Session Module

This XQuery Module contains functions for accessing and modifying server-side session information. 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 to the http://basex.org/modules/session namespace, which is statically bound to the session prefix. Prior to Version 9.2, the module needed to be imported in the query prolog:

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

• If any of the functions is called outside the servlet context, basex:http 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

session:id

Signatures	session:id() as xs:string
Summary	Returns the session ID of a servlet request.
Examples	Running the server-side XQuery file id.xq via http://localhost:8984/id.xq: import module namespace session = "http://basex.org/modules/session"; 'Session ID: ' || session:id()

session:created

Signatures	session:created() as xs:dateTime
Summary	Returns the creation time of a session.

session:accessed

Signatures	session:accessed() as xs:dateTime
Summary	Returns the last access time of a session.

session:names

Signatures	session:names() as xs:string*
Summary	Returns the names of all attributes bound to the current session.
Examples	Running the server-side XQuery file names.xq via http://localhost:8984/names.xq: import module namespace session = "http://basex.org/modules/session"; session:names() ! element variable { . }

session:get

Signatures	session:get($name as xs:string) as item()* session:get($name as xs:string, $default as item()*) as item()*
Summary	Returns the value of a session attribute with the specified $name. 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.
Examples	Running the server-side XQuery file get.xq via http://localhost:8984/get.xq?key=user: import module namespace session = "http://basex.org/modules/session"; 'Value of ' || $key || ': ' || session:get($key)

session:set

Signatures	session:set($name as xs:string, $value as item()*) as empty-sequence()
Summary	Binds the specified $value to the session attribute with the specified $name.
Errors	set: The supplied value cannot be materialized.
Examples	Running the server-side XQuery file set.xq via http://localhost:8984/set.xq?key=user&value=john: import module namespace session = "http://basex.org/modules/session"; session:set($key, $value), 'Variable was set.'

session:delete

Signatures	session:delete($name as xs:string) as empty-sequence()
Summary	Deletes a session attribute with the specified $name.
Examples	Running the server-side XQuery file delete.xq via http://localhost:8984/delete.xq?key=user: import module namespace session = "http://basex.org/modules/session"; session:delete($key), 'Variable was deleted.'

session:close

Signatures	session:close() as empty-sequence()
Summary	Unregisters a session and all data associated with it.

Errors

Code	Description
get	The stored attribute is no XQuery value.
set	The supplied value cannot be materialized.

Changelog

Version 9.0

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

Version 8.0

• Updated: Allow sequences as session values.

This module was introduced with Version 7.5.