# Thursday, August 20, 2015¶

I worked 5 hours on ticket #38 (Make Lino run with Django 1.8).

Until yesterday I believed that this is a good ticket for Mahmoud, but for the moment I changed my mind. This is not for beginners since it requires quite some knowledge of the dragons living in Lino. The challenge is Django’s new application loading system. Augustin and I have been working on this in parallel, and of course our solutions differ slightly.

I renamed lino.modlib.contenttypes to lino.modlib.gfks. So this plugin no longer extends django.contrib.contenttypes, it just causes depends on it (lino.core.site.Site.needs_plugins). This is because Django 1.9 will refuse to import a database model which is neither abstract nor actually being used:

RemovedInDjango19Warning: Model class
django.contrib.contenttypes.models.ContentType doesn't declare an
explicit app_label and either isn't in an application in
INSTALLED_APPS or else was imported before its application was
loaded. This will no longer be supported in Django 1.9.


So in Django 1.9 we cannot extend plain Django plugins like django.contrib.contenttypes. That’s okay, and contenttypes was the only case. Anyway the idea of extending it using the same name was a bit hackerish. You can use plugins designed for plain Django in Lino, but you cannot extend them.

Diamond inheritance still causes problems. My workaround works only until Django 1.6 and I did not yet get it to work in Django > 1.6. It is visible in lino.projects.min2:

$go min2$ python manage.py initdb_demo
...
django.core.management.base.SystemCheckError: SystemCheckError: System check identified some issues:

ERRORS:
contacts.Company.addr1: (models.E006) The field 'addr1' clashes with the field 'addr1' from model 'contacts.partner'.
contacts.Company.addr2: (models.E006) The field 'addr2' clashes with the field 'addr2' from model 'contacts.partner'.
contacts.Company.city: (models.E006) The field 'city' clashes with the field 'city' from model 'contacts.partner'.
contacts.Company.country: (models.E006) The field 'country' clashes with the field 'country' from model 'contacts.partner'.
contacts.Company.email: (models.E006) The field 'email' clashes with the field 'email' from model 'contacts.partner'.
contacts.Company.fax: (models.E006) The field 'fax' clashes with the field 'fax' from model 'contacts.partner'.
contacts.Company.gsm: (models.E006) The field 'gsm' clashes with the field 'gsm' from model 'contacts.partner'.
contacts.Company.language: (models.E006) The field 'language' clashes with the field 'language' from model 'contacts.partner'.
contacts.Company.name: (models.E006) The field 'name' clashes with the field 'name' from model 'contacts.partner'.
contacts.Company.phone: (models.E006) The field 'phone' clashes with the field 'phone' from model 'contacts.partner'.
contacts.Company.region: (models.E006) The field 'region' clashes with the field 'region' from model 'contacts.partner'.
contacts.Company.remarks: (models.E006) The field 'remarks' clashes with the field 'remarks' from model 'contacts.partner'.
contacts.Company.street: (models.E006) The field 'street' clashes with the field 'street' from model 'contacts.partner'.
contacts.Company.street_box: (models.E006) The field 'street_box' clashes with the field 'street_box' from model 'contacts.partner'.
contacts.Company.street_no: (models.E006) The field 'street_no' clashes with the field 'street_no' from model 'contacts.partner'.
contacts.Company.street_prefix: (models.E006) The field 'street_prefix' clashes with the field 'street_prefix' from model 'contacts.partner'.
contacts.Company.url: (models.E006) The field 'url' clashes with the field 'url' from model 'contacts.partner'.
contacts.Company.zip_code: (models.E006) The field 'zip_code' clashes with the field 'zip_code' from model 'contacts.partner'.
contacts.Person.addr1: (models.E006) The field 'addr1' clashes with the field 'addr1' from model 'contacts.partner'.
contacts.Person.addr2: (models.E006) The field 'addr2' clashes with the field 'addr2' from model 'contacts.partner'.
contacts.Person.city: (models.E006) The field 'city' clashes with the field 'city' from model 'contacts.partner'.
contacts.Person.country: (models.E006) The field 'country' clashes with the field 'country' from model 'contacts.partner'.
contacts.Person.email: (models.E006) The field 'email' clashes with the field 'email' from model 'contacts.partner'.
contacts.Person.fax: (models.E006) The field 'fax' clashes with the field 'fax' from model 'contacts.partner'.
contacts.Person.gsm: (models.E006) The field 'gsm' clashes with the field 'gsm' from model 'contacts.partner'.
contacts.Person.language: (models.E006) The field 'language' clashes with the field 'language' from model 'contacts.partner'.
contacts.Person.name: (models.E006) The field 'name' clashes with the field 'name' from model 'contacts.partner'.
contacts.Person.phone: (models.E006) The field 'phone' clashes with the field 'phone' from model 'contacts.partner'.
contacts.Person.region: (models.E006) The field 'region' clashes with the field 'region' from model 'contacts.partner'.
contacts.Person.remarks: (models.E006) The field 'remarks' clashes with the field 'remarks' from model 'contacts.partner'.
contacts.Person.street: (models.E006) The field 'street' clashes with the field 'street' from model 'contacts.partner'.
contacts.Person.street_box: (models.E006) The field 'street_box' clashes with the field 'street_box' from model 'contacts.partner'.
contacts.Person.street_no: (models.E006) The field 'street_no' clashes with the field 'street_no' from model 'contacts.partner'.
contacts.Person.street_prefix: (models.E006) The field 'street_prefix' clashes with the field 'street_prefix' from model 'contacts.partner'.
contacts.Person.url: (models.E006) The field 'url' clashes with the field 'url' from model 'contacts.partner'.
contacts.Person.zip_code: (models.E006) The field 'zip_code' clashes with the field 'zip_code' from model 'contacts.partner'.


IOW these are the fields defined in the AddressLocation mixin, inherited by the abstract Partner and Person models of lino.modlib.contacts, which are then themselves inherited by Partner and Person in lino.projects.min2.modlib.contacts.

The following diagram shows the structure for Person (for Company it is analog):