===========================
Wednesday, January 28, 2015
===========================

Yesterday's work on :ticket:`80` (Convert Partner to Person) made be
think about The :class:`lino.utils.mti.EnableChild` field. This field
is not really user-friendly. Can't I write something equivalent using
action buttons? A "Polymorphy manager" field. Or should it be
integrated with the polymorphy navigator?

Internal optimizations while experimenting about this:

- The virtual field `mti_navigator` is no longer defined on
  :class:`lino.modlib.contacts.models.Partner` but on
  :class:`lino.mixins.polymorphic.Polymorphic`.

- I finally wrote some actual documentation into the docstrings of
  :class:`DisplayField<lino.core.fields.DisplayField>`,
  :class:`HtmlBox<lino.core.fields.HtmlBox>`,
  :class:`RequestField<lino.core.fields.RequestField>`,
  :class:`VirtualField<lino.core.fields.VirtualField>` etc...

- Some displayfield methods returned a ``<p>`` where a ``<span>`` is
  enough.

- Merged :mod:`lino.core.dbutils` into :mod:`lino.core.utils`.

Result: cool! Lino's MTI navigator now includes buttons for adding and
deleting MTI children.


Getting the Lino docs to build
==============================

I removed the requirement of `sphinxcontrib.taglist
<https://github.com/spinus/sphinxcontrib-taglist>`_ since that module
is no longer maintained.


More about VAT
==============

Congratulations to Mahmoud who contributed `his first pull request
<https://gitlab.com/lino-framework/lino/pull/25>`_.

We then discovered that there are still armies of bugs sitting in the
:mod:`lino.modlib.vat` djungle. And I get the feeling that this is
indeed a job for me. I need to do some more work on this, otherwise
nobody has any chance to understand anything.

.. currentmodule:: lino.modlib.vat

- Renamed `VatRate` to :class:`VatRule`. I plan to move the fields
  `purchases_vat_account` and `sales_vat_account` (which are currently
  in `system.SiteConfig`) to this model as well. Because probably
  there will be users who want Lino to book vat amounts into different
  accounts for different countries. 

- Renamed :meth:`VatRate.find_vat_rate` to
  :meth:`VatRule.get_vat_rule`. It now returns the database object, not
  just the value of the :attr:`VatRule.rate` field.  And there must be
  exactly one row, it now raises a warning instead of returning ZERO.


Commit at 18.00 : 
above changes caused :ref:`cosi` to fail for the moment.
But at least for Lino it should now be possible to build the docs::

  $ go lino
  $ fab initdb test bd


Commit at 23.40 : lots of changes. purchase and sales invoices seem to
work now. demo_bookings no longer generates bank statements because
these seem to not work yet.