magic-removal: Implemented adding many-to-many objects -- obj.sites.add() instead of obj.set_sites()

git-svn-id: http://code.djangoproject.com/svn/django/branches/magic-removal@2255 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/base.py

@@ -357,43 +357,6 @@ class Model(object):
             setattr(self, cachename, get_image_dimensions(filename))
         return getattr(self, cachename)
 
-    def _set_many_to_many_objects(self, id_list, field_with_rel):
-        current_ids = [obj._get_pk_val() for obj in self._get_many_to_many_objects(field_with_rel)]
-        ids_to_add, ids_to_delete = dict([(i, 1) for i in id_list]), []
-        for current_id in current_ids:
-            if current_id in id_list:
-                del ids_to_add[current_id]
-            else:
-                ids_to_delete.append(current_id)
-        ids_to_add = ids_to_add.keys()
-        # Now ids_to_add is a list of IDs to add, and ids_to_delete is a list of IDs to delete.
-        if not ids_to_delete and not ids_to_add:
-            return False # No change
-        rel = field_with_rel.rel.to._meta
-        m2m_table = field_with_rel.get_m2m_db_table(self._meta)
-        cursor = connection.cursor()
-        this_id = self._get_pk_val()
-        if ids_to_delete:
-            sql = "DELETE FROM %s WHERE %s = %%s AND %s IN (%s)" % \
-                (backend.quote_name(m2m_table),
-                backend.quote_name(self._meta.object_name.lower() + '_id'),
-                backend.quote_name(rel.object_name.lower() + '_id'), ','.join(map(str, ids_to_delete)))
-            cursor.execute(sql, [this_id])
-        if ids_to_add:
-            sql = "INSERT INTO %s (%s, %s) VALUES (%%s, %%s)" % \
-                (backend.quote_name(m2m_table),
-                backend.quote_name(self._meta.object_name.lower() + '_id'),
-                backend.quote_name(rel.object_name.lower() + '_id'))
-            cursor.executemany(sql, [(this_id, i) for i in ids_to_add])
-        connection.commit()
-        try:
-            delattr(self, '_%s_cache' % field_with_rel.name) # clear cache, if it exists
-        except AttributeError:
-            pass
-        return True
-
-    _set_many_to_many_objects.alters_data = True
-
     # Handles setting many-to-many related objects.
     # Example: Album.set_songs()
     def _set_related_many_to_many(self, rel_class, rel_field, id_list):

django/db/models/fields/related.py

@@ -1,4 +1,4 @@
-from django.db import backend
+from django.db import backend, connection
 from django.db.models import signals
 from django.db.models.fields import AutoField, Field, IntegerField
 from django.db.models.related import RelatedObject
@@ -117,6 +117,7 @@ class ManyRelatedObjectsDescriptor(object):
             def add(self, **kwargs):
                 kwargs.update({rel_field.name: instance})
                 return superclass.add(self, **kwargs)
+            add.alters_data = True
 
         manager = RelatedManager()
 
@@ -151,8 +152,11 @@ class ReverseManyRelatedObjectsDescriptor(object):
 
         qn = backend.quote_name
         this_opts = instance.__class__._meta
+        rel_model = self.rel_model
         rel_opts = self.rel_model._meta
         join_table = backend.quote_name(self.field.get_m2m_db_table(this_opts))
+        this_col_name = this_opts.object_name.lower() + '_id'
+        rel_col_name = rel_opts.object_name.lower() + '_id'
 
         # Dynamically create a class that subclasses the related
         # model's default manager.
@@ -163,11 +167,31 @@ class ReverseManyRelatedObjectsDescriptor(object):
                 return superclass.get_query_set(self).extra(
                     tables=(join_table,),
                     where=[
-                        '%s.%s = %s.%s' % (qn(rel_opts.db_table), qn(rel_opts.pk.column), join_table, rel_opts.object_name.lower() + '_id'),
-                        '%s.%s = %%s' % (join_table, this_opts.object_name.lower() + '_id')
+                        '%s.%s = %s.%s' % (qn(rel_opts.db_table), qn(rel_opts.pk.column), join_table, rel_col_name),
+                        '%s.%s = %%s' % (join_table, this_col_name)
                     ],
                     params = [instance._get_pk_val()]
                 )
+            def add(self, *objs, **kwargs):
+                from django.db import connection
+                # Create the related object.
+                if kwargs:
+                    assert len(objs) == 0, "add() can't be passed both positional and keyword arguments"
+                    objs = [superclass.add(self, **kwargs)]
+                else:
+                    assert len(objs) > 0, "add() must be passed either positional or keyword arguments"
+                    for obj in objs:
+                        if not isinstance(obj, rel_model):
+                            raise ValueError, "positional arguments to add() must be %s instances" % rel_opts.object_name
+                # Add the newly created object to the join table.
+                # TODO: Check to make sure the object isn't already in the join table.
+                cursor = connection.cursor()
+                for obj in objs:
+                    cursor.execute("INSERT INTO %s (%s, %s) VALUES (%%s, %%s)" % \
+                        (join_table, this_col_name, rel_col_name),
+                        [instance._get_pk_val(), obj._get_pk_val()])
+                connection.commit()
+            add.alters_data = True
 
         manager = RelatedManager()
 
@@ -384,10 +408,6 @@ class ManyToManyField(RelatedField, Field):
         super(ManyToManyField, self).contribute_to_class(cls, name)
         setattr(cls, self.name, ReverseManyRelatedObjectsDescriptor(self))
 
-        # Add "set_thingie" methods for many-to-many related objects.
-        # EXAMPLES: Poll.set_sites(), Story.set_bylines()
-        setattr(cls, 'set_%s' % self.name, curry(cls._set_many_to_many_objects, field_with_rel=self))
-
     def contribute_to_related_class(self, cls, related):
         setattr(cls, related.get_accessor_name(), ManyRelatedObjectsDescriptor(related, 'm2m'))
         self.rel.singular = self.rel.singular or self.rel.to._meta.object_name.lower()