Fixed #26891 -- Fixed lookup registration for ForeignObject.

This commit is contained in:
Ryan P Kilby 2016-08-11 14:16:48 -04:00 committed by Tim Graham
parent ff0a5aff4f
commit 7aeb7390fc
4 changed files with 81 additions and 35 deletions

View File

@ -1,5 +1,6 @@
from __future__ import unicode_literals
import inspect
import warnings
from functools import partial
@ -17,6 +18,7 @@ from django.utils import six
from django.utils.deprecation import RemovedInDjango20Warning
from django.utils.encoding import force_text
from django.utils.functional import cached_property, curry
from django.utils.lru_cache import lru_cache
from django.utils.translation import ugettext_lazy as _
from django.utils.version import get_docs_version
@ -731,26 +733,13 @@ class ForeignObject(RelatedField):
pathinfos = [PathInfo(from_opts, opts, (opts.pk,), self.remote_field, not self.unique, False)]
return pathinfos
def get_lookup(self, lookup_name):
if lookup_name == 'in':
return RelatedIn
elif lookup_name == 'exact':
return RelatedExact
elif lookup_name == 'gt':
return RelatedGreaterThan
elif lookup_name == 'gte':
return RelatedGreaterThanOrEqual
elif lookup_name == 'lt':
return RelatedLessThan
elif lookup_name == 'lte':
return RelatedLessThanOrEqual
elif lookup_name == 'isnull':
return RelatedIsNull
else:
raise TypeError('Related Field got invalid lookup: %s' % lookup_name)
def get_transform(self, *args, **kwargs):
raise NotImplementedError('Relational fields do not support transforms.')
@classmethod
@lru_cache(maxsize=None)
def get_lookups(cls):
bases = inspect.getmro(cls)
bases = bases[:bases.index(ForeignObject) + 1]
class_lookups = [parent.__dict__.get('class_lookups', {}) for parent in bases]
return cls.merge_dicts(class_lookups)
def contribute_to_class(self, cls, name, private_only=False, **kwargs):
super(ForeignObject, self).contribute_to_class(cls, name, private_only=private_only, **kwargs)
@ -767,6 +756,14 @@ class ForeignObject(RelatedField):
if self.remote_field.limit_choices_to:
cls._meta.related_fkey_lookups.append(self.remote_field.limit_choices_to)
ForeignObject.register_lookup(RelatedIn)
ForeignObject.register_lookup(RelatedExact)
ForeignObject.register_lookup(RelatedLessThan)
ForeignObject.register_lookup(RelatedGreaterThan)
ForeignObject.register_lookup(RelatedGreaterThanOrEqual)
ForeignObject.register_lookup(RelatedLessThanOrEqual)
ForeignObject.register_lookup(RelatedIsNull)
class ForeignKey(ForeignObject):
"""

View File

@ -13,6 +13,7 @@ from collections import namedtuple
from django.core.exceptions import FieldDoesNotExist
from django.db.models.constants import LOOKUP_SEP
from django.utils import tree
from django.utils.lru_cache import lru_cache
# PathInfo is used when converting lookups (fk__somecol). The contents
# describe the relation in Model terms (model Options and Fields for both
@ -27,6 +28,15 @@ class InvalidQuery(Exception):
pass
def subclasses(cls):
yield cls
# Python 2 lacks 'yield from', which could replace the inner loop
for subclass in cls.__subclasses__():
# yield from subclasses(subclass)
for item in subclasses(subclass):
yield item
class QueryWrapper(object):
"""
A type that indicates the contents are an SQL fragment and the associate
@ -132,20 +142,16 @@ class DeferredAttribute(object):
class RegisterLookupMixin(object):
def _get_lookup(self, lookup_name):
try:
return self.class_lookups[lookup_name]
except KeyError:
# To allow for inheritance, check parent class' class_lookups.
for parent in inspect.getmro(self.__class__):
if 'class_lookups' not in parent.__dict__:
continue
if lookup_name in parent.class_lookups:
return parent.class_lookups[lookup_name]
except AttributeError:
# This class didn't have any class_lookups
pass
return None
@classmethod
def _get_lookup(cls, lookup_name):
return cls.get_lookups().get(lookup_name, None)
@classmethod
@lru_cache(maxsize=None)
def get_lookups(cls):
class_lookups = [parent.__dict__.get('class_lookups', {}) for parent in inspect.getmro(cls)]
return cls.merge_dicts(class_lookups)
def get_lookup(self, lookup_name):
from django.db.models.lookups import Lookup
@ -165,6 +171,22 @@ class RegisterLookupMixin(object):
return None
return found
@staticmethod
def merge_dicts(dicts):
"""
Merge dicts in reverse to preference the order of the original list. e.g.,
merge_dicts([a, b]) will preference the keys in 'a' over those in 'b'.
"""
merged = {}
for d in reversed(dicts):
merged.update(d)
return merged
@classmethod
def _clear_cached_lookups(cls):
for subclass in subclasses(cls):
subclass.get_lookups.cache_clear()
@classmethod
def register_lookup(cls, lookup, lookup_name=None):
if lookup_name is None:
@ -172,6 +194,7 @@ class RegisterLookupMixin(object):
if 'class_lookups' not in cls.__dict__:
cls.class_lookups = {}
cls.class_lookups[lookup_name] = lookup
cls._clear_cached_lookups()
return lookup
@classmethod

View File

@ -13,6 +13,10 @@ class Author(models.Model):
return self.name
class Article(models.Model):
author = models.ForeignKey(Author, on_delete=models.CASCADE)
@python_2_unicode_compatible
class MySQLUnixTimestamp(models.Model):
timestamp = models.PositiveIntegerField()

View File

@ -10,7 +10,7 @@ from django.db import connection, models
from django.test import TestCase, override_settings
from django.utils import timezone
from .models import Author, MySQLUnixTimestamp
from .models import Article, Author, MySQLUnixTimestamp
@contextlib.contextmanager
@ -319,6 +319,28 @@ class LookupTests(TestCase):
baseqs.filter(age__div3__range=(1, 2)),
[a1, a2, a4], lambda x: x)
def test_foreignobject_lookup_registration(self):
field = Article._meta.get_field('author')
with register_lookup(models.ForeignObject, Exactly):
self.assertIs(field.get_lookup('exactly'), Exactly)
# ForeignObject should ignore regular Field lookups
with register_lookup(models.Field, Exactly):
self.assertIsNone(field.get_lookup('exactly'))
def test_lookups_caching(self):
field = Article._meta.get_field('author')
# clear and re-cache
field.get_lookups.cache_clear()
self.assertNotIn('exactly', field.get_lookups())
# registration should bust the cache
with register_lookup(models.ForeignObject, Exactly):
# getting the lookups again should re-cache
self.assertIn('exactly', field.get_lookups())
class BilateralTransformTests(TestCase):