Created
February 25, 2013 08:01
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Singleton Django Model
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# Written by Senko Rasic <[email protected]> | |
# Released into Public Domain. Use it as you like. | |
from django.db import models | |
class SingletonModel(models.Model): | |
"""Singleton Django Model | |
Ensures there's always only one entry in the database, and can fix the | |
table (by deleting extra entries) even if added via another mechanism. | |
Also has a static load() method which always returns the object - from | |
the database if possible, or a new empty (default) instance if the | |
database is still empty. If your instance has sane defaults (recommended), | |
you can use it immediately without worrying if it was saved to the | |
database or not. | |
Useful for things like system-wide user-editable settings. | |
""" | |
class Meta: | |
abstract = True | |
def save(self, *args, **kwargs): | |
""" | |
Save object to the database. Removes all other entries if there | |
are any. | |
""" | |
self.__class__.objects.exclude(id=self.id).delete() | |
super(SingletonModel, self).save(*args, **kwargs) | |
@classmethod | |
def load(cls): | |
""" | |
Load object from the database. Failing that, create a new empty | |
(default) instance of the object and return it (without saving it | |
to the database). | |
""" | |
try: | |
return cls.objects.get() | |
except cls.DoesNotExist: | |
return cls() |
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Is this still supported by django?