django-xvalidate 0.2.0

Cross-field validators within a Django model

django-xvalidate allows you to declare cross-field validators within a Django model.

As an example, consider a Django model named Event.

from django.db import models

class Event(models.Model):
    title = models.CharField(max_length=255)
    start_date = models.DateField()
    end_date = models.DateField()

django-xvalidate allows you to declare that the start date precedes the end date as follows:

from django.db import models
from xvalidate import XValidatedModel, XLe

class Event(XValidatedModel, models.Model):
    title = models.CharField(max_length=255)
    start_date = models.DateField()
    end_date = models.DateField()

    class XVMeta(XValidatedModel.XVMeta):
        spec = [
            XLe('start_date', 'end_date',
                message='The start date should precede the end date')
        ]

XValidatedModel ensures that this specification is maintained invoking Event.clean() and raises ValidationError as appropriate.