An experiment for model fields which automatically do clean() (thus validating the data) when setting values, following the principle of erroring at the earliest opportunity.

I'm hoping this will end up being workable:

from django.db import models
from django.db import fields as nonstrict
import strictmodels as strict

class MyModel(models.Model):
    a = strict.PositiveIntegerField()
    b = nonstrict.PositiveIntegerField()

Note that this model is a combination of strict and normal model fields, which would allow for gradual hardening:

>>> instance = MyModel(a=1, b=2)
>>> instance2 = MyModel(a='test', b=2)
ValidationError: "'test' value must be an integer."

Because a is cleaned on assignment, we receive a handy error, just like with forms. Meanwhile, doing the following would not raise an error, because b is a normal Django field:

>>> instance3 = MyModel(a=1, b='test')

At least not at that point.

Currently, the available fields which have at least some testing, are:

• strictmodels.StrictBigIntegerField (subclasses BigIntegerField)
  • will only allow -9223372036854775808 to 9223372036854775807
• strictmodels.StrictBooleanField (subclasses BooleanField)
• strictmodels.StrictNullBooleanField (subclasses NullBooleanField)
• strictmodels.StrictCharField (subclasses CharField)
• strictmodels.StrictTextField (subclasses TextField)
• strictmodels.StrictCommaSeparatedIntegerField (subclasses CommaSeparatedIntegerField)
• strictmodels.StrictDateField (subclasses DateField)
• strictmodels.StrictDateTimeField (subclasses DateTimeField)
• strictmodels.StrictTimeField (subclasses TimeField)
• strictmodels.StrictDecimalField (subclasses DecimalField)
• strictmodels.StrictEmailField (subclasses EmailField)
  • Will only allow string sequences that pass an emailish regular expression.
• strictmodels.StrictFilePathField (subclasses FilePathField)
  • Will only allow strings whose path is within that set on the field itself.
• strictmodels.StrictFloatField (subclasses FloatField)
• strictmodels.StrictGenericIPAddressField (subclasses GenericIPAddressField)
• strictmodels.StrictIntegerField (subclasses IntegerField)
  • will only allow -2147483648 to 2147483647
• strictmodels.StrictPositiveIntegerField (subclasses PositiveIntegerField)
  • will only allow 0 to 2147483647
• strictmodels.StrictSmallIntegerField (subclasses SmallIntegerField)
  • will only allow -32768 to 32767
• strictmodels.StrictPositiveSmallIntegerField (subclasses PositiveSmallIntegerField)
  • will only allow 0 to 32767
• strictmodels.StrictSlugField (subclasses SlugField)
• strictmodels.StrictURLField (subclasses URLField)

Given a complete clone:

python setup.py test

Or, for a full test:

tox

I'd expect nothing but failure, right now.