--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PageTemplates/PathIterator.py	Fri Aug 30 08:27:34 2002 +0000
@@ -0,0 +1,48 @@
+##############################################################################
+#
+# Copyright (c) 2001 Zope Corporation and Contributors. All Rights Reserved.
+# 
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.0 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE
+# 
+##############################################################################
+
+"""Path Iterator
+
+A TALES Iterator with the ability to use first() and last() on
+subpaths of elements.
+"""
+
+__version__='$Revision: 1.1 $'[11:-2]
+
+import TALES
+from Expressions import restrictedTraverse, Undefs, getSecurityManager
+from string import split
+
+class Iterator(TALES.Iterator):
+    def __bobo_traverse__(self, REQUEST, name):
+        if name in ('first', 'last'):
+            path = REQUEST['TraversalRequestNameStack']
+            names = list(path)
+            names.reverse()
+            path[:] = [tuple(names)]
+        return getattr(self, name)
+
+    def same_part(self, name, ob1, ob2):
+        if name is None:
+            return ob1 == ob2
+        if isinstance(name, type('')):
+            name = split(name, '/')
+        name = filter(None, name)
+        securityManager = getSecurityManager()
+        try:
+            ob1 = restrictedTraverse(ob1, name, securityManager)
+            ob2 = restrictedTraverse(ob2, name, securityManager)
+        except Undefs:
+            return 0
+        return ob1 == ob2
+