def contained(obj, parent=None, name=None):
"""An implementation of zope.app.container.contained.contained
that doesn't generate events, for internal use.
copied from SQLOS / z3c.zalchemy
"""
if (parent is None):
raise TypeError('Must provide a parent')
if not IContained.providedBy(obj):
if ILocation.providedBy(obj):
interface.directlyProvides(obj, IContained,
interface.directlyProvidedBy(obj))
else:
obj = ContainedProxy(obj)
oldparent = obj.__parent__
oldname = obj.__name__
if (oldparent is None) or not (oldparent is parent
or sameProxiedObjects(oldparent, parent)):
obj.__parent__ = parent
if oldname != name and name is not None:
obj.__name__ = name
return obj
def containedEvent(object, container, name=None):
"""Establish the containment of the object in the container
The object and necessary event are returned. The object may be a
`ContainedProxy` around the original object. The event is an added
event, a moved event, or None.
If the object implements `IContained`, simply set its `__parent__`
and `__name__` attributes:
>>> container = {}
>>> item = Contained()
>>> x, event = containedEvent(item, container, u'foo')
>>> x is item
True
>>> item.__parent__ is container
True
>>> item.__name__
u'foo'
We have an added event:
>>> event.__class__.__name__
'ObjectAddedEvent'
>>> event.object is item
True
>>> event.newParent is container
True
>>> event.newName
u'foo'
>>> event.oldParent
>>> event.oldName
Now if we call contained again:
>>> x2, event = containedEvent(item, container, u'foo')
>>> x2 is item
True
>>> item.__parent__ is container
True
>>> item.__name__
u'foo'
We don't get a new added event:
>>> event
If the object already had a parent but the parent or name was
different, we get a moved event:
>>> x, event = containedEvent(item, container, u'foo2')
>>> event.__class__.__name__
'ObjectMovedEvent'
>>> event.object is item
True
>>> event.newParent is container
True
>>> event.newName
u'foo2'
>>> event.oldParent is container
True
>>> event.oldName
u'foo'
If the `object` implements `ILocation`, but not `IContained`, set it's
`__parent__` and `__name__` attributes *and* declare that it
implements `IContained`:
>>> from zope.app.location import Location
>>> item = Location()
>>> IContained.providedBy(item)
False
>>> x, event = containedEvent(item, container, 'foo')
>>> x is item
True
>>> item.__parent__ is container
True
>>> item.__name__
'foo'
>>> IContained.providedBy(item)
True
If the `object` doesn't even implement `ILocation`, put a
`ContainedProxy` around it:
>>> item = []
>>> x, event = containedEvent(item, container, 'foo')
>>> x is item
False
>>> x.__parent__ is container
True
>>> x.__name__
'foo'
Make sure we don't lose existing directly provided interfaces.
>>> from zope.interface import Interface, directlyProvides
>>> class IOther(Interface):
... pass
>>> from zope.app.location import Location
>>> item = Location()
>>> directlyProvides(item, IOther)
>>> IOther.providedBy(item)
True
>>> x, event = containedEvent(item, container, 'foo')
>>> IOther.providedBy(item)
True
"""
if not IContained.providedBy(object):
if ILocation.providedBy(object):
zope.interface.directlyProvides(
object, IContained,
zope.interface.directlyProvidedBy(object))
else:
object = ContainedProxy(object)
oldparent = object.__parent__
oldname = object.__name__
if oldparent is container and oldname == name:
# No events
return object, None
object.__parent__ = container
object.__name__ = name
if oldparent is None or oldname is None:
event = ObjectAddedEvent(object, container, name)
else:
event = ObjectMovedEvent(object, oldparent, oldname, container, name)
return object, event