magic-removal: Refactored method_get_many_to_many and method_set_many_to_many to be methods of Model
git-svn-id: http://code.djangoproject.com/svn/django/branches/magic-removal@1601 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Adrian Holovaty
parent
795ac34f3b
commit
c60ac8f480
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@ -721,20 +721,6 @@ class ModelBase(type):
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for k, v in opts.module_constants.items():
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setattr(new_mod, k, v)
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# Create the default class methods.
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for f in opts.many_to_many:
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# Add "get_thingie" methods for many-to-many related objects.
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# EXAMPLES: Poll.get_site_list(), Story.get_byline_list()
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func = curry(method_get_many_to_many, f)
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func.__doc__ = "Returns a list of associated `%s.%s` objects." % (f.rel.to._meta.app_label, f.rel.to._meta.module_name)
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attrs['get_%s_list' % f.rel.singular] = func
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# Add "set_thingie" methods for many-to-many related objects.
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# EXAMPLES: Poll.set_sites(), Story.set_bylines()
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func = curry(method_set_many_to_many, f)
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func.__doc__ = "Resets this object's `%s.%s` list to the given list of IDs. Note that it doesn't check whether the given IDs are valid." % (f.rel.to._meta.app_label, f.rel.to._meta.module_name)
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func.alters_data = True
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attrs['set_%s' % f.name] = func
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# Create the class, because we need it to use in currying.
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new_class = type.__new__(cls, name, bases, attrs)
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@ -926,6 +912,16 @@ class Model:
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if isinstance(f.rel, ManyToOne):
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setattr(cls, 'get_%s' % f.name, curry(cls.__get_foreign_key_object, field_with_rel=f))
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# Create the default class methods.
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for f in cls._meta.many_to_many:
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# Add "get_thingie" methods for many-to-many related objects.
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# EXAMPLES: Poll.get_site_list(), Story.get_byline_list()
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setattr(cls, 'get_%s_list' % f.rel.singular, curry(cls.__get_many_to_many_objects, field_with_rel=f))
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# Add "set_thingie" methods for many-to-many related objects.
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# EXAMPLES: Poll.set_sites(), Story.set_bylines()
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setattr(cls, 'set_%s' % f.name, curry(cls.__set_many_to_many_objects, field_with_rel=f))
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if cls._meta.order_with_respect_to:
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cls.get_next_in_order = curry(cls.__get_next_or_previous_in_order, is_next=True)
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cls.get_previous_in_order = curry(cls.__get_next_or_previous_in_order, is_next=False)
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@ -1144,6 +1140,59 @@ class Model:
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setattr(self, cache_var, retrieved_obj)
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return getattr(self, cache_var)
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def __get_many_to_many_objects(self, field_with_rel):
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cache_var = '_%s_cache' % field_with_rel.name
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if not hasattr(self, cache_var):
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rel_opts = field_with_rel.rel.to._meta
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sql = "SELECT %s FROM %s a, %s b WHERE a.%s = b.%s AND b.%s = %%s %s" % \
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(','.join(['a.%s' % db.db.quote_name(f.column) for f in rel_opts.fields]),
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db.db.quote_name(rel_opts.db_table),
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db.db.quote_name(field_with_rel.get_m2m_db_table(self._meta)),
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db.db.quote_name(rel_opts.pk.column),
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db.db.quote_name(rel_opts.object_name.lower() + '_id'),
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db.db.quote_name(self._meta.object_name.lower() + '_id'), rel_opts.get_order_sql('a'))
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cursor = db.db.cursor()
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cursor.execute(sql, [getattr(self, self._meta.pk.attname)])
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setattr(self, cache_var, [field_with_rel.rel.to(*row) for row in cursor.fetchall()])
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return getattr(self, cache_var)
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def __set_many_to_many_objects(self, field_with_rel, id_list):
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current_ids = [obj.id for obj in self.__get_many_to_many_objects(field_with_rel)]
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ids_to_add, ids_to_delete = dict([(i, 1) for i in id_list]), []
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for current_id in current_ids:
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if current_id in id_list:
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del ids_to_add[current_id]
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else:
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ids_to_delete.append(current_id)
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ids_to_add = ids_to_add.keys()
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# Now ids_to_add is a list of IDs to add, and ids_to_delete is a list of IDs to delete.
