[soc2009/multidb] Switched from using an ugly hacky wrapper to a Metaclass for maitaing backwards compatibility in the get_db_prep_* and db_type methods. Thanks to Jacob for the good idea.

git-svn-id: http://code.djangoproject.com/svn/django/branches/soc2009/multidb@11375 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/management/commands/createcachetable.py

@@ -2,7 +2,6 @@ from optparse import make_option
 
 from django.core.management.base import LabelCommand
 from django.db import connections, transaction, models, DEFAULT_DB_ALIAS
-from django.db.utils import call_with_connection
 
 class Command(LabelCommand):
     help = "Creates the table needed to use the SQL cache backend."
@@ -31,7 +30,7 @@ class Command(LabelCommand):
         index_output = []
         qn = connection.ops.quote_name
         for f in fields:
-            field_output = [qn(f.name), call_with_connection(f.db_type, connection=connection)]
+            field_output = [qn(f.name), f.db_type(connection=connection)]
             field_output.append("%sNULL" % (not f.null and "NOT " or ""))
             if f.primary_key:
                 field_output.append("PRIMARY KEY")

django/core/management/sql.py

@@ -116,7 +116,7 @@ def sql_delete(app, style, connection):
 
 def sql_reset(app, style, connection):
     "Returns a list of the DROP TABLE SQL, then the CREATE TABLE SQL, for the given module."
-    return sql_delete(app, style) + sql_all(app, style)
+    return sql_delete(app, style, connection) + sql_all(app, style, connection)
 
 def sql_flush(style, connection, only_django=False):
     """

django/db/backends/creation.py

@@ -8,7 +8,6 @@ except NameError:
 
 from django.conf import settings
 from django.core.management import call_command
-from django.db.utils import call_with_connection
 
 # The prefix to put on the default database name when creating
 # the test database.
@@ -48,7 +47,7 @@ class BaseDatabaseCreation(object):
         pending_references = {}
         qn = self.connection.ops.quote_name
         for f in opts.local_fields:
-            col_type = call_with_connection(f.db_type, connection=self.connection)
+            col_type = f.db_type(connection=self.connection)
             tablespace = f.db_tablespace or opts.db_tablespace
             if col_type is None:
                 # Skip ManyToManyFields, because they're not represented as
@@ -76,7 +75,7 @@ class BaseDatabaseCreation(object):
             table_output.append(' '.join(field_output))
         if opts.order_with_respect_to:
             table_output.append(style.SQL_FIELD(qn('_order')) + ' ' + \
-                style.SQL_COLTYPE(models.IntegerField().db_type(self.connection)))
+                style.SQL_COLTYPE(models.IntegerField().db_type(connection=self.connection)))
         for field_constraints in opts.unique_together:
             table_output.append(style.SQL_KEYWORD('UNIQUE') + ' (%s)' % \
                 ", ".join([style.SQL_FIELD(qn(opts.get_field(f).column)) for f in field_constraints]))
@@ -174,7 +173,7 @@ class BaseDatabaseCreation(object):
                 style.SQL_TABLE(qn(f.m2m_db_table())) + ' (']
             table_output.append('    %s %s %s%s,' %
                 (style.SQL_FIELD(qn('id')),
-                style.SQL_COLTYPE(models.AutoField(primary_key=True).db_type(self.connection)),
+                style.SQL_COLTYPE(models.AutoField(primary_key=True).db_type(connection=self.connection)),
                 style.SQL_KEYWORD('NOT NULL PRIMARY KEY'),
                 tablespace_sql))
 
@@ -218,14 +217,14 @@ class BaseDatabaseCreation(object):
         table_output = [
             '    %s %s %s %s (%s)%s,' %
                 (style.SQL_FIELD(qn(field.m2m_column_name())),
-                style.SQL_COLTYPE(models.ForeignKey(model).db_type(self.connection)),
+                style.SQL_COLTYPE(models.ForeignKey(model).db_type(connection=self.connection)),
                 style.SQL_KEYWORD('NOT NULL REFERENCES'),
                 style.SQL_TABLE(qn(opts.db_table)),
                 style.SQL_FIELD(qn(opts.pk.column)),
                 self.connection.ops.deferrable_sql()),
             '    %s %s %s %s (%s)%s,' %
                 (style.SQL_FIELD(qn(field.m2m_reverse_name())),
-                style.SQL_COLTYPE(models.ForeignKey(field.rel.to).db_type(self.connection)),
+                style.SQL_COLTYPE(models.ForeignKey(field.rel.to).db_type(connection=self.connection)),
                 style.SQL_KEYWORD('NOT NULL REFERENCES'),
                 style.SQL_TABLE(qn(field.rel.to._meta.db_table)),
                 style.SQL_FIELD(qn(field.rel.to._meta.pk.column)),

