zope.app.container 3.5.6

Zope Container

This package define interfaces of container components, and provides sample container implementations such as a BTreeContainer and OrderedContainer.

Detailed Documentation

Containment constraints

Containment constraints allow us to express restrictions on the types of items that can be placed in containers or on the types of containers an item can be placed in. We express these constraints in interfaces. Let’s define some container and item interfaces:

>>> from zope.app.container.interfaces import IContainer, IContained
>>> from zope.app.container.constraints import containers, contains

>>> class IBuddyFolder(IContainer):
...     contains('.IBuddy')

In this example, we used the contains function to declare that objects that provide IBuddyFolder can only contain items that provide IBuddy. Note that we used a string containing a dotted name for the IBuddy interface. This is because IBuddy hasn’t been defined yet. When we define IBuddy, we can use IBuddyFolder directly:

>>> class IBuddy(IContained):
...     containers(IBuddyFolder)

Now, with these interfaces in place, we can define Buddy and BuddyFolder classes and verify that we can put buddies in buddy folders:

>>> from zope import interface

>>> class Buddy:
...     interface.implements(IBuddy)

>>> class BuddyFolder:
...     interface.implements(IBuddyFolder)

>>> from zope.app.container.constraints import checkObject, checkFactory
>>> from zope.component.factory import Factory

>>> checkObject(BuddyFolder(), 'x', Buddy())
>>> checkFactory(BuddyFolder(), 'x', Factory(Buddy))
True

If we try to use other containers or folders, we’ll get errors:

>>> class Container:
...     interface.implements(IContainer)

>>> class Contained:
...     interface.implements(IContained)

>>> checkObject(Container(), 'x', Buddy())
... # doctest: +ELLIPSIS
Traceback (most recent call last):
InvalidContainerType: ...

>>> checkFactory(Container(), 'x', Factory(Buddy))
False

>>> checkObject(BuddyFolder(), 'x', Contained())
... # doctest: +ELLIPSIS
Traceback (most recent call last):
InvalidItemType: ...

>>> checkFactory(BuddyFolder(), 'x', Factory(Contained))
False

In the example, we defined the container first and then the items. We could have defined these in the opposite order:

>>> class IContact(IContained):
...     containers('.IContacts')

>>> class IContacts(IContainer):
...     contains(IContact)

>>> class Contact:
...     interface.implements(IContact)

>>> class Contacts:
...     interface.implements(IContacts)

>>> checkObject(Contacts(), 'x', Contact())

>>> checkFactory(Contacts(), 'x', Factory(Contact))
True

>>> checkObject(Contacts(), 'x', Buddy())
... # doctest: +ELLIPSIS
Traceback (most recent call last):
InvalidItemType: ...

>>> checkFactory(Contacts(), 'x', Factory(Buddy))
False

CHANGES

3.5.6 (2008-08-06)

• no changes. Retag for correct release on PyPI

3.5.5 (2008-07-27)

• Made C code compatible with Python 2.5 on 64bit architectures.

3.5.4 (2008-07-16)

• fixed #238579 / #163149: error with unicode traversing

• fixed #221025adding menu is sorted with translated item

  by using a collator (better localized sorting)

• fixed #227617 :

  • prevent the namechooser from failing on ‘+’, ‘@’ and ‘/’

  • added tests in the namechooser

  • be sure the name chooser returns unicode

• fixed #175388 : the setitem’s size modification is now done in setitemf: setting an existing item does not change the size, and the event subscribers should see the new size instead of the old size. Reimplemented the BTreeContainer so that it directly accesses the btree methods (removed an old #TODO)

3.5.3 (2007-11-09)

• Send IObjectModifiedEvent when changing the title through the @@contents.html view.

  This fixes https://bugs.edge.launchpad.net/zope3/+bug/98483.

3.5.2 (2007-11-01)

• Reactivated functional tests.

3.5.1 (2007-10-31)

• Resolve ZopeSecurityPolicy and IRolePermissionManager deprecation warning.

3.5.0 (2007-10-11)

• Updated package meta-data.

3.5.0a1 (2007-06-29)

• Updated bootstrap script to current version.

• Store length of BTreeContainer in its own Length object for faster __len__ implementation of huge containers.

3.4.0a1 (2007-04-22)

• Initial release as a separate project, corresponds to zope.app.container from Zope 3.4.0a1.