checks.py 文件源码

def _check_date_hierarchy(self, cls, model):
        """ Check that date_hierarchy refers to DateField or DateTimeField. """

        if cls.date_hierarchy is None:
            return []
        else:
            try:
                field = model._meta.get_field(cls.date_hierarchy)
            except FieldDoesNotExist:
                return refer_to_missing_field(option='date_hierarchy',
                                              field=cls.date_hierarchy,
                                              model=model, obj=cls, id='admin.E127')
            else:
                if not isinstance(field, (models.DateField, models.DateTimeField)):
                    return must_be('a DateField or DateTimeField', option='date_hierarchy',
                                   obj=cls, id='admin.E128')
                else:
                    return []