==========================
Tuesday, February 16, 2016
==========================

I fixed the last failures in the Welfare and Voga test suites.

Replace fabric by invoke
========================

I merged Hamza's work on :ticket:`357` into master.  (`PR 10
<https://github.com/lsaffre/atelier/pull/10>`_) and ran :cmd:`pp` with
:cmd:`fab initdb` and :cmd:`fab test`.  Hamza, note that ``from
__future__`` imports must come *after* the module docstring, otherwise
Sphinx autodoc doesn't see them.

Yes, it seems that we must maintain two documentation strings for
every :cmd:`inv` command. The full documentation in the module's
docstring is integrated in Sphinx, while the task's docstring must be
a single line and without Sphinx markup.  I took :cmd:`inv clean` as
example and adapted the docstring of the task. Compare the description
of :cmd:`inv clean` with the output of :cmd:`inv -l`.  One is the full
user manual, the other is just a summary for the command-line user::

    $ inv -l
    Available tasks:

      blog     Edit today's blog entry, create an empty file if it doesn't yet
               exist.
      ci       Checkin and push to repository, using today's blog entry as commit
      clean    Remove temporary and generated files.
      cov      Run all tests, creating coverage report
      initdb   Run `manage.py initdb_demo` on every demo project.
      mm       Extract messages, then initialize and update all catalogs.
      pd       Publish docs. Upload docs to public web server.
      readme   Generate or update `README.txt` or `README.rst` file from
      reg      Register this project (and its current version) to PyPI.
      test     Run the test suite of this project.


TODO: I have the feeling that the :file:`tasks.py` file can have a
cleaner syntax.


How Lino Voga generates invoices
================================

I started a new tested document :ref:`voga.specs.trading`.

I noticed that enrolments were already invoiceables in
:mod:`lino_xl.lib.courses`.  This was a disturbing design bug since
it introduced a useless field `amount` into the enrolments of Lino
Welfare, and a useless dependency to the 
:mod:`lino_cosi.lib.auto.sales`
plugin.

You might think that the :mod:`lino_xl.lib.courses` module can now
move back to :mod:`lino.modlib` (because it no longer depends on
sales). That's true, but I don't do this now because after
:ticket:`356` it will move to the new "enterprise" or "extended" Lino
library (or however we will call it).

Lots of changes... and finally it seems to work. Checkin.  Short
summary:

I removed the FK field `invoice` on Invoiceable because anyway it was
not used consistently. One invoiceable definitively can create more
than one invoice.

The new subscription courses are actually not subscription *courses*
but enrolment tariffs, i.e. products.
We now have two new fields on Product, `number_of_events` and
`min_asset`.

If `number_of_events` is 0, then it is a "classical" enrolment (one
single invoicing), otherwise it is a "subscription course".  Typical
values are 12 for `number_of_events` and 4 for `min_asset`, which
means that every invoice will pay 12 course events, and after 8 events
the pupil gets a new invoice for the next 12 events.


Printing invoices
=================

And then it was time to work on the template used to print invoices.
Lots of optimizations.
Default build method for Lino Voga is now `wkhtmltopdf`.