django/db/models/base.py

@@ -18,7 +18,6 @@ from django.db.models.options import Options
 from django.db import connections, transaction, DatabaseError, DEFAULT_DB_ALIAS
 from django.db.models import signals
 from django.db.models.loading import register_models, get_model
-from django.db.utils import call_with_connection
 from django.utils.functional import curry
 from django.utils.encoding import smart_str, force_unicode, smart_unicode
 from django.conf import settings
@@ -484,10 +483,10 @@ class Model(object):
                 if not pk_set:
                     if force_update:
                         raise ValueError("Cannot force an update in save() with no primary key.")
-                    values = [(f, call_with_connection(f.get_db_prep_save, raw and getattr(self, f.attname) or f.pre_save(self, True), connection=connection))
+                    values = [(f, f.get_db_prep_save(raw and getattr(self, f.attname) or f.pre_save(self, True), connection=connection))
                         for f in meta.local_fields if not isinstance(f, AutoField)]
                 else:
-                    values = [(f, call_with_connection(f.get_db_prep_save, raw and getattr(self, f.attname) or f.pre_save(self, True), connection=connection))
+                    values = [(f, f.get_db_prep_save(raw and getattr(self, f.attname) or f.pre_save(self, True), connection=connection))
                         for f in meta.local_fields]
 
                 if meta.order_with_respect_to:

django/db/models/fields/__init__.py

@@ -10,8 +10,8 @@ except ImportError:
 
 from django.db import connection
 from django.db.models import signals
+from django.db.models.fields.subclassing import LegacyConnection
 from django.db.models.query_utils import QueryWrapper
-from django.db.utils import call_with_connection
 from django.dispatch import dispatcher
 from django.conf import settings
 from django import forms
@@ -50,6 +50,7 @@ class FieldDoesNotExist(Exception):
 #     getattr(obj, opts.pk.attname)
 
 class Field(object):
+    __metaclass__ = LegacyConnection
     # Designates whether empty strings fundamentally are allowed at the
     # database level.
     empty_strings_allowed = True
@@ -190,8 +191,7 @@ class Field(object):
 
     def get_db_prep_save(self, value, connection):
         "Returns field's value prepared for saving into a database."
-        return call_with_connection(self.get_db_prep_value, value,
-            connection=connection)
+        return self.get_db_prep_value(value, connection=connection)
 
     def get_db_prep_lookup(self, lookup_type, value, connection):
         "Returns field's value prepared for database lookup."
@@ -210,9 +210,9 @@ class Field(object):
         if lookup_type in ('regex', 'iregex', 'month', 'day', 'week_day', 'search'):
             return [value]
         elif lookup_type in ('exact', 'gt', 'gte', 'lt', 'lte'):
-            return [call_with_connection(self.get_db_prep_value, value, connection=connection)]
+            return [self.get_db_prep_value(value, connection=connection)]
         elif lookup_type in ('range', 'in'):
-            return [call_with_connection(self.get_db_prep_value, v, connection=connection) for v in value]
+            return [self.get_db_prep_value(v, connection=connection) for v in value]
         elif lookup_type in ('contains', 'icontains'):
             return ["%%%s%%" % connection.ops.prep_for_like_query(value)]
         elif lookup_type == 'iexact':
@@ -426,8 +426,8 @@ class BooleanField(Field):
         # constructing the list.
         if value in ('1', '0'):
             value = bool(int(value))
-        return call_with_connection(super(BooleanField, self).get_db_prep_lookup,
-            lookup_type, value, connection=connection)
+        return super(BooleanField, self).get_db_prep_lookup(lookup_type, value,
+            connection=connection)
 
