This exception can be imported using:
from skipole import ValidateError
It has arguments:
ValidateError(message = '', section='', widget='', status='400 Bad Request')
Within the Admin session pages the section on 'labels' lists a number of special pre-defined pages. One of these has label 'validate_error'. Raising a ValidateError exception will return the page with this label.
This gives the developer the option of using the pre-defined page, or by setting the label to point to another page, a different validate error page could be defined.
Normally leave section and widget empty to allow the message to be displayed in the page default error widget.