20120720
========

Printing the Lino version
-------------------------

In a Tx25 it is meaningful to also print the Lino version 
because if a user executes a Tx25, prints it out, then dicovers 
and reports a "missing handler" error, I fix it, 
the user prints it again and zack! we two different documents 
of the same request.
That's not ISO 9002 compatible.
Solution is to always print the Lino version and the date 
of printing.

New method :meth:`lino.Lino.site_header`.

 

KeyError: u'row'
----------------

When an IdentifyPersonRequest has no answer because there were error messages 
(e.g. requests no. 
:srcref:`2 </lino/modlib/cbss/fixtures/demo_ipr_2.xml>`
and
:srcref:`5 </lino/modlib/cbss/fixtures/demo_ipr_5.xml>`
of the demo fixture), then trying to print it causes 
the following traceback::

  201207-17 10:00:14 WARNING ext_ui : Action "Drucken" failed for IdentifyPerson-Anfrage "IdentifyPerson-Anfrage #18":
  u'row'. Ein Fehlerbericht wurde an den Systemverwalter geschickt.
  201207-17 10:00:14 ERROR ext_ui : u'row'
  Traceback (most recent call last):
    File "/var/snapshots/lino/lino/ui/extjs3/ext_ui.py", line 1817, in api_element_view
      rv = a.run(elem,ar)
    File "/var/snapshots/lino/lino/mixins/printable.py", line 595, in run
      bm.build(ar,self,elem)
    File "/var/snapshots/lino/lino/mixins/printable.py", line 274, in build
      return self.simple_build(ar,elem,tplfile,target)
    File "/var/snapshots/lino/lino/mixins/printable.py", line 322, in simple_build
      renderer.run()
    File "/var/snapshots/appy-current/appy/pod/renderer.py", line 350, in run
      self.currentParser.parse(self.contentXml)
    File "/var/snapshots/appy-current/appy/shared/xml_parser.py", line 193, 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 207, in feed
      self._parser.Parse(data, isFinal)
    File "/usr/lib/python2.6/xml/sax/expatreader.py", line 304, in end_element
      self._cont_handler.endElement(name)
    File "/var/snapshots/appy-current/appy/pod/pod_parser.py", line 279, in endElement
      e.currentBuffer.action.execute()
    File "/var/snapshots/appy-current/appy/pod/actions.py", line 76, in execute
      self.do()
    File "/var/snapshots/appy-current/appy/pod/actions.py", line 198, in do
      del context[self.iter]
  KeyError: u'row'  


The document template has the following command::

    do text for row in self.get_result_table(ar)

And `get_result_table` in our case is a generator function that yields no results.

The bug is in `appy.pod.actions.ForAction 
<http://bazaar.launchpad.net/~appy-dev/appy/trunk/view/head:/pod/actions.py>`_::

  class ForAction(BufferAction):
      ...
      def do(self):
          context = self.buffer.env.context
          ...
          for item in self.exprResult:
              context[self.iter] = item
              ...
          if hasHiddenVariable:
              ...
          else:
              if self.exprResult:
                  del context[self.iter]

When `self.exprResult` is an empty iterator, the above traceback will occur.
Discovered that I had already posted this bug to 
the `appy forum <https://bugs.launchpad.net/appy/+bug/897755>`_.
Applied my own workaround described there::

    do text for row in list/self.get_result_table(ar))

Posted my suggestion for a solution.

Miscellaneous
-------------

Acting as another user will not give you the access permissions of that user.
A secretary who has authority to act as her boss in order to manage his calendar
should not also see e.g. statistic reports to which she has no access.
New exception to this rule:
For system admins it is different: 
when a system admin acts as another user, 
he inherits this user's access permissions. 
System admins use this feature to test the permissions of other users.