     def validate(self, lookup_type, value):
         if super(BooleanField, self).validate(lookup_type, value):
@@ -544,8 +544,8 @@ class DateField(Field):
         # to an int so the database backend always sees a consistent type.
         if lookup_type in ('month', 'day', 'week_day'):
             return [int(value)]
-        return call_with_connection(super(DateField, self).get_db_prep_lookup,
-            lookup_type, value, connection=connection)
+        return super(DateField, self).get_db_prep_lookup(lookup_type, value,
+            connection=connection)
 
     def get_db_prep_value(self, value, connection):
         # Casts dates into the format expected by the backend
@@ -807,8 +807,8 @@ class NullBooleanField(Field):
         # constructing the list.
         if value in ('1', '0'):
             value = bool(int(value))
-        return call_with_connection(super(NullBooleanField, self).get_db_prep_lookup,
-            lookup_type, value, connection=connection)
+        return super(NullBooleanField, self).get_db_prep_lookup(lookup_type,
+            value, connection=connection)
 
     def validate(self, lookup_type, value):
         if value in ('1', '0'):

django/db/models/fields/files.py

@@ -10,7 +10,6 @@ from django.core.files.images import ImageFile, get_image_dimensions
 from django.core.files.uploadedfile import UploadedFile
 from django.utils.functional import curry
 from django.db.models import signals
-from django.db.utils import call_with_connection
 from django.utils.encoding import force_unicode, smart_str
 from django.utils.translation import ugettext_lazy, ugettext as _
 from django import forms
@@ -236,8 +235,8 @@ class FileField(Field):
     def get_db_prep_lookup(self, lookup_type, value, connection):
         if hasattr(value, 'name'):
             value = value.name
-        return call_with_connection(super(FileField, self).get_db_prep_lookup,
-            lookup_type, value, connection=connection)
+        return super(FileField, self).get_db_prep_lookup(lookup_type, value,
+            connection=connection)
 
     def get_db_prep_value(self, value, connection):
         "Returns field's value prepared for saving into a database."

django/db/models/fields/related.py

@@ -5,7 +5,6 @@ from django.db.models.fields import AutoField, Field, IntegerField, PositiveInte
 from django.db.models.related import RelatedObject
 from django.db.models.query import QuerySet
 from django.db.models.query_utils import QueryWrapper
-from django.db.utils import call_with_connection
 from django.utils.encoding import smart_unicode
 from django.utils.translation import ugettext_lazy, string_concat, ungettext, ugettext as _
 from django.utils.functional import curry
@@ -137,8 +136,7 @@ class RelatedField(object):
             if field:
                 if lookup_type in ('range', 'in'):
                     v = [v]
-                v = call_with_connection(field.get_db_prep_lookup,
-                    lookup_type, v, connection=connection)
+                v = field.get_db_prep_lookup(lookup_type, v, connection=connection)
                 if isinstance(v, list):
                     v = v[0]
             return v
@@ -725,8 +723,8 @@ class ForeignKey(RelatedField, Field):
         if value == '' or value == None:
             return None
         else:
-            return call_with_connection(self.rel.get_related_field().get_db_prep_save,
-                value, connection=connection)
+            return self.rel.get_related_field().get_db_prep_save(value,
+                connection=connection)
 
     def value_to_string(self, obj):
         if not obj:
@@ -774,8 +772,8 @@ class ForeignKey(RelatedField, Field):
                 (not connection.features.related_fields_match_type and
                 isinstance(rel_field, (PositiveIntegerField,
                                        PositiveSmallIntegerField)))):
-            return IntegerField().db_type(connection)
-        return call_with_connection(rel_field.db_type, connection=connection)
+            return IntegerField().db_type(connection=connection)
+        return rel_field.db_type(connection=connection)
 
 class OneToOneField(ForeignKey):
     """

django/db/models/fields/subclassing.py

@@ -1,11 +1,48 @@
 """
-Convenience routines for creating non-trivial Field subclasses.
+Convenience routines for creating non-trivial Field subclasses, as well as
+backwards compatibility utilities.
 
