20131111 (Monday, 11 November 2013)

Lino and Django 1.6

Django 1.6 has been released. Remember from 2013-07-09:

• TODO: lino.core.inject seems to have problems. Which is not too surprising as it uses some subtle but undocumented hacks. Will have a closer look at this when a first release will be visible on PyPI.

lino.core.inject.inject_field didn’t work in Django 1.6: injected fields weren’t seen by subclasses. E.g. lino.modlib.vat injects a field vat_regime to contacts.Partner, but when trying to initdb_demo for Lino Così I got:

File "/home/luc/hgwork/site/djangosite/dbutils.py", line 116, in obj2str
  v = getattr(i,fld.name,None) # 20130709 Django 1.6b1
File "/home/luc/pythonenvs/py27d/local/lib/python2.7/site-packages/django/db/models/fields/subclassing.py", line 32, in __get__
  return obj.__dict__[self.field.name]
KeyError: u"Problem installing fixture '/home/luc/hgwork/lino/lino/modlib/contacts/fixtures/demo.py': u'vat_regime'"

This was because in Django 1.6 the _meta object does a bit more caching of the fields.

Note

Thanks to Kai Willadsen and the authors of the Meld Diff Viewer, a great tool which helped me to understand the above problem.

Another problem is the fact that test discovery has changed. (see Running tests). The Lino test suite happily did things like this:

django-admin.py test --settings=lino.test_apps.quantityfield.settings --noinput --failfast --traceback
django-admin.py test --settings=lino.test_apps.20100212.settings --noinput --failfast --traceback

Before Django 1.6 this worked because tests were only found within packages listed in INSTALLED_APPS. Django 1.6 will discover tests in any file named “test*.py” under the current working directory. So I had adapt most of the tutorials… a rather unpleasant work, but the result is a more straightforward system for maintaining and testing these tutorial apps.

Note

Django sometimes forces you to do things you woulnd’t do on your own, but afterwards you are happy that you did them!