@Override
public Value value(final QueryContext qc) throws QueryException {
if (seqType().zeroOrOne()) {
final Value v = item(qc, info);
return v == null ? Empty.SEQ : v;
}
return qc.iter(this).value();
}
/**
* Evaluates the specified function and creates a response.
*
* @throws Exception exception (including unexpected ones)
*/
void create() throws Exception {
// bind variables
final StaticFunc sf = function.function;
final Expr[] args = new Expr[sf.args.length];
function.bind(http, args, error);
// wrap function with a function call
final MainModule mm = new MainModule(sf, args);
// assign main module and http context and register process
query.mainModule(mm);
query.http(http);
query.context.register(query);
String redirect = null, forward = null;
RestXqRespBuilder resp = null;
try {
// compile and evaluate query
query.compile();
final Iter iter = query.iter();
Item item = iter.next();
// handle response element
if (item != null && item instanceof ANode) {
final ANode node = (ANode) item;
// send redirect to browser
if (REST_REDIRECT.eq(node)) {
final ANode ch = node.children().next();
if (ch == null || ch.type != NodeType.TXT) throw function.error(NO_VALUE, node.name());
redirect = string(ch.string()).trim();
return;
}
// server-side forwarding
if (REST_FORWARD.eq(node)) {
final ANode ch = node.children().next();
if (ch == null || ch.type != NodeType.TXT) throw function.error(NO_VALUE, node.name());
forward = string(ch.string()).trim();
return;
}
if (REST_RESPONSE.eq(node)) {
resp = new RestXqRespBuilder();
resp.build(node, function, iter, http);
return;
}
}
// HEAD method must return a single response element
if (function.methods.size() == 1 && function.methods.contains(HTTPMethod.HEAD.name()))
throw function.error(HEAD_METHOD);
// serialize result
final SerializerOptions sp = function.output;
http.sopts(sp);
http.initResponse();
final Serializer ser = Serializer.get(http.res.getOutputStream(), sp);
for (; item != null; item = iter.next()) ser.serialize(item);
ser.close();
} finally {
query.close();
query.context.unregister(query);
if (redirect != null) {
http.res.sendRedirect(redirect);
} else if (forward != null) {
http.req.getRequestDispatcher(forward).forward(http.req, http.res);
} else if (resp != null) {
if (resp.status != 0) http.status(resp.status, resp.message, resp.error);
http.res.getOutputStream().write(resp.cache.toArray());
}
}
}