There was a case to catch the situation where there were no ontologies but no
method to handle that case.  I put the logic in the ontology selection form to
catch where there were no ontos to select from and report this.

In a new SGDI instance with no data, create a new workspace and then click on
the 'Select Samples Via Ontology' link.  I get a Site Error saying:

ite Error

An error was encountered while publishing this resource.

NameError

Sorry, a site error occurred.
Traceback (innermost last):

Module ZPublisher.Publish, line 188, in publish_module_standard
Module ZPublisher.Publish, line 145, in publish
Module Zope2.App.startup, line 222, in zpublisher_exception_hook
Module ZPublisher.Publish, line 114, in publish
Module ZPublisher.mapply, line 88, in mapply
Module ZPublisher.Publish, line 40, in call_object
Module Products.SGDI.SGDI, line 1150, in dispatchWorkspaceActivity
Module Products.SGDI.SGDI, line 2042, in selectOnto
NameError: global name 'foo' is not defined (Also, the following error occurred
while attempting to render the standard error message, please see the event log
for full details: You are not allowed to access 'title_or_id' in this context)