- Add a new event type: ``repoze.bfg.events.AfterTraversal``. Events

  of this type will be sent after traversal is completed, but before
  any view code is invoked.  Like ``repoze.bfg.events.NewRequest``,
  This event will have a single attribute: ``request`` representing
  the current request.  Unlike the request attribute of
  ``repoze.bfg.events.NewRequest`` however, during an AfterTraversal
  event, the request object will possess attributes set by the
  traverser, most notably ``context``, which will be the context used
  when a view is found and invoked.  The interface
  ``repoze.bfg.events.IAfterTraversal`` can be used to subscribe to
  the event.  For example::

    <subscriber for="repoze.bfg.interfaces.IAfterTraversal"
                handler="my.app.handle_after_traverse"/>

  Like any framework event, a subscriber function should expect one
  parameter: ``event``.

7 files changed, 95 insertions, 7 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index edd3170ff..b1d84c4d1 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -12,6 +12,27 @@ Documentation
 - "What's New in ``repoze.bfg`` 1.1" document added to narrative
   documentation.
 
+Features
+--------
+
+- Add a new event type: ``repoze.bfg.events.AfterTraversal``.  Events
+  of this type will be sent after traversal is completed, but before
+  any view code is invoked.  Like ``repoze.bfg.events.NewRequest``,
+  This event will have a single attribute: ``request`` representing
+  the current request.  Unlike the request attribute of
+  ``repoze.bfg.events.NewRequest`` however, during an AfterTraversal
+  event, the request object will possess attributes set by the
+  traverser, most notably ``context``, which will be the context used
+  when a view is found and invoked.  The interface
+  ``repoze.bfg.events.IAfterTraversal`` can be used to subscribe to
+  the event.  For example::
+
+    <subscriber for="repoze.bfg.interfaces.IAfterTraversal"
+                handler="my.app.handle_after_traverse"/>
+
+  Like any framework event, a subscriber function should expect one
+  parameter: ``event``.
+
 Dependencies
 ------------
 
diff --git a/docs/whatsnew-1.1.rst b/docs/whatsnew-1.1.rst
index e84d38a13..655e73882 100644
--- a/docs/whatsnew-1.1.rst
+++ b/docs/whatsnew-1.1.rst
@@ -595,6 +595,23 @@ Minor Miscellaneous Feature Additions
   registered forbidden view.  When the router catches a ``NotFound``,
   it returns the registered notfound view.
 
+- Add a new event type: ``repoze.bfg.events.AfterTraversal``.  Events
+  of this type will be sent after traversal is completed, but before
+  any view code is invoked.  Like ``repoze.bfg.events.NewRequest``,
+  This event will have a single attribute: ``request`` representing
+  the current request.  Unlike the request attribute of
+  ``repoze.bfg.events.NewRequest`` however, during an AfterTraversal
+  event, the request object will possess attributes set by the
+  traverser, most notably ``context``, which will be the context used
+  when a view is found and invoked.  The interface
+  ``repoze.bfg.events.IAfterTraversal`` can be used to subscribe to
+  the event.  For example::
+
+    <subscriber for="repoze.bfg.interfaces.IAfterTraversal"
+                handler="my.app.handle_after_traverse"/>
+
+  Like any framework event, a subscriber function should expect one
+  parameter: ``event``.
 
 Backwards Incompatibilities
 ---------------------------
diff --git a/repoze/bfg/events.py b/repoze/bfg/events.py
index 54f60c294..14e47ca3f 100644
--- a/repoze/bfg/events.py
+++ b/repoze/bfg/events.py
@@ -1,5 +1,6 @@
 from zope.interface import implements
 
+from repoze.bfg.interfaces import IAfterTraversal
 from repoze.bfg.interfaces import INewRequest
 from repoze.bfg.interfaces import INewResponse
 from repoze.bfg.interfaces import IWSGIApplicationCreatedEvent
@@ -23,6 +24,20 @@ class NewResponse(object):
     def __init__(self, response):
         self.response = response
 
+class AfterTraversal(object):
+    implements(IAfterTraversal)
+    """ An instance of this class is emitted as an event after the
+    repoze.bfg router performs traversal (but before any view code is
+    executed).  The instance has an attribute, ``request``, which is
+    the request object returned by the view.  Notably, the request
+    object will have an attribute named ``context``, which is the
+    context that will be provided to the view which will eventually be
+    called, as well as other attributes defined by the traverser.
+    This class implements the
+    ``repoze.bfg.interfaces.IAfterTraversal`` interface."""
+    def __init__(self, request):
+        self.request = request
+    
 class WSGIApplicationCreatedEvent(object):    
     """ An instance of this class is emitted as an event whenever a
     ``repoze.bfg`` application starts.  The instance has an attribute,
@@ -32,7 +47,5 @@ class WSGIApplicationCreatedEvent(object):
     implements(IWSGIApplicationCreatedEvent)
     def __init__(self, app):
         self.app = app
+        self.object = app
 
-    @property
-    def object(self):
-        return self.app
diff --git a/repoze/bfg/interfaces.py b/repoze/bfg/interfaces.py
index 53b01bfd6..582e8984d 100644
--- a/repoze/bfg/interfaces.py
+++ b/repoze/bfg/interfaces.py
@@ -120,6 +120,11 @@ class IRouter(Interface):
     registry = Attribute(
         """Component architecture registry local to this application.""")
     
