* @param context required listing context
* @param request the listing request
* @return the resultant listing payload
*/
public <S extends IMarshalable, R extends IMarshalable> ListingPayload<R> process(final String sessionId, final ListingContext context, final ListingRequest<S> request) {
final Status status = new Status();
if(request == null) {
status.addMsg("No listing request specified.", MsgLevel.ERROR, MsgAttr.STATUS.flag);
}
final String listingId = request == null ? null : request.getListingId();
if(listingId == null) {
status.addMsg("No listing id specified.", MsgLevel.ERROR, MsgAttr.STATUS.flag);
}
final ListingOp listingOp = request == null ? null : request.getListingOp();
if(listingOp == null) {
status.addMsg("No listing op specified.", MsgLevel.ERROR, MsgAttr.STATUS.flag);
}
ListingHandler<R> handler = null;
ListingStatus listingStatus = null;
if(!status.hasErrors() && request != null) {
if(sessionId == null) {
status.addMsg("No session id specified.", MsgLevel.ERROR, MsgAttr.STATUS.flag);
}
else {
final ListingCache lcache = context.getListingCache();
assert lcache != null : "Null ListingCache";
Integer offset = request.getOffset();
Sorting sorting = request.getSorting();
// get listing state (if cached)
final ListingState state = lcache.getState(sessionId, listingId);
if(state != null) {
log.debug("Found cached state for listing '{}': {}", listingId, state.toString());
if(offset == null) {
offset = state.getOffset();
assert offset != null;
log.debug("Setting offset ({}) from cache for listing: {}", offset, listingId);
}
if(sorting == null) {
sorting = state.getSorting();
assert sorting != null;
log.debug("Setting sorting ({}) from cache for listing: {}", sorting.toString(), listingId);
}
}
handler = lcache.getHandler(sessionId, listingId);
listingStatus = (handler == null ? ListingStatus.NOT_CACHED : ListingStatus.CACHED);
log.debug("Listing status: {}", listingStatus);
try {
// acquire the listing handler
if(handler == null || listingOp == ListingOp.REFRESH) {
log.debug("Generating listing handler for listing: '{}'...", listingId);
final RemoteListingDefinition<S> listingDef = request.getListingDef();
if(listingDef == null) {
status.addMsg("No listing def specified.", MsgLevel.ERROR, MsgAttr.STATUS.flag);
}
else {
/*
final S search = listingDef.getSearchCriteria();
if(search == null) {
throw new ListingException(listingId, "No search criteria specified.");
}
// translate client side criteria to server side criteria
final Criteria<IEntity> criteria;
try {
// delegate
criteria =
(Criteria<IEntity>) context.getSearchTranslator().translateListingSearchCriteria(context, search);
}
catch(final IllegalArgumentException iae) {
throw new ListingException(listingId, "Unable to translate listing search criteria: "
+ request.descriptor(), iae);
}
// resolve the listing handler data provider
final IListingDataProvider dataProvider =
context.getListingDataProviderResolver().resolve(request);
// resolve the list handler type
final ListHandlerType lht = listingDef.getListHandlerType();
if(lht == null) {
throw new ListingException(listingId, "No list handler type specified.");
}
// resolve the sorting to use
sorting = (sorting == null ? listingDef.getInitialSorting() : sorting);
if(sorting == null) {
throw new ListingException(listingId, "No sorting directive specified.");
}
IListHandler<SearchResult> listHandler = null;
try {
listHandler = ListHandlerFactory.create(criteria, sorting, lht, dataProvider);
}
catch(final InvalidCriteriaException e) {
throw new ListingException(listingId, "Invalid criteria: " + e.getMessage(), e);
}
catch(final EmptyListException e) {
// we proceed to allow client to still show the listing
status.addMsg(e.getMessage(), MsgLevel.WARN, MsgAttr.STATUS.flag);
}
catch(final ListHandlerException e) {
// shouldn't happen
throw new IllegalStateException("Unable to instantiate the list handler: " + e.getMessage(), e);
}
*/
// transform to row list handler
@SuppressWarnings("unchecked")
IListHandler<R> rowListHandler = (IListHandler<R>) context.getRowListHandlerProvider().getRowListHandler(listingDef);
handler = new ListingHandler<R>(rowListHandler, listingId, listingDef.getPageSize());
}
}
// do the query related listing op
if(handler != null && listingOp != null && listingOp.isQuery()) {
log.debug("Performing : '{}' for '{}'", listingOp.getName(), listingId);
try {
handler.query(offset.intValue(), sorting, (listingOp == ListingOp.REFRESH));
status.addMsg(listingOp.getName() + " for '" + listingId + "' successful.", MsgLevel.INFO,
MsgAttr.STATUS.flag);
}
catch(final EmptyListException e) {
// we proceed to allow client to still show the listing
status.addMsg(e.getMessage(), MsgLevel.WARN, MsgAttr.STATUS.flag);
}
catch(final ListingException e) {
throw new ListingException(listingId, "An unexpected error occurred performing listing operation: "
+ e.getMessage(), e);
}
}
}
catch(final ListingException e) {
RpcServlet.exceptionToStatus(e, status);
context.getExceptionHandler().handleException(e);
}
catch(final RuntimeException re) {
context.getExceptionHandler().handleException(re);
throw re;
}
// do caching
if(listingOp == ListingOp.CLEAR) {
// clear
log.debug("Clearing listing '{}'...", listingId);
lcache.clearHandler(sessionId, listingId);
if(!request.getRetainStateOnClear()) {
lcache.clearState(sessionId, listingId);
}
listingStatus = ListingStatus.NOT_CACHED;
status.addMsg("Cleared listing data for " + listingId, MsgLevel.INFO, MsgAttr.STATUS.flag);
}
else if(listingOp == ListingOp.CLEAR_ALL) {
// clear all
log.debug("Clearing ALL listings...");
lcache.clearHandler(sessionId, listingId);
if(!request.getRetainStateOnClear()) {
lcache.clearAll(request.getRetainStateOnClear());
}
listingStatus = ListingStatus.NOT_CACHED;
status.addMsg("Cleared ALL listing data", MsgLevel.INFO, MsgAttr.STATUS.flag);
}
else if(handler != null && !status.hasErrors()) {
// cache listing handler
log.debug("[Re-]Caching listing '{}'...", listingId);
lcache.storeHandler(sessionId, listingId, handler);
// cache listing state
log.debug("[Re-]Caching listing state '{}'...", listingId);
lcache.storeState(sessionId, listingId, new ListingState(Integer.valueOf(handler.getOffset()), handler
.getSorting()));
listingStatus = ListingStatus.CACHED;
}
}
} // !status.hasErrors()
final ListingPayload<R> p = new ListingPayload<R>(status, listingId, listingStatus);
// only provide page data when it is needed at the client and there are no
// errors
if(handler != null && !status.hasErrors() && (listingOp != null && !listingOp.isClear())) {
log.debug("Sending page data for '{}'...", listingId);
p.setPageData(new Page<R>(handler.size(), handler.getPageSize(), handler.getOffset(), handler.getSorting(), handler
.getElements()));
}