Fix first() and last() to work with Zope security, document them.

lib/python/Products/PageTemplates/Expressions.py

@@ -17,7 +17,7 @@ Page Template-specific implementation of TALES, with handlers
 for Python expressions, string literals, and paths.
 """
 
-__version__='$Revision: 1.30 $'[11:-2]
+__version__='$Revision: 1.31 $'[11:-2]
 
 import re, sys
 from TALES import Engine, CompilerError, _valid_name, NAME_RE, \
@@ -272,7 +272,8 @@ class DeferExpr:
 
 
 def restrictedTraverse(self, path, securityManager,
-                       get=getattr, has=hasattr, N=None, M=[]):
+                       get=getattr, has=hasattr, N=None, M=[],
+                       TupleType=type(()) ):
 
     REQUEST = {'path': path}
     REQUEST['TraversalRequestNameStack'] = path = path[:] # Copy!
@@ -290,6 +291,10 @@ def restrictedTraverse(self, path, securityManager,
         __traceback_info__ = REQUEST
         name = path.pop()
 
+        if isinstance(name, TupleType):
+            object = apply(object, name)
+            continue
+
         if name[0] == '_':
             # Never allowed in a URL.
             raise AttributeError, name

lib/python/Products/PageTemplates/PathIterator.py

@@ -17,21 +17,21 @@ A TALES Iterator with the ability to use first() and last() on
 subpaths of elements.
 """
 
-__version__='$Revision: 1.1 $'[11:-2]
+__version__='$Revision: 1.2 $'[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)
-            del path[:]
             names.reverse()
-            return getattr(self, name)(names)
+            path[:] = [tuple(names)]
         return getattr(self, name)
-            
+
     def same_part(self, name, ob1, ob2):
         if name is None:
             return ob1 == ob2

lib/python/Products/PageTemplates/help/tal-repeat.stx

@@ -42,6 +42,10 @@ repeat: Repeat an element
 
       o *end* - true for the ending, or final, repetition.
 
+      o *first* - true for the first item in a group - see note below
+
+      o *last* - true for the last item in a group - see note below
+
       o *length* - length of the sequence, which will be the total number
         of repetitions.
 
@@ -65,6 +69,15 @@ repeat: Repeat an element
     attribute access to get the information, for example,
     'python:repeat['item'].start'.
 
+    Note that 'first' and 'last' are intended for use with sorted
+    sequences.  They try to divide the sequence into group of items
+    with the same value.  If you provide a path, then the value
+    obtained by following that path from a sequence item is used for
+    grouping, otherwise the value of the item is used.  You can
+    provide the path by passing it as a parameter, as in
+    "python:repeat['item'].first('color')", or by appending it to the
+    path from the repeat variable, as in "repeat/item/first/color".
+
   Examples
 
     Iterating over a sequence of strings::    
@@ -96,3 +109,12 @@ repeat: Repeat an element
           </td>
         </tr>
       </table>
+
+    Objects (already sorted by meta-type) in groups by meta-type::
+
+      <table border="1">
+        <tr tal:repeat="object objects">
+          <td><span tal:condition="repeat/object/first/meta_type"
+                    tal:replace="object/meta_type">Meta Type</span></td>
+        </tr>
+      </table>