[z3-five] Templates in views and path expressions

[Martin Aspeli]

Hi guys,

This is driving me up the wall.

I have a content class:

class Project(Container):
     implements(IProject)
     portal_type = "Project"

     title = u""
     description = u""
     managers = []
     members = []
     workflow_policy = None
     addable_types = []

Protected with:

     <five:registerClass
         class=".content.Project"
         meta_type="b-org Project"
         permission="borg.project.AddProject"
         addview="borg.project.Project"
         icon="borg_project_icon.png"
         />

     <utility
         component=".content.projectFactory"
         name="borg.project.Project"
         />

     <class class=".content.Project">
         <require
             permission="zope2.View"
             interface=".interfaces.IProject"
             />
         <require
             permission="cmf.ModifyPortalContent"
             set_schema=".interfaces.IProject"
             />
     </class>

Then, I have a view:


And a template:

     <h1 tal:content="context/title" />

When I try to access this, I get:

Traceback (innermost last):
   Module ZPublisher.Publish, line 119, in publish
   Module ZPublisher.mapply, line 88, in mapply
   Module Products.PDBDebugMode.pdbzope.runcall, line 60, in pdb_runcall
   Module ZPublisher.Publish, line 42, in call_object
   Module Products.Five.browser.metaconfigure, line 416, in __call__
   Module Shared.DC.Scripts.Bindings, line 313, in __call__
   Module Shared.DC.Scripts.Bindings, line 350, in _bindAndExec
   Module Products.PageTemplates.PageTemplateFile, line 129, in _exec
   Module Products.PageTemplates.PageTemplate, line 89, in pt_render
   Module zope.pagetemplate.pagetemplate, line 117, in pt_render
   Module zope.tal.talinterpreter, line 271, in __call__
   ...
   Module Products.PageTemplates.Expressions, line 199, in evaluateText
   Module zope.tales.tales, line 696, in evaluate
    - URL: index
    - Line 13, Column 4
    - Expression: <PathExpr standard:'context/title'>
    - Names:
       {'container': <Project at /test/workspace-one>,
        'context': <Project at /test/workspace-one>,
        'default': <object object at 0x53528>,
        'here': <Project at /test/workspace-one>,
        'loop': {},
        'nothing': None,
        'options': {'args': (<Products.Five.metaclass.SimpleViewClass 
from 
/Users/optilude/Development/Plone/Code/Products/borg/ng/borg.project/borg/project/browser/project.pt 
object at 0x6835410>,)},
        'repeat': <Products.PageTemplates.Expressions.SafeMapping object 
at 0x76c8d50>,
        'request': <HTTPRequest, 
URL=http://localhost:8080/test/workspace-one/@@view>,
        'root': <Application at >,
        'template': <ImplicitAcquirerWrapper object at 0x76bbe10>,
        'traverse_subpath': [],
        'user': <PropertiedUser 'admin'>,
        'view': <Products.Five.metaclass.SimpleViewClass from 
/Users/optilude/Development/Plone/Code/Products/borg/ng/borg.project/borg/project/browser/project.pt 
object at 0x6835410>,
        'views': <zope.app.pagetemplate.viewpagetemplatefile.ViewMapper 
object at 0x68354b0>}
   Module zope.tales.expressions, line 217, in __call__
   Module Products.PageTemplates.Expressions, line 131, in _eval
   Module zope.tales.expressions, line 124, in _eval
   Module Products.PageTemplates.Expressions, line 80, in 
boboAwareZopeTraverse
   Module OFS.Traversable, line 301, in restrictedTraverse
   Module OFS.Traversable, line 236, in unrestrictedTraverse
    - __traceback_info__: ([], 'title')
   Module AccessControl.ImplPython, line 563, in validate
   Module AccessControl.ImplPython, line 454, in validate
   Module AccessControl.ImplPython, line 808, in raiseVerbose
Unauthorized: Your user account is defined outside the context of the 
object being accessed.  Access to 'title' of (Project at 
/test/workspace-one) denied. Your user account, admin, exists at 
/acl_users. Access requires one of the following roles: ['Contributor', 
'Editor', 'Manager', 'Owner', 'Reader'].

I think this is because it's trying to security check 'title'. In 
ImplPython.py, with verbose security on, this is the one that's failing:

def verifyAcquisitionContext(user, object, object_roles=None):
     """Mimics the relevant section of User.allowed().

     Returns true if the object is in the context of the user's user folder.
     """
     ufolder = aq_parent(user)
     ucontext = aq_parent(ufolder)
     if ucontext is not None:
         if object is None:
             # This is a strange rule, though
             # it doesn't cause any security holes. SDH
             return 1
         if not hasattr(object, 'aq_inContextOf'):
             if hasattr(object, 'im_self'):
                 # This is a method.  Grab its self.
                 object=object.im_self
             if not hasattr(object, 'aq_inContextOf'):
                 # object is not wrapped, therefore we
                 # can't determine context.
                 # Fail the access attempt.  Otherwise
                 # this would be a security hole.
------->       return None
         if not object.aq_inContextOf(ucontext, 1):
             if 'Shared' in object_roles:
                 # Old role setting. Waaa
                 object_roles=user._shared_roles(object)
                 if 'Anonymous' in object_roles:
                     return 1
             return None
     # Note that if the user were not wrapped, it would
     # not be possible to determine the user's context
     # and this method would return 1.
     # However, as long as user folders always return
     # wrapped user objects, this is safe.
     return 1

With a breakpoint there, "object" is the string u"Some title", i.e. the 
value of the title attribute.

I can make this work by doing this:

     <h1 tal:content="python:context.title" />

Or, I can make it work by leaving the context/title syntax in the 
template, but commenting out the <class> <require /> ... bit.

So, first of all, it seems that:

  - ViewPageTemplateFile's in a browser view are doing restricted, 
rather than unrestricted traversals

  - The <require /> directive doesn't seem to work properly on simple 
properties

Are these bugs? Are my expectations unreasonable? What are the 
consequences of not having a <class> directive setting permissions on 
the content type?

Cheers,
Martin