def nearest_context_with_adapter(obj, interface, name=u''):
"""Find the nearest adapter in the url chain between obj and interface.
The function looks upward though the canonical url chain and returns a
tuple of (object, adapter).
:return (None, None): if there is no object that has such an adapter
in the url chain.
"""
for current_obj in canonical_url_iterator(obj):
adapter = queryAdapter(current_obj, interface, name=name)
if adapter is not None:
return (current_obj, adapter)
return (None, None)
def nearest_provides_or_adapted(obj, interface):
"""Find the nearest object that provides or can be adapted to `interface`.
The function looks upward through the canonical url chain.
:return None: if there is no object that provides or can be adapted in
the url chain.
"""
try:
for curr_obj in canonical_url_iterator(obj):
# If the curr_obj implements the interface, it is returned.
impl = interface(curr_obj, None)
if impl is not None:
return impl
except NoCanonicalUrl:
# Do not break when canonical URL is not defined for an object.
pass
return None