A brief exampe of XQuery 3.0 + Scripting Extensions..

sample-xqsx.xqy

(: A brief exampe of XQuery 3.0 + Scripting Extensions.. :)

(: This example was taken from a Twitter application
 : written in XQuery!
 :)

(: Follow functionality of Twitter :)
declare sequential function twitter:follow-friend()
{
	(: Get the id of user to be followed.. :)
 	declare $user_id :=
 		util:get-request-param("USER_ID");

	(: Check if user session is still valid.. :)
 	declare $is-loggedin as xs:boolean :=
		model:is-loggedin();

	(: Show login if session has expired.. :)
 	if (not($is-isloggedin)) then
		exit returning view:show-login("Session expired")
	else ();

	(: Otherwise update data model.. :)
 	try {

		model:follow-friend($user_id);

	} catch * ($code, $msg, $val) {
		(: Show error message if update fails.. :)
		exit returning view:show-home(concat("ERROR: ", $msg)) 
	};

	(: And update screen on success.. :)
 	view:show-home("Friend added successfully");
};