# Thursday, May 12, 2016¶

I worked on #910 : a course (in Lino Voga) now has an “Export” button which generates and opens an xlsx file designed to be printed on paper for manually noting the presences of participants.

This document has a special challenge: when there are more than 20 events (or some configurable maximum number), then colums don’t fit on a single page, and in that case it is necessary to split the document vertically, i.e. print remaining columns to a second page (or set of pages, if there are many participants).

I believe that the first implementation using wkhtmltopdf had no future because wkhtmltopdf fails fundamentally with defining page headers and footers.

This is also a new style of build method for printables: it has a target file to be generated and rendered to the request, but does not use any template at all. This is CustomBuildMethod.

Also TIL that xlwt has been replaced by openpyxl.

We had a case of AttributeError: ‘NoneType’ object has no attribute ‘number_of_events’:

File "/lino_voga/lib/courses/models.py", line 257, in __init__
if obj.product.number_of_events:


Alexa reported another subtle use case which I classify as part of #909:

Im Kurs 001 sind Leute eingeschrieben, die in ein paar Tagen beginnen. Also Startdatum steht auf 17. Mai. Lino zeigt aber am Bildschirm an (und druckt im Belegstatus aus), dass diese Plätze noch frei sind. Wenn sich heute noch jemand anmeldet, dann sehen wir nicht, dass der Kurs schon voll ist.

I fixed it and wrote some test cases into Activities in Lino Voga. To get these test cases I had to enhance the demo fixture (lino_voga.lib.voga.fixtures.buche).

I did something which I should have done eariler: I changed the default English date formatting done by lino.utils.date_format from US to UK. This causes of course lots of changes in doctests. But it is just too impossible to get used to the American date format.