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if not ids_to_delete and not ids_to_add:
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return False # No change
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rel = field_with_rel.rel.to._meta
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m2m_table = field_with_rel.get_m2m_db_table(self._meta)
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cursor = db.db.cursor()
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this_id = getattr(self, self._meta.pk.attname)
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if ids_to_delete:
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sql = "DELETE FROM %s WHERE %s = %%s AND %s IN (%s)" % \
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(db.db.quote_name(m2m_table),
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db.db.quote_name(self._meta.object_name.lower() + '_id'),
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db.db.quote_name(rel.object_name.lower() + '_id'), ','.join(map(str, ids_to_delete)))
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cursor.execute(sql, [this_id])
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if ids_to_add:
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sql = "INSERT INTO %s (%s, %s) VALUES (%%s, %%s)" % \
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(db.db.quote_name(m2m_table),
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db.db.quote_name(self._meta.object_name.lower() + '_id'),
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db.db.quote_name(rel.object_name.lower() + '_id'))
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cursor.executemany(sql, [(this_id, i) for i in ids_to_add])
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db.db.commit()
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try:
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delattr(self, '_%s_cache' % field_with_rel.name) # clear cache, if it exists
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except AttributeError:
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pass
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return True
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__set_many_to_many_objects.alters_data = True
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class Manager:
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def __init__(self, model_class):
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self.klass = model_class
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@ -1334,62 +1383,6 @@ class Manager:
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# RELATIONSHIP METHODS #####################
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# Handles getting many-to-many related objects.
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# Example: Poll.get_site_list()
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def method_get_many_to_many(field_with_rel, self):
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rel = field_with_rel.rel.to
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cache_var = '_%s_cache' % field_with_rel.name
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if not hasattr(self, cache_var):
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mod = rel.get_model_module()
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sql = "SELECT %s FROM %s a, %s b WHERE a.%s = b.%s AND b.%s = %%s %s" % \
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(','.join(['a.%s' % db.db.quote_name(f.column) for f in rel.fields]),
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db.db.quote_name(rel.db_table),
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db.db.quote_name(field_with_rel.get_m2m_db_table(self._meta)),
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db.db.quote_name(rel.pk.column),
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db.db.quote_name(rel.object_name.lower() + '_id'),
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db.db.quote_name(self._meta.object_name.lower() + '_id'), rel.get_order_sql('a'))
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cursor = db.db.cursor()
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cursor.execute(sql, [getattr(self, self._meta.pk.attname)])
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setattr(self, cache_var, [getattr(mod, rel.object_name)(*row) for row in cursor.fetchall()])
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return getattr(self, cache_var)
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# Handles setting many-to-many relationships.
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# Example: Poll.set_sites()
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def method_set_many_to_many(rel_field, self, id_list):
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current_ids = [obj.id for obj in method_get_many_to_many(rel_field, self)]
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ids_to_add, ids_to_delete = dict([(i, 1) for i in id_list]), []
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for current_id in current_ids:
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if current_id in id_list:
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del ids_to_add[current_id]
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else:
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ids_to_delete.append(current_id)
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ids_to_add = ids_to_add.keys()
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# Now ids_to_add is a list of IDs to add, and ids_to_delete is a list of IDs to delete.
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if not ids_to_delete and not ids_to_add:
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return False # No change
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rel = rel_field.rel.to
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m2m_table = rel_field.get_m2m_db_table(self._meta)
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cursor = db.db.cursor()
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this_id = getattr(self, self._meta.pk.attname)
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if ids_to_delete:
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sql = "DELETE FROM %s WHERE %s = %%s AND %s IN (%s)" % \
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(db.db.quote_name(m2m_table),
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db.db.quote_name(self._meta.object_name.lower() + '_id'),
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db.db.quote_name(rel.object_name.lower() + '_id'), ','.join(map(str, ids_to_delete)))
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cursor.execute(sql, [this_id])
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if ids_to_add:
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sql = "INSERT INTO %s (%s, %s) VALUES (%%s, %%s)" % \
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(db.db.quote_name(m2m_table),
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db.db.quote_name(self._meta.object_name.lower() + '_id'),
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db.db.quote_name(rel.object_name.lower() + '_id'))
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cursor.executemany(sql, [(this_id, i) for i in ids_to_add])
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db.db.commit()
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try:
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delattr(self, '_%s_cache' % rel_field.name) # clear cache, if it exists
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except AttributeError:
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pass
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return True
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# Handles related-object retrieval.
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# Examples: Poll.get_choice(), Poll.get_choice_list(), Poll.get_choice_count()
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def method_get_related(method_name, rel_mod, rel_field, self, **kwargs):
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