61 lines
2.5 KiB
Python
61 lines
2.5 KiB
Python
# -*- coding: utf-8 -*-
|
|
""" PolymorphicManager
|
|
Please see README.rst or DOCS.rst or http://chrisglass.github.com/django_polymorphic/
|
|
"""
|
|
from __future__ import unicode_literals
|
|
import warnings
|
|
import django
|
|
from django.db import models
|
|
from polymorphic.query import PolymorphicQuerySet
|
|
|
|
|
|
class PolymorphicManager(models.Manager):
|
|
"""
|
|
Manager for PolymorphicModel
|
|
|
|
Usually not explicitly needed, except if a custom manager or
|
|
a custom queryset class is to be used.
|
|
"""
|
|
# Tell Django that related fields also need to use this manager:
|
|
use_for_related_fields = True
|
|
queryset_class = PolymorphicQuerySet
|
|
|
|
def __init__(self, queryset_class=None, *args, **kwrags):
|
|
# Up till polymorphic 0.4, the queryset class could be specified as parameter to __init__.
|
|
# However, this doesn't work for related managers which instantiate a new version of this class.
|
|
# Hence, for custom managers the new default is using the 'queryset_class' attribute at class level instead.
|
|
if queryset_class:
|
|
warnings.warn("Using PolymorphicManager(queryset_class=..) is deprecated; override the queryset_class attribute instead", DeprecationWarning)
|
|
# For backwards compatibility, still allow the parameter:
|
|
self.queryset_class = queryset_class
|
|
|
|
super(PolymorphicManager, self).__init__(*args, **kwrags)
|
|
|
|
def get_queryset(self):
|
|
return self.queryset_class(self.model, using=self._db)
|
|
|
|
# For Django 1.5
|
|
if django.VERSION < (1, 7):
|
|
get_query_set = get_queryset
|
|
|
|
if django.VERSION >= (1,6):
|
|
# Should not be used for Django 1.4/1.5 all all, as that breaks the RelatedManager
|
|
def _get_queryset(self):
|
|
return self.get_queryset()
|
|
else:
|
|
# Django 1.5
|
|
def _get_queryset(self):
|
|
return self.get_query_set()
|
|
|
|
# Proxy all unknown method calls to the queryset, so that its members are
|
|
# directly accessible as PolymorphicModel.objects.*
|
|
# The advantage of this method is that not yet known member functions of derived querysets will be proxied as well.
|
|
# We exclude any special functions (__) from this automatic proxying.
|
|
def __getattr__(self, name):
|
|
if name.startswith('__'):
|
|
return super(PolymorphicManager, self).__getattr__(self, name)
|
|
return getattr(self._get_queryset(), name)
|
|
|
|
def __unicode__(self):
|
|
return '%s (PolymorphicManager) using %s' % (self.__class__.__name__, self.queryset_class.__name__)
|