your local language
   instead of British English. This requires an appropriate language
   file which contains translations of the various strings used in
   pywws. The pywws project relies on users to provide these
   translations. This document describes how to create a language
   file.

   The pywws documentation can also be translated into other
   languages. This is a lot more work, but could be very useful to
   potential users who do not read English very well.

2. Dependencies.

   As well as the pywws software you need to install the 'gettext' GNU
   internationalisation utilities package. This is available from the
   standard repositories for most Linux distributions, or you can
   download it from http://www.gnu.org/software/gettext/ if you need
   to compile it yourself.

3. Choose your language code.

   Computers use IETF language tags (see
   http://en.wikipedia.org/wiki/IETF_language_tag). For example, in
   the UK we use 'en_GB'. This has two parts: 'en' for English, and
   'GB' for the British version of it. To find the correct code for
   your language, consult the list at
   http://www.gnu.org/software/gettext/manual/gettext.html#Language-
   Codes.

4. Getting started.

   Your pywws directory should already have a subdirectory called
   translations. This contains the existing set of language files, for
   example 'translations/sv/pywws.po' contains the Swedish
   translations. If one of these languages is what you need, then edit
   your weather.ini file and add a 'language' entry to the '[config]'
   section, for example:

      [config]
      day end hour = 21
      gnuplot encoding = iso_8859_1
      language = sv

   You may still need to compile and install your chosen language
   file. This is done by the 'makefile' included with pywws:

      make lang LANG=sv

   If there isn't already a file for your language, the rest of this
   document tells you how to create one.

5. Create a language file.

   The 'makefile' included with pywws can create a file for you to
   fill in. For example, to create a source file for the French
   language (code 'fr'):

      make lang_src LANG=fr

   This will ask you to confirm your email address (several times,
   annoyingly), then create several '.po' files in the directory
   'translations/fr'. You should now edit 'pywws.po', filling in every
   'msgstr' line with a translation of the 'msgid' line immediately
   above it. The reason for including your email address is to allow
   anyone who has questions about your translation to get in touch
   with you. Feel free to put in an invalid address if you are
   concerned about privacy.

   After you've edited your new language file it needs to be compiled
   so that pywws can use it. This is also done by the makefile:

      make lang LANG=fr

   Don't forget to do this every time you edit a language file.

6. Test the pywws translation.

   The Localisation.py module can be used to do a quick test of your
   language file installation:

      python code/RunModule.py Localisation -t fr

   This should produce output something like this:

      Locale changed from (None, None) to ('fr_FR', 'UTF-8')
      Translation set OK
      Locale
        decimal point: 23,2
        date & time: lundi, 17 décembre (17/12/2012 16:00:48)
      Translations
        'NNW' => 'NNO'
        'rising very rapidly' => 'en hausse très rapide'
        'Rain at times, very unsettled' => 'Quelques précipitations, très perturbé'

   Edit the language entry in your weather.ini file to use your
   language code (e.g. 'fr'), then try using Plot.py to plot a graph.
   The X-axis of the graph should now be labeled in your language,
   using the translation you provided for 'Time', 'Day' or 'Date'.

7. Send Jim the language file.

   I'm sure you would like others to benefit from the work you've done
   in making a new language file for pywws. Please, please, please
   send a copy of your language file (for example pywws.po) to jim
   @jim-easterbrook.me.uk.

8. Update the language file.

   As pywws is extended, new strings may be added which will require
   your translation file to be extended as well. This is fairly easy
   to do. First you need to remove the language master template file,
   then run the 'make lang_src' command again:

      rm translations/pywws.pot
      make lang_src LANG=fr

   This should add the new strings to your language file, without
   changing the strings you've already translated.

9. Translating the documentation.

   The system used to translate the strings used in pywws can also be
   used to translate the documentation. The files 'index.po',
   'essential.po', 'guides.po' and 'api.po' contain text strings
   (often whole paragraphs) extracted from the different parts of the
   documentation.

   These files can be edited in a similar way to 'pywws.po'. Fill in
   each 'msgstr' with a translation of the 'msgid' above it. Note that
   some strings (such as URLs) need not be translated. In these cases,
   leave the 'msgstr' blank.

   Translating all of the pywws documentation is a lot of work.
   However, when the documentation is 'compiled' any untranslated
   strings revert to their English original. This means that a partial
   translation could still be useful - I suggest starting with the
   documentation front page, 'index.po'.

   Comments or questions? Please subscribe to the pywws mailing list
   http://groups.google.com/group/pywws and let us know.
