- Make the (internal) thread local registry manager maintain a stack

  of registries in order to make it possible to call one BFG
  application from inside another.

5 files changed, 111 insertions, 75 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index 46a8cf542..5bda29b6d 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -36,6 +36,10 @@ Features
 - Projects generated by the paster templates now use the
   ``DummyTemplateRenderer.assert_`` method in their view tests.
 
+- Make the (internal) thread local registry manager maintain a stack
+  of registries in order to make it possible to call one BFG
+  application from inside another.
+
 Bug Fixes
 ---------
 
diff --git a/repoze/bfg/registry.py b/repoze/bfg/registry.py
index f2f47a889..179fbd3dd 100644
--- a/repoze/bfg/registry.py
+++ b/repoze/bfg/registry.py
@@ -25,15 +25,26 @@ deprecated(
     )
 
 class ThreadLocalRegistryManager(threading.local):
-    registry = getGlobalSiteManager()
-    def set(self, registry):
-        self.registry = registry
+    def __init__(self):
+        self.stack = []
+        
+    def push(self, registry):
+        self.stack.append(registry)
+
+    set = push # backwards compatibility
+
+    def pop(self):
+        if self.stack:
+            return self.stack.pop()
 
     def get(self):
-        return self.registry
+        try:
+            return self.stack[-1]
+        except IndexError:
+            return getGlobalSiteManager()
 
     def clear(self):
-        self.registry = getGlobalSiteManager()
+        self.stack[:] = []
 
 registry_manager = ThreadLocalRegistryManager()
 
@@ -62,7 +73,7 @@ def makeRegistry(filename, package, lock=threading.Lock()):
     lock.acquire()
     try:
         registry = Components(package.__name__)
-        registry_manager.set(registry)
+        registry_manager.push(registry)
         original_getSiteManager.sethook(getSiteManager)
         zope.component.getGlobalSiteManager = registry_manager.get
         zcml_configure(filename, package=package)
@@ -70,7 +81,7 @@ def makeRegistry(filename, package, lock=threading.Lock()):
     finally:
         zope.component.getGlobalSiteManager = getGlobalSiteManager
         lock.release()
-        registry_manager.clear()
+        registry_manager.pop()
 
 def getSiteManager(context=None):
     if context is None:
diff --git a/repoze/bfg/router.py b/repoze/bfg/router.py
index 622a8870b..ffbd853dc 100644
--- a/repoze/bfg/router.py
+++ b/repoze/bfg/router.py
@@ -48,62 +48,69 @@ class Router(object):
         'view' code based on registrations within the application
         registry; call ``start_response`` and return an iterable.
         """
-        registry_manager.set(self.registry)
-        request = Request(environ)
-        directlyProvides(request, IRequest)
-        dispatch(NewRequest(request))
-
-        root_factory = getUtility(IRootFactory)
-        root = root_factory(environ)
-        traverser = getAdapter(root, ITraverserFactory)
-        context, view_name, subpath = traverser(environ)
-
-        request.root = root
-        request.context = context
-        request.view_name = view_name
-        request.subpath = subpath
-
-        permitted = view_execution_permitted(context, request, view_name)
-
-        settings = queryUtility(ISettings)
-        debug_authorization = settings and settings.debug_authorization
-
-        if debug_authorization:
-            logger = queryUtility(ILogger, 'repoze.bfg.debug')
-            logger and logger.debug(
-                'debug_authorization of url %s (view name %r against context '
-                '%r): %s' % (request.url, view_name, context, permitted.msg)
-                )
-        if not permitted:
+        registry_manager.push(self.registry)
+
+        try:
+            request = Request(environ)
+            directlyProvides(request, IRequest)
+            dispatch(NewRequest(request))
+
+            root_factory = getUtility(IRootFactory)
+            root = root_factory(environ)
+            traverser = getAdapter(root, ITraverserFactory)
+            context, view_name, subpath = traverser(environ)
+
+            request.root = root
+            request.context = context
+            request.view_name = view_name
+            request.subpath = subpath
+
+            permitted = view_execution_permitted(context, request, view_name)
+
+            settings = queryUtility(ISettings)
+            debug_authorization = settings and settings.debug_authorization
+
             if debug_authorization:
-                msg = permitted.msg
-            else:
-                msg = 'Unauthorized: failed security policy check'
-            app = HTTPUnauthorized(escape(msg))
-            return app(environ, start_response)
-            
-        response = render_view_to_response(context, request, view_name,
-                                           secure=False)
-
-        if response is None:
-            debug_notfound = settings and settings.debug_notfound
-            if debug_notfound:
                 logger = queryUtility(ILogger, 'repoze.bfg.debug')
-                msg = (
-                    'debug_notfound of url %s; path_info: %r, context: %r, '
-                    'view_name: %r, subpath: %r' % (
-                    request.url, request.path_info, context, view_name, subpath)
+                logger and logger.debug(
+                    'debug_authorization of url %s (view name %r against '
+                    'context %r): %s' % (
+                    request.url, view_name, context, permitted.msg)
                     )
-                logger and logger.debug(msg)
-            else:
-                msg = request.url
-            app = HTTPNotFound(escape(msg))
-            return app(environ, start_response)
-
-        dispatch(NewResponse(response))
-
-        start_response(response.status, response.headerlist)
-        return response.app_iter
+            if not permitted:
+                if debug_authorization:
+                    msg = permitted.msg
+                else:
+                    msg = 'Unauthorized: failed security policy check'
+                app = HTTPUnauthorized(escape(msg))
+                return app(environ, start_response)
+
+            response = render_view_to_response(context, request, view_name,
+                                               secure=False)
+
+            if response is None:
+                debug_notfound = settings and settings.debug_notfound
+                if debug_notfound:
+                    logger = queryUtility(ILogger, 'repoze.bfg.debug')
+                    msg = (
+                        'debug_notfound of url %s; path_info: %r, context: %r, '
+                        'view_name: %r, subpath: %r' % (
+                        request.url, request.path_info, context, view_name,
+                        subpath)
+                        )
+                    logger and logger.debug(msg)
+                else:
+                    msg = request.url
+                app = HTTPNotFound(escape(msg))
+                return app(environ, start_response)
+
+            dispatch(NewResponse(response))
+
+            start_response(response.status, response.headerlist)
+            return response.app_iter
+
+        finally:
+            registry_manager.pop()
 
