Sessions Module

This XQuery Module can only be called from users with Admin permissions. It contains functions for accessing and modifying all registered server-side sessions. This module is mainly useful in the context of Web Applications.

Conventions

• The basex-api package must be included in the classpath. This is always the case if you use one of the complete distributions (zip, exe, war) of BaseX.
• All functions are assigned to the http://basex.org/modules/sessions namespace. The module must be imported in the query prolog:

import module namespace sessions = "http://basex.org/modules/sessions";
...

• In this documentation, the namespace is bound to the sessions prefix.
• Errors are assigned to the http://basex.org/errors namespace, which is statically bound to the bxerr prefix.
• If any of the functions is called outside the servlet context, the error BXSE0003: is raised.
• As sessions are side-effecting operations, all functions are flagged as non-deterministic. This means that the functions will not be reordered by the compiler.

Functions

sessions:ids

Signatures	sessions:ids() as xs:string
Summary	Returns the IDs of all registered sessions.

sessions:created

Signatures	sessions:created($id as xs:string) as xs:dateTime
Summary	Returns the creation time of the session specified by $id.

sessions:accessed

Signatures	sessions:accessed($id as xs:string) as xs:dateTime
Summary	Returns the last access time of the session specified by $id.

sessions:names

Signatures	sessions:names($id as xs:string) as xs:string*
Summary	Returns the names of all variables bound to the session specified by $id.

sessions:get

Signatures	sessions:get($id as xs:string, $key as xs:string) as item()* sessions:get($id as xs:string, $key as xs:string, $default as item()*) as item()*
Summary	Returns the value of a variable bound to the session specified by $id. If the variable does not exist, or if the key is unknown, an empty sequence or the optionally specified default value is returned instead.
Errors	BXSE0002: the value of a session variable could not be retrieved.

sessions:set

Signatures	sessions:set($id as xs:string, $key as xs:string, $value as item()*) as empty-sequence()
Summary	Binds the specified key/value pair to the session specified by $id.
Errors	BXSE0001: a function item was specified as value of a session variable.

sessions:delete

Signatures	sessions:delete($id as xs:string, $key as xs:string) as empty-sequence()
Summary	Deletes a variable bound to the session specified by $id.

sessions:close

Signatures	sessions:close($id as xs:string) as empty-sequence()
Summary	Unregisters the session specified by $id.

Errors

Code	Description
BXSE0001	A function item was specified as value of a session attribute.
BXSE0002	An error occurred while retrieving the value of a session attribute.
BXSE0003	A function was called outside the servlet context.
BXSE0004	The specified session was not found.

Changelog

Version 8.4

• Updated: Allow sequences as session values.

This module was introduced with Version 7.5.