 Add SubfieldBase as the __metaclass__ for your Field subclass, implement
 to_python() and the other necessary methods and everything will work seamlessly.
 """
 
-class SubfieldBase(type):
+from inspect import getargspec
+from warnings import warn
+
+def call_with_connection(func):
+    arg_names, varargs, varkwargs, defaults = getargspec(func)
+    takes_connection = 'connection' in arg_names or varkwargs
+    if not takes_connection:
+        warn("A Field class who's %s method doesn't take connection has been "
+            "defined, please add a connection argument" % func.__name__,
+            PendingDeprecationWarning, depth=2)
+    def inner(*args, **kwargs):
+        if 'connection' not in kwargs:
+            from django.db import connection
+            kwargs['connection'] = connection
+            warn("%s has been called without providing a connection argument, "
+                "please provide one" % func.__name__, PendingDeprecationWarning,
+                depth=1)
+        if takes_connection:
+            return func(*args, **kwargs)
+        if 'connection' in kwargs:
+            del kwargs['connection']
+        return func(*args, **kwargs)
+    return inner
+
+class LegacyConnection(type):
+    """
+    A metaclass to normalize arguments give to the get_db_prep_* and db_type
+    methods on fields.
+    """
+    def __new__(cls, names, bases, attrs):
+        new_cls = super(LegacyConnection, cls).__new__(cls, names, bases, attrs)
+        for attr in ('db_type', 'get_db_prep_save', 'get_db_prep_lookup',
+            'get_db_prep_value'):
+            setattr(new_cls, attr, call_with_connection(getattr(new_cls, attr)))
+        return new_cls
+
+class SubfieldBase(LegacyConnection):
     """
     A metaclass for custom Field subclasses. This ensures the model's attribute
     has the descriptor protocol attached to it.
@@ -26,7 +63,7 @@ class Creator(object):
     def __get__(self, obj, type=None):
         if obj is None:
             raise AttributeError('Can only be accessed via an instance.')
-        return obj.__dict__[self.field.name]        
+        return obj.__dict__[self.field.name]
 
     def __set__(self, obj, value):
         obj.__dict__[self.field.name] = self.field.to_python(value)

django/db/models/sql/subqueries.py

@@ -8,7 +8,6 @@ from django.db.models.sql.datastructures import Date
 from django.db.models.sql.expressions import SQLEvaluator
 from django.db.models.sql.query import Query
 from django.db.models.sql.where import AND, Constraint
-from django.db.utils import call_with_connection
 
 __all__ = ['DeleteQuery', 'UpdateQuery', 'InsertQuery', 'DateQuery',
         'AggregateQuery']
@@ -244,8 +243,7 @@ class UpdateQuery(Query):
             if hasattr(val, 'prepare_database_save'):
                 val = val.prepare_database_save(field)
             else:
-                val = call_with_connection(field.get_db_prep_save,
-                    val, connection=self.connection)
+                val = field.get_db_prep_save(val, connection=self.connection)
 
             # Getting the placeholder for the field.
             if hasattr(field, 'get_placeholder'):

django/db/models/sql/where.py

@@ -6,7 +6,6 @@ import datetime
 from django.utils import tree
 from django.db.models.fields import Field
 from django.db.models.query_utils import QueryWrapper
-from django.db.utils import call_with_connection
 from datastructures import EmptyResultSet, FullResultSet
 
 # Connection types
@@ -143,8 +142,8 @@ class WhereNode(tree.Node):
             except EmptyShortCircuit:
                 raise EmptyResultSet
         else:
-            params = call_with_connection(Field().get_db_prep_lookup,
-                lookup_type, params_or_value, connection=connection)
+            params = Field().get_db_prep_lookup(lookup_type, params_or_value,
+                connection=connection)
         if isinstance(lvalue, tuple):
             # A direct database column lookup.
             field_sql = self.sql_for_columns(lvalue, qn, connection)
@@ -267,15 +266,15 @@ class Constraint(object):
         from django.db.models.base import ObjectDoesNotExist
         try:
             if self.field:
-                params = call_with_connection(self.field.get_db_prep_lookup,
-                    lookup_type, value, connection=connection)
-                db_type = call_with_connection(self.field.db_type, connection=connection)
+                params = self.field.get_db_prep_lookup(lookup_type, value,
+                    connection=connection)
+                db_type = self.field.db_type(connection=connection)
             else:
                 # This branch is used at times when we add a comparison to NULL
                 # (we don't really want to waste time looking up the associated
                 # field object at the calling location).
-                params = call_with_connection(Field().get_db_prep_lookup,
-                    lookup_type, value, connection=connection)
+                params = Field().get_db_prep_lookup(lookup_type, value,
+                    connection=connection)
                 db_type = None
         except ObjectDoesNotExist:
             raise EmptyShortCircuit