 def make_app(root_factory, package=None, filename='configure.zcml',
              options=None):
@@ -130,10 +137,10 @@ def make_app(root_factory, package=None, filename='configure.zcml',
     app = Router(registry)
 
     try:
-        registry_manager.set(registry)
+        registry_manager.push(registry)
         dispatch(WSGIApplicationCreatedEvent(app))
     finally:
-        registry_manager.clear()
+        registry_manager.pop()
 
     return app
 
diff --git a/repoze/bfg/tests/test_registry.py b/repoze/bfg/tests/test_registry.py
index 0d051c131..51883b196 100644
--- a/repoze/bfg/tests/test_registry.py
+++ b/repoze/bfg/tests/test_registry.py
@@ -49,16 +49,28 @@ class TestThreadLocalRegistryManager(unittest.TestCase, PlacelessSetup):
     def test_init(self):
         local = self._makeOne()
         from zope.component import getGlobalSiteManager
-        self.assertEqual(local.registry, getGlobalSiteManager())
+        self.assertEqual(local.stack, [])
+        self.assertEqual(local.get(), getGlobalSiteManager())
+
+    def test_push_and_pop(self):
+        local = self._makeOne()
+        from zope.component import getGlobalSiteManager
+        local.push(True)
+        self.assertEqual(local.get(), True)
+        self.assertEqual(local.pop(), True)
+        self.assertEqual(local.pop(), None)
+        self.assertEqual(local.get(), getGlobalSiteManager())
 
     def test_set_get_and_clear(self):
         local = self._makeOne()
         from zope.component import getGlobalSiteManager
         local.set(None)
-        self.failIfEqual(local.registry, getGlobalSiteManager())
+        self.assertEqual(local.stack, [None])
         self.assertEqual(local.get(), None)
         local.clear()
-        self.assertEqual(local.registry, getGlobalSiteManager())
+        self.assertEqual(local.get(), getGlobalSiteManager())
+        local.clear()
+        self.assertEqual(local.get(), getGlobalSiteManager())
 
 class GetSiteManagerTests(unittest.TestCase):
     def _getFUT(self):
@@ -76,16 +88,15 @@ class GetSiteManagerTests(unittest.TestCase):
         self.assertRaises(ComponentLookupError, gsm, object)
         
 class DummyRegistrationManager:
-    registry = None
-    def set(self, registry):
+    def push(self, registry):
         self.registry = registry
 
+    def pop(self):
+        self.popped = True
+
     def get(self):
         return self.registry
 
-    def clear(self):
-        self.cleared = True
-
 class DummyLock:
     def acquire(self):
         self.acquired = True
diff --git a/repoze/bfg/tests/test_router.py b/repoze/bfg/tests/test_router.py
index 3f52bd9cd..35ab21f9c 100644
--- a/repoze/bfg/tests/test_router.py
+++ b/repoze/bfg/tests/test_router.py
@@ -483,7 +483,8 @@ class MakeAppTests(unittest.TestCase, PlacelessSetup):
                   'debug_authorization':True}
         import repoze.bfg.router
         old_registry_manager = repoze.bfg.router.registry_manager
-        repoze.bfg.router.registry_manager = DummyRegistryManager()
+        dummy_registry_manager = DummyRegistryManager()
+        repoze.bfg.router.registry_manager = dummy_registry_manager
         try:
             from repoze.bfg.tests import fixtureapp
             rootpolicy = make_rootfactory(None)
@@ -498,15 +499,17 @@ class MakeAppTests(unittest.TestCase, PlacelessSetup):
             self.assertEqual(settings.reload_templates, True)
             self.assertEqual(settings.debug_authorization, True)
             self.assertEqual(rootfactory, rootpolicy)
+            self.assertEqual(dummy_registry_manager.pushed, True)
+            self.assertEqual(dummy_registry_manager.popped, True)
         finally:
             repoze.bfg.router.registry_manager = old_registry_manager
 
 class DummyRegistryManager:
-    def set(self, registry):
-        pass
+    def push(self, registry):
+        self.pushed = True
 
-    def clear(self):
-        pass
+    def pop(self):
+        self.popped = True
 
 class DummyContext:
     pass