20110622
========

watch_tim now logs changes
--------------------------

:term:`watch_tim` ruft jetzt :func:`lino.utils.dblogger.log_changes`. 
Dadurch kann man in den log-Dateien nun sehen, was er verändert hat. 
Statt bisher nur der Zusammenfassung "5 changes have been processed."
Checkin-Serie 20110622.


appy.pod and enumerations
-------------------------

Gaëtan has solved the `lists in "do text from xhtml()" <https://bugs.launchpad.net/appy/+bug/777890>`_ problem.
In works on my computer, but when trying it at the customer's 
site I saw another problem::

  Error while evaluating the expression "html(self.body)" defined in the "from" part of a statement.
  File "<string>", line 1, in <module>
  File "/var/snapshots/lino/lino/utils/appy_pod.py", line 63, in html_func
  return renderer.renderXhtml(html,**kw)
  File "/var/snapshots/appy-current/appy/pod/renderer.py", line 238, in renderXhtml
  stylesMapping, ns).run()
  File "/var/snapshots/appy-current/appy/pod/xhtml2odt.py", line 493, in run
  self.xhtmlParser.parse(self.xhtmlString)
  File "/var/snapshots/appy-current/appy/shared/xml_parser.py", line 195, in parse
  self.parser.parse(inputSource)
  File "/usr/lib/python2.6/xml/sax/expatreader.py", line 107, in parse
  xmlreader.IncrementalParser.parse(self, source)
  File "/usr/lib/python2.6/xml/sax/xmlreader.py", line 123, in parse
  self.feed(buffer)
  File "/usr/lib/python2.6/xml/sax/expatreader.py", line 211, in feed
  self._err_handler.fatalError(exc)
  File "/usr/lib/python2.6/xml/sax/handler.py", line 38, in fatalError
  raise exception
  <class 'xml.sax._exceptions.SAXParseException'>: <unknown>:1:1: not well-formed (invalid token)

Here now also a more elegant trick to see the xml fragment 
that causes the problem. In :file:`appy/shared/xml_parser.py` 
I wrapped the `self.parser.parse(inputSource)` call into an 
Exception handler that logs the fragment to the dblogger and 
then re-raises::

  try:
      self.parser.parse(inputSource)
  except Exception,e:
      from lino.utils import dblogger
      dblogger.info("Exception while parsing:-----\n%r\n-----",xml)
      raise
      
This creates the following log entry in the above case::

  201106-22 10:22:44 INFO xml_parser : Exception while parsing:-----
  u'<p><p>In Notizen haben wir jetzt den <strong>WYSIWYG-Editor</strong>.</p>\n<p>Aufz\xe4hlungen sind m\xf6glich:</p>\n<u
  l>\n<li>erstens</li>\n<li>zweitens</li>\n<li>und drittens.\xa0</li>\n</ul>\n<p>Man kann nicht nur <strong>fett</strong>,
   sondern auch <em>kursiv </em>(italic) und <span style="text-decoration: underline;">unterstrichen</span> schreiben.</p>
  \n<p>\xa0</p></p>'
  -----

Explanation: some versions of expat parsers don't like unicode strings.
Always encode them. 
Solution is to have Lino's `html()` template function 
in :mod:`lino.utils.appy_pod` do this::

        if isinstance(html,unicode):
            html = html.encode('utf-8')
            
We simply hardcode UTF-8 because appy.pod currently doesn't support anything else.

Derek Dahmer posted a similar problem on 
`stackoverflow <https://stackoverflow.com/questions/2632111/parsing-unicode-xml-with-python-sax-on-app-engine>`_

Checkin 20110622b.


DoesNotExist at /api/uploads/Uploads
------------------------------------

There was a problem when the owner of an upload no longer exists. 
Deleting a Person obviously does not also delete her uploads, 
and neither does Lino refuse to delete the Person. 
Probably because it is a `GenericForeignKey`. 
But worse: the server afterwards caused an exception 
when we wanted to display a list of all uploads.
This is fixed. And the fields Upload.owner_type and Upload.owner_id are 
now editable again so that users can manually repair such cases.


Kleinkram
---------

- persons_by_user kleine Optimierungen
- Person.get_property
- Funktion `iif` in AppyBuildMethod

Checkin 20110622d.