--- a/src/pyams_utils/request.py	Thu Mar 15 09:24:20 2018 +0100
+++ b/src/pyams_utils/request.py	Thu Mar 15 09:25:02 2018 +0100
@@ -31,6 +31,42 @@
 _marker = object()
 
 
+class RequestSelector(object):
+    """Interface based request selector
+
+    This selector can be used as a subscriber predicate to define
+    an interface that the event's 'request' attribute must support for the event to be applied::
+
+    .. code-block:: python
+
+        from pyams_utils.interfaces.site import ISiteRoot
+
+        @subscriber(IBeforeTraverseEvent, request_selector=IPyAMSLayer)
+        def before_traverse_event(event):
+            '''This is an event handler for an IPyAMSRequest modification event'''
+    """
+
+    def __init__(self, ifaces, config):
+        if not isinstance(ifaces, (list, tuple, set)):
+            ifaces = (ifaces,)
+        self.interfaces = ifaces
+
+    def text(self):
+        return 'request_selector = %s' % str(self.interfaces)
+
+    phash = text
+
+    def __call__(self, event):
+        for intf in self.interfaces:
+            try:
+                if intf.providedBy(event.request):
+                    return True
+            except (AttributeError, TypeError):
+                if isinstance(event.request, intf):
+                    return True
+        return False
+
+
 def request_property(key=None, prefix=None):
     """Define a method decorator used to store result into current request's annotations