Login

more on manager methods

Author:
grahamu
Posted:
February 28, 2007
Language:
Python
Version:
Pre .96
Score:
0 (after 0 ratings)

Snippet #2 demonstrated some cool tricks possible with manager methods. This example shows how to assign and use a custom manager method.

In this snippet the belongs_to_user method returns an Account queryset containing only those accounts associated with the specified user. The method is useful because it hides the implementation of User in the Account model.

Line 17 associates the custom manager with the Account model.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
from django.db import models
from django.contrib.auth.models import User

################ models ####################

class AccountManager(models.Manager):
    def belongs_to_user(self, user=None):
        qs = super(type(self), self).get_query_set()
        if user:
            return qs.filter(users__username=user)
        else:
            return qs

class Account(models.Model):
    title = models.CharField(maxlength=30, blank=False)
    users = models.ManyToManyField(User, blank=True, null=True)
    objects = AccountManager()

################ views ####################

def user_accounts(request):
    user_acct_qs = Account.objects.belongs_to_user(request.user.username)

More like this

  1. Template tag - list punctuation for a list of items by shapiromatron 6 months ago
  2. JSONRequestMiddleware adds a .json() method to your HttpRequests by cdcarter 6 months, 1 week ago
  3. Serializer factory with Django Rest Framework by julio 1 year, 1 month ago
  4. Image compression before saving the new model / work with JPG, PNG by Schleidens 1 year, 1 month ago
  5. Help text hyperlinks by sa2812 1 year, 2 months ago

Comments

adurdin (on March 1, 2007):

The first line of belongs_to_user() would be better as:

qs = self.get_query_set()

#

Please login first before commenting.