+class IAfterTraversal(Interface):
+    """ An event type that is emitted after repoze.bfg completes
+    traversal but before it calls any view code."""
+    request = Attribute('The request object')
+
 class INewRequest(Interface):
     """ An event type that is emitted whenever repoze.bfg begins to
     process a new request """
diff --git a/repoze/bfg/router.py b/repoze/bfg/router.py
index c3580a8da..ca0f8e449 100644
--- a/repoze/bfg/router.py
+++ b/repoze/bfg/router.py
@@ -14,6 +14,7 @@ from repoze.bfg.interfaces import IView
 
 from repoze.bfg.configuration import make_registry
 from repoze.bfg.configuration import DefaultRootFactory
+from repoze.bfg.events import AfterTraversal
 from repoze.bfg.events import NewRequest
 from repoze.bfg.events import NewResponse
 from repoze.bfg.events import WSGIApplicationCreatedEvent
@@ -54,6 +55,7 @@ class Router(object):
         iterable.
         """
         registry = self.registry
+        has_listeners = registry.has_listeners
         logger = self.logger
         manager = self.threadlocal_manager
         threadlocals = {'registry':registry, 'request':None}
@@ -65,7 +67,7 @@ class Router(object):
             threadlocals['request'] = request
             attrs = request.__dict__
             attrs['registry'] = registry
-            registry.has_listeners and registry.notify(NewRequest(request))
+            has_listeners and registry.notify(NewRequest(request))
 
             # view lookup
             root = self.root_factory(request)
@@ -79,6 +81,7 @@ class Router(object):
                 tdict['traversed'], tdict['virtual_root'],
                 tdict['virtual_root_path'])
             attrs.update(tdict)
+            has_listeners and registry.notify(AfterTraversal(request))
             provides = map(providedBy, (context, request))
             view_callable = registry.adapters.lookup(
                 provides, IView, name=view_name, default=None)
@@ -111,7 +114,7 @@ class Router(object):
                     response = self.notfound_view(context, request)
 
             # response handling
-            registry.has_listeners and registry.notify(NewResponse(response))
+            has_listeners and registry.notify(NewResponse(response))
 
             try:
                 headers = response.headerlist
diff --git a/repoze/bfg/tests/test_events.py b/repoze/bfg/tests/test_events.py
index d7ab772f5..f1cbfff5b 100644
--- a/repoze/bfg/tests/test_events.py
+++ b/repoze/bfg/tests/test_events.py
@@ -66,6 +66,31 @@ class WSGIAppEventTests(unittest.TestCase):
         from zope.interface.verify import verifyClass
         verifyClass(IWSGIApplicationCreatedEvent, WSGIApplicationCreatedEvent)
 
+class AfterTraversalEventTests(unittest.TestCase):
+    def _getTargetClass(self):
+        from repoze.bfg.events import AfterTraversal
+        return AfterTraversal
+
+    def _makeOne(self, request):
+        return self._getTargetClass()(request)
+
+    def test_class_implements(self):
+        from repoze.bfg.interfaces import IAfterTraversal
+        from zope.interface.verify import verifyClass
+        klass = self._getTargetClass()
+        verifyClass(IAfterTraversal, klass)
+        
+    def test_instance_implements(self):
+        from repoze.bfg.interfaces import IAfterTraversal
+        from zope.interface.verify import verifyObject
+        request = DummyRequest()
+        inst = self._makeOne(request)
+        verifyObject(IAfterTraversal, inst)
+
+    def test_ctor(self):
+        request = DummyRequest()
+        inst = self._makeOne(request)
+        self.assertEqual(inst.request, request)
 
 class DummyRequest:
     pass
diff --git a/repoze/bfg/tests/test_router.py b/repoze/bfg/tests/test_router.py
index 1e5382dde..d5bc8cd66 100644
--- a/repoze/bfg/tests/test_router.py
+++ b/repoze/bfg/tests/test_router.py
@@ -382,6 +382,9 @@ class TestRouter(unittest.TestCase):
         self.assertEqual(start_response.headers, [('a', 1), ('b', 2)])
 
     def test_call_eventsends(self):
+        from repoze.bfg.interfaces import INewRequest
+        from repoze.bfg.interfaces import INewResponse
+        from repoze.bfg.interfaces import IAfterTraversal
         context = DummyContext()
         self._registerTraverserFactory(context)
         response = DummyResponse()
@@ -389,15 +392,16 @@ class TestRouter(unittest.TestCase):
         view = DummyView(response)
         environ = self._makeEnviron()
         self._registerView(view, '', None, None)
-        from repoze.bfg.interfaces import INewRequest
-        from repoze.bfg.interfaces import INewResponse
         request_events = self._registerEventListener(INewRequest)
+        aftertraversal_events = self._registerEventListener(IAfterTraversal)
         response_events = self._registerEventListener(INewResponse)
         router = self._makeOne()
         start_response = DummyStartResponse()
         result = router(environ, start_response)
         self.assertEqual(len(request_events), 1)
         self.assertEqual(request_events[0].request.environ, environ)
+        self.assertEqual(len(aftertraversal_events), 1)
+        self.assertEqual(aftertraversal_events[0].request.environ, environ)
         self.assertEqual(len(response_events), 1)
         self.assertEqual(response_events[0].response, response)