blog/data/2017-01-04-icalendar-archiver.txt

   1 Title: Introducing ical-archiver to split out old iCalendar entries
   2 Tags: english, standard
   3 Date: 2017-01-04 12:20
   4
   5 <p>Do you have a large <a href="https://icalendar.org/">iCalendar</a>
   6 file with lots of old entries, and would like to archive them to save
   7 space and resources?  At least those of us using KOrganizer know that
   8 turning on and off an event set become slower and slower the more
   9 entries are in the set.  While working on migrating our calendars to a
  10 <a href="http://radicale.org/">Radicale CalDAV server</a> on our
  11 <a href="https://freedomboxfoundation.org/">Freedombox server</a/>, my
  12 loved one wondered if I could find a way to split up the calendar file
  13 she had in KOrganizer, and I set out to write a tool.  I spent a few
  14 days writing and polishing the system, and it is now ready for general
  15 consumption.  The
  16 <a href="https://github.com/petterreinholdtsen/ical-archiver">code for
  17 ical-archiver</a> is publicly available from a git repository on
  18 github.  The system is written in Python and depend on
  19 <a href="http://eventable.github.io/vobject/">the vobject Python
  20 module</a>.</p>
  21
  22 <p>To use it, locate the iCalendar file you want to operate on and
  23 give it as an argument to the ical-archiver script.  This will
  24 generate a set of new files, one file per component type per year for
  25 all components expiring more than two years in the past.  The vevent,
  26 vtodo and vjournal entries are handled by the script.  The remaining
  27 entries are stored in a 'remaining' file.</p>
  28
  29 <p>This is what a test run can look like:
  30
  31 <p><pre>
  32 % ical-archiver t/2004-2016.ics
  33 Found 3612 vevents
  34 Found 6 vtodos
  35 Found 2 vjournals
  36 Writing t/2004-2016.ics-subset-vevent-2004.ics
  37 Writing t/2004-2016.ics-subset-vevent-2005.ics
  38 Writing t/2004-2016.ics-subset-vevent-2006.ics
  39 Writing t/2004-2016.ics-subset-vevent-2007.ics
  40 Writing t/2004-2016.ics-subset-vevent-2008.ics
  41 Writing t/2004-2016.ics-subset-vevent-2009.ics
  42 Writing t/2004-2016.ics-subset-vevent-2010.ics
  43 Writing t/2004-2016.ics-subset-vevent-2011.ics
  44 Writing t/2004-2016.ics-subset-vevent-2012.ics
  45 Writing t/2004-2016.ics-subset-vevent-2013.ics
  46 Writing t/2004-2016.ics-subset-vevent-2014.ics
  47 Writing t/2004-2016.ics-subset-vjournal-2007.ics
  48 Writing t/2004-2016.ics-subset-vjournal-2011.ics
  49 Writing t/2004-2016.ics-subset-vtodo-2012.ics
  50 Writing t/2004-2016.ics-remaining.ics
  51 %
  52 </pre></p>
  53
  54 <p>As you can see, the original file is untouched and new files are
  55 written with names derived from the original file.  If you are happy
  56 with their content, the *-remaining.ics file can replace the original
  57 the the others can be archived or imported as historical calendar
  58 collections.</p>
  59
  60 <p>The script should probably be improved a bit.  The error handling
  61 when discovering broken entries is not good, and I am not sure yet if
  62 it make sense to split different entry types into separate files or
  63 not.  The program is thus likely to change.  If you find it
  64 interesting, please get in touch. :)</p>
  65
  66 <p>As usual, if you use Bitcoin and want to show your support of my
  67 activities, please send Bitcoin donations to my address
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