'Create a job.*dir -> job._*dir.path property accessor.
:param attribute: A string with the name of the attribute this is
exposed as. \'_\'+attribute must then be attribute
that holds either None or a job_directory-like object
:returns: A read-only property object that exposes a job_directory path'

@staticmethod
def property_factory(attribute):

    @property
    def dir_property(self):
        underlying_attribute = getattr(self, ('_' + attribute))
        if (underlying_attribute is None):
            return None
        else:
            return underlying_attribute.path
    return dir_property
