:date: 2020-03-20

======================
Friday, March 20, 2020
======================

For :ref:`presto` we want to add a custom parameter field to the cal.Tasks
table.  This is the moment to convert tasks and events to using the new
:class:`DateRangeObservable` mixin instead of an :class:`ObservedDateRange` for
their :attr:`parameters`.  I created a separate :ticket:`3551` for this.

Also e.g. the `user` field in the parameters is still being specified manually
although this should be done automatically by UserAuthored.

Most of the filters applied in Event.calendar_param_filter are now done by the
mixins (Assignable, ProjectRelated, ...), they are easy cases of
`get_simple_parameters`.

Also comments.Comment can now inherit from DateRangeObservable instead of
reinventing the wheel.

TODO: check how Event.calendar_param_filter now behaves for calview. Because
this is a special case (we want the virtual table row calview.Day to "inherit"
the parameters defined by cal.Event.
I had to move :meth:`setup_parameters` and :meth:`get_simple_parameters`
from Model to TableRow for this.

There is at least one --subtle-- confirmation that this was a good thing.
Visible in :ref:`lino.specs.export_excel`: The title of  cal.MyEntries has
changed from:

  My appointments (Managed by Robin Rood, Dates 01.08.2017 to 31.08.2017)

to:

  My appointments (Responsible user Robin Rood, Dates 01.08.2017 to 31.08.2017)

Indeed the Event.user field is labelled "Responsible user", not "Managed by".

But the most visible advantage is that we have less code now.