CODEWITHSUNDEEP
django
Crazy Frog
Crazy Frog

Reputation: 525

Django - making child class inherit overloaded save method of its parent abstract class

I am newbie in Django and notably its inheritance tools. I have the following architecture:

   class BaseMixin(models.Model):
       effective_from = models.DateTimeField(blank = True, null = True)

       class Meta:
           abstract = True 
   class QuerySetManager(models.Manager):
       def get_queryset(self):
          # ...
       def __getattr__(self, attr, *args):
            return getattr(self.get_queryset(), attr, *args)
       def save(self, *args, **kwargs):
            # I want this method to be deployed for my_model_instance.save()

    class MyModel(BaseMixin):
       # ...
       objects = QuerySetManager()

       class Meta:
           managed = False
           db_table = 'my_model'

       class QuerySet(QuerySet):
           # ...

So my goal is to call QuerySetManager's save method when trying to save changes to my_model_instance. The question is, should I overload save method in BaseMixin ? Or in QuerySetManager ? I tied both, and as for now, Django ignores my custom save method in both cases.

Upvotes: 0

Views: 683

Answers (1)

Bipul Jain
Bipul Jain

Reputation: 4643

Your BaseMixin is abstract class which you are inheriting at other places.

ModelManagers doesn't provide a save method , it's meant for abstracting out complex logic while querying a particular model.

You need to override save MyModel here. Something like. 

class MyModel(BaseMixin):
    # ...
    objects = QuerySetManager()

    class Meta:
        managed = False
        db_table = 'my_model'


    def save(self, force_insert=False, force_update=False, using=None,
         update_fields=None):
        print "In Save Method"
        return super(MyModel, self).save()

Save method is property of model instance.

Simple Example. 

def my_view(request,pk):
    my_model = MyModel.object.get(id=pk)
    my_model.field_1 = "new value"
    ## When you call save method your custom save method is called first.
    my_model.save()

Upvotes: 2

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