[Zope3-checkins] SVN: Zope3/trunk/src/zope/app/publisher/browser/menu. When a view cannot be found, it raises a `TraversalError`; since

[Stephan Richter]

Log message for revision 40164:
  When a view cannot be found, it raises a `TraversalError`; since 
  `MenuItem.available()` did not handle those errors, this error ended up 
  uncaught. If used in a traversal (which is usually the case), then error 
  was then masked as a traversal error of the menu itself, which was very 
  confusing. Now, `available()` catches `LookupError`s (a superclass of 
  `TraversalError`) and returns `False`. 
  
  So the result for the end user is: If someone created a menu item for a 
  non-existent view, it is always ignored, instead of breaking the menu code 
  in very unexpected ways.
  
  

Changed:
  U   Zope3/trunk/src/zope/app/publisher/browser/menu.py
  U   Zope3/trunk/src/zope/app/publisher/browser/menu.txt

-=-
Modified: Zope3/trunk/src/zope/app/publisher/browser/menu.py
===================================================================
--- Zope3/trunk/src/zope/app/publisher/browser/menu.py	2005-11-16 17:16:26 UTC (rev 40163)
+++ Zope3/trunk/src/zope/app/publisher/browser/menu.py	2005-11-16 17:55:09 UTC (rev 40164)
@@ -34,7 +34,6 @@
 from zope.app.publisher.interfaces.browser import IBrowserSubMenuItem
 from zope.app.publisher.interfaces.browser import IMenuItemType
 
-
 class BrowserMenu(object):
     """Browser Menu"""
     implements(IBrowserMenu)
@@ -114,7 +113,7 @@
             try:
                 view = traverser.traverseRelativeURL(
                     self.request, self.context, path)
-            except (Unauthorized, Forbidden):
+            except (Unauthorized, Forbidden, LookupError):
                 return False
             else:
                 # we're assuming that view pages are callable

Modified: Zope3/trunk/src/zope/app/publisher/browser/menu.txt
===================================================================
--- Zope3/trunk/src/zope/app/publisher/browser/menu.txt	2005-11-16 17:16:26 UTC (rev 40163)
+++ Zope3/trunk/src/zope/app/publisher/browser/menu.txt	2005-11-16 17:55:09 UTC (rev 40164)
@@ -51,18 +51,20 @@
 
   >>> class Content(object):
   ...     zope.interface.implements(IContent, IBrowserPublisher)
-  ... 
+  ...
   ...     def foo(self):
   ...         pass
-  ... 
+  ...
   ...     def browserDefault(self, r):
   ...         return self, ()
-  ... 
+  ...
   ...     def publishTraverse(self, request, name):
   ...         if name.startswith('fb'):
   ...             raise Forbidden, name
   ...         if name.startswith('ua'):
   ...             raise Unauthorized, name
+  ...         if name.startswith('le'):
+  ...             raise LookupError, name
   ...         return self.foo
 
 We also implemented the ``IBrowserPublisher`` interface, because we want to
@@ -134,7 +136,7 @@
 
 Now, we are not setting any user. This means that the menu item should be
 available.
-  
+
   >>> from zope.security.management import newInteraction, endInteraction
   >>> endInteraction()
   >>> newInteraction()
@@ -154,7 +156,7 @@
 
   >>> item.permission = None
 
-  All views starting with 'f' are forbidden, the ones with 'u' are
+  All views starting with 'fb' are forbidden, the ones with 'ua' are
   unauthorized and all others are allowed.
 
   >>> item.action = u'fb'
@@ -167,10 +169,20 @@
   >>> item.available()
   True
 
+Also, sometimes a menu item might be registered for a view that does not
+exist. In those cases the traversal mechanism raises a `TraversalError`, which
+is a special type of `LookupError`. All actions starting with `le` should
+raise this error:
+
+  >>> item.action = u'le'
+  >>> item.available()
+  False
+
 Now let's test filtering. If the filter is specified, it is assumed to be
 a TALES obejct.
 
   >>> from zope.app.pagetemplate.engine import Engine
+  >>> item.action = u'a'
   >>> item.filter = Engine.compile('not:context')
   >>> item.available()
   False