* @return a non-null (though possibly empty) list of field names
*/
protected Collection<String> getFieldsPresentInfo(ActionBean bean) {
ActionBeanContext ctx = bean.getContext();
String fieldsPresent = ctx.getRequest().getParameter(StripesConstants.URL_KEY_FIELDS_PRESENT);
Wizard wizard = bean.getClass().getAnnotation(Wizard.class);
boolean isWizard = wizard != null;
if (fieldsPresent == null || "".equals(fieldsPresent)) {
if (isWizard && !CollectionUtil.contains(wizard.startEvents(), ctx.getEventName())) {
throw new StripesRuntimeException(
"Submission of a wizard form in Stripes absolutely requires that "
+ "the hidden field Stripes writes containing the names of the fields "
+ "present on the form is present and encrypted (as Stripes write it). "
+ "This is necessary to prevent a user from spoofing the system and "