[Zope3-checkins] CVS: Zope3/src/zope/app/event - subs.py:1.10

[Steve Alexander]

Update of /cvs-repository/Zope3/src/zope/app/event
In directory cvs.zope.org:/tmp/cvs-serv5632/src/zope/app/event

Modified Files:
	subs.py 
Log Message:
Fixed bug in event service where it was subscribing three times
to its parent event service. This was revealed by a unit test when the
erroneous 'Subscriptions' service id was replaced with the symbolic
constant. One bug had hidden the other. Symbolic service names are a
good idea.


=== Zope3/src/zope/app/event/subs.py 1.9 => 1.10 ===
--- Zope3/src/zope/app/event/subs.py:1.9	Mon Feb 17 13:22:02 2003
+++ Zope3/src/zope/app/event/subs.py	Tue Feb 18 10:19:22 2003
@@ -32,7 +32,7 @@
 from zope.app.interfaces.event import IEvent, ISubscriber, ISubscribable
 from zope.app.interfaces.event import ISubscribingAware
 
-from zope.component import getService, getAdapter, queryAdapter
+from zope.component import getService, queryService, getAdapter, queryAdapter
 from zope.component import ComponentLookupError
 from zope.app.services.servicenames import HubIds
 from zope.app.services.type import PersistentTypeRegistry
@@ -79,13 +79,19 @@
         if not event_type.extends(IEvent, strict=False):
             raise TypeError('event_type must be IEvent or extend IEvent',
                             event_type)
-        reftype, token, wrapped_object = getWayToSubscribe(
+        reftype, token, wrapped_object, clean_object = getWayToSubscribe(
                 wrapped_self, reference)
+
         # If wrapped_object is None, the object can't be traversed to,
         # so raise an exception
         if wrapped_object is None:
             raise NotFoundError(reference)
 
+        clean_self = removeAllProxies(wrapped_self)
+
+        if clean_object is clean_self:
+           raise RuntimeError("Cannot subscribe to self")
+
         # Check that ISubscriber adapter exists for the wrapped object.
         # This will raise an error if there is no such adapter.
         getAdapter(wrapped_object, ISubscriber)
@@ -96,8 +102,6 @@
         else:
             ev_type = event_type
 
-        clean_self = removeAllProxies(wrapped_self)
-
         subscribers = clean_self._registry.get(ev_type)
         if subscribers is None:
             subscribers = []
@@ -463,11 +467,11 @@
     clean, wrapped, path, hubId, reftype = getWaysToSubscribe(
         context, reference, allways=False)
     if reftype is unicode or hubId is None:
-        return unicode, path, wrapped
+        return unicode, path, wrapped, clean
     if path is None and hubId is None:
         raise Exception('Can get neither path nor hubId for reference',
                         reference)
-    return int, hubId, wrapped
+    return int, hubId, wrapped, clean
 
 def getWaysToSubscribe(context, reference, allways=True):
     '''Get the various means of subscription available for the given
@@ -514,11 +518,8 @@
         else:
             cleanobj = removeAllProxies(wrappedobj)
             if allways:
-                try:
-                    hub = getService(context, HubIds)
-                except ComponentLookupError:
-                    pass
-                else:
+                hub = queryService(context, HubIds)
+                if hub is not None:
                     try:
                         hubId = hub.getHubId(path)
                     except NotFoundError:
@@ -528,11 +529,8 @@
         wrappedobj = reference
         cleanobj = clean_reference
         path = getPhysicalPathString(wrappedobj)
-        try:
-            hub = getService(context, HubIds)
-        except ComponentLookupError:
-            pass
-        else:
+        hub = queryService(context, HubIds)
+        if hub is not None:
             try:
                 hubId = hub.getHubId(path)
             except NotFoundError: