External Source permissions issue

Hi All,

I have a code source in my silva root wich can be used to include a silva 
document within another doc.  One of our authors (who only has SMI access to 
a directory two levels inside the root) wanted to use this cs but was 
recieving an 'Unauthorized' error (traceback below)

I've tracked this down to the class-level permissions on 
ExternalSource.form().  It's set to SilvaPermissions.ReadSilvaContent.  
Obviously this author does not have a 'ReadSilvaContent' role at the silva 
root, so they are unable to use this code source.

Would it be possible to have a 'form_for_document' function which checks the 
permissions on the document and has public access?

For now, I've set the perms to SilvaPermissions.ViewAuthenticated, which 
should work.

Cheers,
Andy

Traceback (innermost last):

    * Module ZPublisher.Publish, line 101, in publish
    * Module ZPublisher.mapply, line 88, in mapply
    * Module ZPublisher.Publish, line 39, in call_object
    * Module Products.FileSystemSite.FSPythonScript, line 104, in __call__
    * Module Shared.DC.Scripts.Bindings, line 306, in __call__
    * Module Shared.DC.Scripts.Bindings, line 343, in _bindAndExec
    * Module Products.FileSystemSite.FSPythonScript, line 160, in _exec
    * Module None, line 4, in save
      <FSPythonScript at /silva/service_widgets/save used 
for /silva/service_widgets/element/doc_elements/source/mode_edit>
      Line 4
    * Module Products.FileSystemSite.FSPythonScript, line 104, in __call__
    * Module Shared.DC.Scripts.Bindings, line 306, in __call__
    * Module Shared.DC.Scripts.Bindings, line 343, in _bindAndExec
    * Module Products.FileSystemSite.FSPythonScript, line 160, in _exec
    * Module None, line 51, in save_helper
      <FSPythonScript 
at /silva/service_widgets/element/doc_elements/source/mode_edit/save_helper>
      Line 51