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 module will be available if the basex-api library is found in the classpath. This is the case if you use one of the complete distributions of BaseX (zip, exe, war).
• All functions and errors are assigned of 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 document, the namespace is bound to the sessions prefix.
• If any of the functions is called outside the servlet context, basex:http is raised.
• If a specified session id is not found, not-found is raised.
• As sessions are side-effecting operations, all functions are flagged as non-deterministic. As a result, some query optimizations will be suppressed.

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, $name as xs:string) as item()* sessions:get($id as xs:string, $name as xs:string, $default as item()*) as item()*
Summary	Returns the value of an attribute with the specified $name from the session with the specified $id. If the attribute is unknown, an empty sequence or the optionally specified $default value will be returned instead.
Errors	get: the value of an attribute could not be retrieved.

sessions:set

Signatures	sessions:set($id as xs:string, $name as xs:string, $value as item()*) as empty-sequence()
Summary	Returns the specified value to the attribute with the specified $name from the session with the specified $id.
Errors	set: The supplied value cannot be materialized.

sessions:delete

Signatures	sessions:delete($id as xs:string, $name as xs:string) as empty-sequence()
Summary	Deletes an attribute with the specified $name from the session with the specified $id.

sessions:close

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

Errors

Code	Description
get	The stored attribute is no XQuery value.
set	The supplied value cannot be materialized.
not-found	The specified session was not found.

Changelog

Version 9.0

• Updated: error codes updated; errors now use the module namespace

Version 8.4

• Updated: Allow sequences as session values.

This module was introduced with Version 7.5.