[Zope-Checkins] CVS: Zope/lib/python/Products/PageTemplates - Expressions.py:1.32.2.3

[Shane Hathaway]

Update of /cvs-repository/Zope/lib/python/Products/PageTemplates
In directory cvs.zope.org:/tmp/cvs-serv13864

Modified Files:
      Tag: shane-better-tracebacks-branch
	Expressions.py 
Log Message:
Catch only specific TypeErrors.  Added XXX comments--I hope Python 2.2 can
rescue us from this messy exception handling.  There's no way to know
whether an object supports the item interface without calling it.


=== Zope/lib/python/Products/PageTemplates/Expressions.py 1.32.2.2 => 1.32.2.3 ===
                 # Try an item.
                 try:
+                    # XXX maybe in Python 2.2 we can just check whether
+                    # the object has the attribute "__getitem__"
+                    # instead of blindly catching exceptions.
                     o = object[name]
                 except AttributeError, exc:
                     if str(exc).find('__getitem__') >= 0:
                         # The object does not support the item interface.
                         # Try to re-raise the original attribute error.
+                        # XXX I think this only happens with
+                        # ExtensionClass instances.
                         get(object, name)
                     raise
-                except TypeError:
-                    # The object does not support the item interface.
-                    # Try to re-raise the original attribute error.
-                    get(object, name)
-                    # Should not reach here, but just in case...
+                except TypeError, exc:
+                    if str(exc).find('unsubscriptable') >= 0:
+                        # The object does not support the item interface.
+                        # Try to re-raise the original attribute error.
+                        # XXX This is sooooo ugly.
+                        get(object, name)
                     raise
                 else:
                     # Check access to the item.