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magic-removal: Implemented clear() for m2m fields. 

git-svn-id: http://code.djangoproject.com/svn/django/branches/magic-removal@2287 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Luke Plant 2006-02-06 22:27:51 +00:00
parent 28b16af6ca
commit e28addd70b
1 changed files with 27 additions and 1 deletions
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28
django/db/models/fields/related.py
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@ -160,6 +160,19 @@ def _remove_m2m_items(rel_model, join_table, this_col_name,
[this_pk_val, obj._get_pk_val()]) [this_pk_val, obj._get_pk_val()])
connection.commit() connection.commit()
def _clear_m2m_items(join_table, this_col_name, this_pk_val):
# Utility function used by the ManyRelatedObjectsDescriptors
# to clear all from a many-to-many field.
# join_table: name of the m2m link table
# this_col_name: the PK colname in join_table for 'this' object
# this_pk_val: the primary key for 'this' object
from django.db import connection
cursor = connection.cursor()
cursor.execute("DELETE FROM %s WHERE %s = %%s" % \
(join_table, this_col_name),
[this_pk_val])
connection.commit()
class ManyRelatedObjectsDescriptor(object): class ManyRelatedObjectsDescriptor(object):
# This class provides the functionality that makes the related-object # This class provides the functionality that makes the related-object
# managers available as attributes on a model class, for fields that have # managers available as attributes on a model class, for fields that have
@ -203,6 +216,7 @@ class ManyRelatedObjectsDescriptor(object):
_add_m2m_items(self, superclass, rel_model, join_table, this_col_name, _add_m2m_items(self, superclass, rel_model, join_table, this_col_name,
rel_col_name, instance._get_pk_val(), *objs, **kwargs) rel_col_name, instance._get_pk_val(), *objs, **kwargs)
add.alters_data = True add.alters_data = True
if rel_type == "o2m": if rel_type == "o2m":
def remove(self, *objs): def remove(self, *objs):
pass # TODO pass # TODO
@ -212,6 +226,14 @@ class ManyRelatedObjectsDescriptor(object):
rel_col_name, instance._get_pk_val(), *objs) rel_col_name, instance._get_pk_val(), *objs)
remove.alters_data = True remove.alters_data = True
if rel_type == "o2m":
def clear(self):
pass # TODO
else:
def clear(self):
_clear_m2m_items(join_table, this_col_name, instance._get_pk_val())
clear.alters_data = True
manager = RelatedManager() manager = RelatedManager()
if self.rel_type == 'o2m': if self.rel_type == 'o2m':
@ -264,12 +286,16 @@ class ReverseManyRelatedObjectsDescriptor(object):
_add_m2m_items(self, superclass, rel_model, join_table, this_col_name, _add_m2m_items(self, superclass, rel_model, join_table, this_col_name,
rel_col_name, instance._get_pk_val(), *objs, **kwargs) rel_col_name, instance._get_pk_val(), *objs, **kwargs)
add.alters_data = True add.alters_data = True
def remove(self, *objs): def remove(self, *objs):
_remove_m2m_items(rel_model, join_table, this_col_name, _remove_m2m_items(rel_model, join_table, this_col_name,
rel_col_name, instance._get_pk_val(), *objs) rel_col_name, instance._get_pk_val(), *objs)
remove.alters_data = True remove.alters_data = True
def clear(self):
_clear_m2m_items(join_table, this_col_name, instance._get_pk_val())
clear.alters_data = True
manager = RelatedManager() manager = RelatedManager()
manager.model = self.rel_model manager.model = self.rel_model