20110713
========


The :mod:`lino_xl.lib.cal` module is growing
--------------------------------------------

What are "automatic tasks"? 
If a Person has a non-empty `unavailable_until` field, 
Lino will create an automatic task 
"becomes available again" for that Person and the responsible user 
on that date, with an alarm set 1 month before.

Before the :mod:`lino_xl.lib.cal` module, Lino knew 
only automatic tasks. 

Currently there are three models which create "automatic tasks":
Person, Note and Contract. 
(Where Note and Contract mostly inherit the corresponding behaviour from :class:`lino.mixins.Reminder`)

This is implemented by overriding 
their `save` method.

I think I'm going to do the following relationships for the 
:mod:`lino_xl.lib.cal` module:

.. digraph:: foo

    "Note" -> "Task"
    "Note" -> "Person" 
    "Note" -> "Company" 
    
    "Task" -> "Person"
    "Task" -> "Company"
    
    "Note" -> "Event"
    "Event" -> "Person" 
    "Event" -> "Company" 
    
    
This leads to the following slave reports: 

  - Notes : by Company, by Person, by Event
  - Tasks : by Company, by Person
  - Events : by Company, by Person, by Task
  
  
`owner` field of :class:`lino.mixins.Owned` now nullable
--------------------------------------------------------

The `owner_type` and `owner_id` fields of 
a :class:`lino.mixins.Owned` are now nullable.
This is necessary for :class:`lino_xl.lib.cal.Task` 
and probably doesn't disturb for other cases 
(that is, Upload and Third).

Toggle CheckColumns from a grid
-------------------------------

It is now again possible to toggle a CheckColumn simply by clicking on it.
I'd prefer doubleclick for that, but it seems that a doubleclick never 
reaches the CheckColuimn component (I guess because it gets consumed by the row).

Displaying GenericForeignKey in a Grid
--------------------------------------

New :class:`lino.fields.GenericForeignKeyIdField` is used by `lino.ui.extjs3` 
to handle the correct store field type for these fields.
the `owner_id` field of :class:`lino.mixins.Owned` is currently the only usecase.


Checkin 20110713