The Java Jester

Base Class For My Entities

Here is the base class of my entities. This one supports deleting of record by marking instead of permanently deleting the record:

class BaseModel(models.Model):
    """
    Base model for all entities
    """

    date_created = models.DateTimeField(auto_now_add=True)
    date_updated = models.DateTimeField(auto_now=True, auto_now_add=True)

    def delete(self, permanent=False):
        """
        Delete a model by flagging. An optional parameter 'permanent' can be passed to permanently delete it
        """
        if BaseModel.__deletable_type(self.__class__) and not permanent:
            self.deleted = 1
            self.save()
        else:
            models.Model.delete(self)

    @classmethod
    def all(cls, include_deleted=False):
        """
        Get all query object with deleted records filtered
        """
        deleted_field = hasattr(cls, "deleted")
        if BaseModel.__deletable_type(cls) and not include_deleted:
            query = cls.objects.all()
            return query.filter(deleted=False)
        else:
            return cls.objects.all()

    @classmethod
    def __deletable_type(cls, input_cls):
        """
        Check if this class is deletable by flagging. The algorithm is slow so it needs some tweaking later
        """
        for b in input_cls.__bases__:
            if b.__name__ == 'BaseDeletableUserModel': return True
        return False

    class Meta:
        abstract = True

class BaseDeletableModel(BaseModel):
    """
    A deletable base model
    """

    deleted = models.BooleanField(default=False)

    class Meta:
        abstract = True