--- a/src/server/server.py	Wed Mar 29 19:46:04 2017 +0200
+++ b/src/server/server.py	Wed Mar 29 19:46:27 2017 +0200
@@ -1777,6 +1777,28 @@
         # FIXME: check that no information is leaked (c.f. https://twistedmatrix.com/documents/current/web/howto/using-twistedweb.html#request-encoders)
         self.root.putChild(path, web_resource.EncodingResourceWrapper(resource, [server.GzipEncoderFactory()]))
 
+    ## Sessions ##
+
+    def purgeSession(self, request):
+        """helper method to purge a session during request handling"""
+        session = request.session
+        if session is not None:
+            log.debug(_(u"session purge"))
+            session.expire()
+            # FIXME: not clean but it seems that it's the best way to reset
+            #        session during request handling
+            request._secureSession = request._insecureSession = None
+
+    def getSessionData(self, request, *args):
+        """helper method to retrieve session data
+
+        @param request(server.Request): request linked to the session
+        @param *args(zope.interface.Interface): interface of the session to get
+        @return (iterator(data)): requested session data
+        """
+        session = request.getSession()
+        return (iface(session) for iface in args)
+
     ## TLS related methods ##
 
     def _TLSOptionsCheck(self):