django/db/utils.py

@@ -32,12 +32,6 @@ def load_backend(backend_name):
             else:
                 raise # If there's some other error, this must be an error in Django itself.
 
-def call_with_connection(func, *args, **kwargs):
-    arg_names, varargs, varkwargs, defaults = inspect.getargspec(func)
-    if 'connection' not in arg_names and varkwargs is None:
-        del kwargs['connection']
-    return func(*args, **kwargs)
-
 
 class ConnectionHandler(object):
     def __init__(self, databases):

django/forms/models.py

@@ -3,7 +3,6 @@ Helper functions for creating Form classes from Django models
 and database field objects.
 """
 
-from django.db.utils import call_with_connection
 from django.utils.encoding import smart_unicode, force_unicode
 from django.utils.datastructures import SortedDict
 from django.utils.text import get_text_list, capfirst
@@ -475,7 +474,7 @@ class BaseModelFormSet(BaseFormSet):
             pk_key = "%s-%s" % (self.add_prefix(i), self.model._meta.pk.name)
             pk = self.data[pk_key]
             pk_field = self.model._meta.pk
-            pk = call_with_connection(pk_field.get_db_prep_lookup, 'exact', pk,
+            pk = pk_field.get_db_prep_lookup('exact', pk,
                 connection=self.get_queryset().query.connection)
             if isinstance(pk, list):
                 pk = pk[0]

tests/regressiontests/model_fields/tests.py

@@ -46,7 +46,7 @@ class DecimalFieldTests(django.test.TestCase):
     def test_get_db_prep_lookup(self):
         from django.db import connection
         f = models.DecimalField(max_digits=5, decimal_places=1)
-        self.assertEqual(f.get_db_prep_lookup('exact', None, connection), [None])
+        self.assertEqual(f.get_db_prep_lookup('exact', None, connection=connection), [None])
 
     def test_filter_with_strings(self):
         """
@@ -100,13 +100,13 @@ class DateTimeFieldTests(unittest.TestCase):
 class BooleanFieldTests(unittest.TestCase):
     def _test_get_db_prep_lookup(self, f):
         from django.db import connection
-        self.assertEqual(f.get_db_prep_lookup('exact', True, connection), [True])
-        self.assertEqual(f.get_db_prep_lookup('exact', '1', connection), [True])
-        self.assertEqual(f.get_db_prep_lookup('exact', 1, connection), [True])
-        self.assertEqual(f.get_db_prep_lookup('exact', False, connection), [False])
-        self.assertEqual(f.get_db_prep_lookup('exact', '0', connection), [False])
-        self.assertEqual(f.get_db_prep_lookup('exact', 0, connection), [False])
-        self.assertEqual(f.get_db_prep_lookup('exact', None, connection), [None])
+        self.assertEqual(f.get_db_prep_lookup('exact', True, connection=connection), [True])
+        self.assertEqual(f.get_db_prep_lookup('exact', '1', connection=connection), [True])
+        self.assertEqual(f.get_db_prep_lookup('exact', 1, connection=connection), [True])
+        self.assertEqual(f.get_db_prep_lookup('exact', False, connection=connection), [False])
+        self.assertEqual(f.get_db_prep_lookup('exact', '0', connection=connection), [False])
+        self.assertEqual(f.get_db_prep_lookup('exact', 0, connection=connection), [False])
+        self.assertEqual(f.get_db_prep_lookup('exact', None, connection=connection), [None])
 
     def test_booleanfield_get_db_prep_lookup(self):
         self._test_get_db_prep_lookup(models.BooleanField())