:date: 2019-12-19

===========================
Thursday, December 19, 2019
===========================


Managing addresses
==================

As a user of :ref:`amici` I entered a friend with his address (a :class:`Person
<lino_xl.lib.contacts.Person>` with one :class:`Address
<lino_xl.lib.addresses.Address>`).  Later I also get introduced to his wife.  I
enter her as well, and I register a household (:class:`Household
<lino_xl.lib.households.Household>`) with them as members.  How can I avoid to
enter the address three times?  Answer:

- add his wife as a person and their household without address
- Go to :menuselection:`Explorer --> Contacts --> Addresses`
- Use quick search and filter parameters to find your friend's address
- Change the :attr:`partner <lino_xl.lib.addresses.Address.partner>` of that address from your friend to the household

To make above scenariou work, I had to add filter parameters to the
:class:`lino_xl.lib.addresses.Address` model.

>>> from lino import startup
>>> # startup('lino_book.projects.min9.settings')
>>> startup('lino_amici.projects.herman.settings.demo')
>>> from lino.api.doctest import *
>>> from django.db.models import Q

>>> pprint(rt.models.addresses.Addresses.parameters)
{'address_type': <lino.core.choicelists.ChoiceListField: address_type>,
 'partner': <django.db.models.fields.related.ForeignKey: partner>,
 'place': <django.db.models.fields.related.ForeignKey: place>}

>>> rt.models.addresses.Addresses.params_layout.main
'place partner address_type'


Learning ForeignKey fields
==========================

Until now we had one case of a :term:`learning foreign key` field : the
:attr:`city` field of the address of a
:class:`lino_xl.lib.countries.CountryCity` (e.g. of a partner). When you specify
a country and then discover that the city does not yet exist, you simply leave
the "invalid" city name in the combobox (Lino accepts it) and save the partner.
Lino will then silently create a city of that name.

Now we have a second use case: the :attr:`lino_xl.lib.contacts.Role.person`
field is now learning.  You can see the new feature in every application with
contacts.  For example min1. In the detail of a company, you have the
RolesByCompany slave table. In the Person column of that table you can now type
the name of a person that does not yet exist in the database.  Lino will create
it silently, and you can then click on the pointer to edit more information.


Miscellaneous
=============

Some tests in the book were still failing after my yesterday work. The
:mod:`lino_xl.lib.lists` plugin now supports being used in an application where
:mod:`lino_xl.lib.addresses` is not installed.

The "Diving into Lino" section of the developer guide had an "Introduction" that
contained mostly obsolete nonsense.

The quick search field in the members of a partner list now searches the partner
name. Otherwise it wasn't useful.