From: Thierry Parmentelat <thierry.parmentelat@inria.fr>
Date: Tue, 3 Sep 2013 15:59:08 +0000 (+0200)
Subject: logout_on_manifold_exception : a decorator for dealing with manifold exceptions insid... 
X-Git-Tag: myslice-0.2-1~24^2~3
X-Git-Url: http://git.onelab.eu/?p=myslice.git;a=commitdiff_plain;h=f8ab9d13886a50daf7500e0b4d669e37f91ab4de

logout_on_manifold_exception : a decorator for dealing with manifold exceptions inside a view (when implemented as a function)
---

diff --git a/myslice/viewutils.py b/myslice/viewutils.py
index 7fbdc77f..3fa8ceba 100644
--- a/myslice/viewutils.py
+++ b/myslice/viewutils.py
@@ -30,3 +30,29 @@ def the_user (request):
     else: 
         return request.user.email
 
+
+# a decorator for view classes to catch manifold exceptions
+# by design views should not directly exercise a manifold query
+# given that these are asynchroneous, you would expect a view to just 
+# return a mundane skeleton
+# however of course this is not always true, and if only for metadata 
+# that for some reason we deal with some other way, it is often a good idea
+# for a view to monitor these exceptions - and to take this opportunity to 
+# logout people if it's a matter of expired session for example
+def logout_on_manifold_exception (view_as_a_function):
+    def wrapped (request, *args, **kwds):
+        try:
+            return view_as_a_function(request,*args, **kwds)
+        except ManifoldException, manifold_result:
+            # xxx we need a means to display this message to user...
+            from django.contrib.auth import logout
+            logout(request)
+            return HttpResponseRedirect ('/')
+        except Exception, e:
+            # xxx we need to sugarcoat this error message in some error template...
+            print "Unexpected exception",e
+            import traceback
+            traceback.print_exc()
+            return HttpResponseRedirect ('/')
+    return wrapped
+
diff --git a/portal/sliceview.py b/portal/sliceview.py
index 534ed78a..5bf37fb0 100644
--- a/portal/sliceview.py
+++ b/portal/sliceview.py
@@ -11,7 +11,7 @@ from manifold.manifoldresult         import ManifoldException
 from manifold.metadata               import MetaData as Metadata
 # need to remove this dep.
 from trash.trashutils                import quickfilter_criterias
-from myslice.viewutils               import topmenu_items, the_user
+from myslice.viewutils               import topmenu_items, the_user, logout_on_manifold_exception
 
 from plugins.raw.raw                 import Raw
 from plugins.stack.stack             import Stack
@@ -31,27 +31,9 @@ from plugins.messages.messages       import Messages
 tmp_default_slice='ple.upmc.myslicedemo'
 debug = True
 
+@logout_on_manifold_exception
 @login_required
 def slice_view (request, slicename=tmp_default_slice):
-    # xxx Thierry - ugly hack
-    # fetching metadata here might fail - e.g. with an expired session..
-    # let's catch this early on and log out our user if needed
-    # it should of course be handled in a more generic way
-    try:
-        return _slice_view(request,slicename)
-    except ManifoldException, manifold_result:
-        # xxx needs a means to display this message to user...
-        from django.contrib.auth import logout
-        logout(request)
-        return HttpResponseRedirect ('/')
-    except Exception, e:
-        # xxx we need to sugarcoat this error message in some error template...
-        print "Unexpected exception",e
-        import traceback
-        traceback.print_exc()
-        # return ...
-
-def _slice_view (request, slicename):
 
     page = Page(request)
     page.expose_js_metadata()