Update signature for Django 3

[jrenaut]

Upgrading Django from 2.2 to 3.0.5 and getting this error when I try the built in admin for a model with encrypted fields

TypeError: from_db_value() missing 1 required positional argument: 'context'

Looks like the method signature was updated but someone already has a fix: https://luc.lino-framework.org/blog/2019/1128.html

[coveralls]

Coverage remained the same at 100.0% when pulling b5426bd on jrenaut:master into 8f8cadb on orcasgit:master.

[coveralls]

Coverage remained the same at 100.0% when pulling b5426bd on jrenaut:master into 8f8cadb on orcasgit:master.

[xrmx]

It looks like something specific of the model field you are using, I can't find that parameter in django 2.2, 3.0 and 3.1 branches.

Actually there's a reference in 2.2 and it is that is has been removed in Django 3.0:

contrib/postgres/fields/array.py:            if func_supports_parameter(self.base_field.from_db_value, 'context')  # RemovedInDjango30Warning

[jrenaut]

I think you're right - I upgraded from 0.5 to 0.6 and upgraded a few other outdated packages and it's working now, so I'll close the pull request. I had extended EncryptedField but wasn't doing anything crazy - just needed to encrypt a decimal.

class EncryptedDecimalField(EncryptedField, models.DecimalField):
      pass