:date: 2017-01-29

========================
Sunday, January 29, 2017
========================

I returned back to using both subject and body in notification
messages.  This is part of :ticket:`1322`. I had removed the `subject`
sometime in December 2016 because I thought that it is more clean to
think about notifications as "one message to be sent to one user", and
that the distinction between "subject" and "body" was nonsense for
notifications. But it isn't: we need it e.g. when sending
notifications as individual emails, or in grids where we want a quick
overview of all notifications. only the application code.

These changes caused some failures in
:file:`lino_welfare/projects/std/tests/test_notify.py` when it calls
the checkin action on a Guest (i.e. an instance of CheckinVisitor
which inherits from NotifyingAction)::

        res = ses.run(guest.checkin)
        self.assertEqual(res, {
            'message': '', 'success': True, 'refresh': True})

        # it has caused a notification message:
        self.assertEqual(Message.objects.count(), 1)

That test had passed until now, but this was wrong because the checkin
action should not return an empty message.

This revealed a subtle bug which I called :ticket:`1440`.  It is about
parameter actions, i.e. actions which have a dialog window to be
displayed before running the action.  The :meth:`action_param_values
<lino.core.actions.Action.action_param_values>` method of these
actions is expected to return the default values for the parameters of
the dialog window.  When it is called, it is given the object on which
it is being called. This object was `None` here.  I added a new
keyword argument `selected_rows` to :meth:`BaseRequest.setup`.

This bug is maybe related to :ticket:`1366`.

Fixing this bug required also a change in lino.modlib.extjs which I
did in ext6 as well.


Upgrade on :ref:`lf`
====================

A routine upgrade, mostly in order to test whether my yesterday's
changes didn't introduce any regression.

This is a quick routine upgrade. There are no release notes. But an
important question in this situation is "Do I need to run a migration?
Were there any changes since last time which require a database
migration?".

We are Sunday evening and you might threaten to kill me, I still would
not be able to say when was our last upgrade on that site or whether I
did some changes to the database schema of :ref:`noi` since that
moment.

The important thing to not forget is to make a snapshot of your
database before pulling the new sources.

The trick for quickly testing whether you need to restore the snapshot
is to run a temporary dump::


  $ python manage.py dump2py t -o

This time it gave me the following error message::  

  django.db.utils.OperationalError: (1054, "Unknown column 'changes_change.changed_fields' in 'field list'")

Yes, of course. Now I remember that I added that field.

Usually this simply means that You now must restore your snapshot::

  $ python manage.py run snapshots/restore.py

Voilà.

And then I adapted
:meth:`lino.modlib.comments.models.Comment.get_change_subject` and
:meth:`lino.modlib.notify.models.Message.send_summary_emails` so that
the subject of emails are now more meaningful: "Luc commented on #1440
(...)" is a more meaningful subject than "You have 1 notifications".