def unrelateOnCopy(event):
"""Remove all relationships when an object is copied."""
if not IObjectCopiedEvent.providedBy(event):
return
# event.object may be a ContainedProxy
obj = getProxiedObject(event.object)
linkset = IRelationshipLinks(obj, None)
if linkset is not None:
links_to_remove = []
for link in linkset:
other_linkset = IRelationshipLinks(link.target)
try:
other_linkset.find(link.role, obj, link.my_role, link.rel_type)
except ValueError:
# The corresponding other link was not copied, so we have a
# degenerate one-sided relationship. Let's remove it
# altogether. It would not difficult to have a different
# function, cloneRelationshipsOnCopy, that would create
# a corresponding link in other_linkset.
links_to_remove.append(link)
for link in links_to_remove:
linkset.remove(link)
def unrelate(rel_type, (a, role_of_a), (b, role_of_b)):
"""Break a relationship between objects `a` and `b`."""
links_of_a = IRelationshipLinks(a)
links_of_b = IRelationshipLinks(b)
try:
link_a_to_b = links_of_a.find(role_of_a, b, role_of_b, rel_type)
except ValueError:
raise NoSuchRelationship
extra_info = link_a_to_b.extra_info
zope.event.notify(BeforeRemovingRelationshipEvent(rel_type,
(a, role_of_a),
(b, role_of_b),
extra_info))
links_of_a.remove(link_a_to_b)
# If links_of_b.find raises a ValueError, our data structures are out of
# sync.
link_b_to_a = links_of_b.find(role_of_b, a, role_of_a, rel_type)
links_of_b.remove(link_b_to_a)
zope.event.notify(RelationshipRemovedEvent(rel_type,
(a, role_of_a),
(b, role_of_b),
extra_info))
def unrelateAll(obj):
"""Break all relationships of `obj`.
Note that this operation is not atomic: if an event subscriber catches
a BeforeRemovingRelationshipEvent and vetoes the operation, some
(link.target, link.role), shared))
def unrelate(rel_type, (a, role_of_a), (b, role_of_b)):
"""Break a relationship between objects `a` and `b`."""
links_of_a = IRelationshipLinks(a)
links_of_b = IRelationshipLinks(b)
try:
link_a_to_b = links_of_a.find(role_of_a, b, role_of_b, rel_type)
except ValueError:
raise NoSuchRelationship
extra_info = link_a_to_b.extra_info
zope.event.notify(
BeforeRemovingRelationshipEvent(rel_type, (a, role_of_a),
(b, role_of_b), extra_info))
links_of_a.remove(link_a_to_b)
# If links_of_b.find raises a ValueError, our data structures are out of
# sync.
link_b_to_a = links_of_b.find(role_of_b, a, role_of_a, rel_type)
links_of_b.remove(link_b_to_a)
zope.event.notify(
RelationshipRemovedEvent(rel_type, (a, role_of_a), (b, role_of_b),
extra_info))
def unrelateAll(obj):
"""Break all relationships of `obj`.
Note that this operation is not atomic: if an event subscriber catches
a BeforeRemovingRelationshipEvent and vetoes the operation, some
relationships may have been removed, while others may still be there.
