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django/tests/multiple_database/routers.py
Loic Bistuer 3a6c37fce4 [1.8.x] Fixed #24351, #24346 -- Changed the signature of allow_migrate().
The new signature enables better support for routing RunPython and
RunSQL operations, especially w.r.t. reusable and third-party apps.

This commit also takes advantage of the deprecation cycle for the old
signature to remove the backward incompatibility introduced in #22583;
RunPython and RunSQL won't call allow_migrate() when when the router
has the old signature.

Thanks Aymeric Augustin and Tim Graham for helping shape up the patch.

Refs 22583.

Conflicts:
	django/db/utils.py

Backport of bed504d70b from master
2015-02-20 21:55:50 +07:00

63 lines
1.9 KiB
Python

from __future__ import unicode_literals
from django.db import DEFAULT_DB_ALIAS
class TestRouter(object):
"""
Vaguely behave like primary/replica, but the databases aren't assumed to
propagate changes.
"""
def db_for_read(self, model, instance=None, **hints):
if instance:
return instance._state.db or 'other'
return 'other'
def db_for_write(self, model, **hints):
return DEFAULT_DB_ALIAS
def allow_relation(self, obj1, obj2, **hints):
return obj1._state.db in ('default', 'other') and obj2._state.db in ('default', 'other')
def allow_migrate(self, db, app_label, **hints):
return True
class AuthRouter(object):
"""
Control all database operations on models in the contrib.auth application.
"""
def db_for_read(self, model, **hints):
"Point all read operations on auth models to 'default'"
if model._meta.app_label == 'auth':
# We use default here to ensure we can tell the difference
# between a read request and a write request for Auth objects
return 'default'
return None
def db_for_write(self, model, **hints):
"Point all operations on auth models to 'other'"
if model._meta.app_label == 'auth':
return 'other'
return None
def allow_relation(self, obj1, obj2, **hints):
"Allow any relation if a model in Auth is involved"
if obj1._meta.app_label == 'auth' or obj2._meta.app_label == 'auth':
return True
return None
def allow_migrate(self, db, app_label, **hints):
"Make sure the auth app only appears on the 'other' db"
if app_label == 'auth':
return db == 'other'
return None
class WriteRouter(object):
# A router that only expresses an opinion on writes
def db_for_write(self, model, **hints):
return 'writer'