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

This module is included in the complete distributions (zip, exe, war) of BaseX.

All functions are assigned to the http://basex.org/modules/session namespace, which must be dynamically imported. In this documentation, the namespace is bound to the session prefix. Errors are assigned to the http://basex.org/errors namespace, which is statically bound to the bxerr prefix.

If the module 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

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 variables 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($key as xs:string) as xs:string? session:get($key as xs:string, $default as xs:string) as xs:string
Summary	Returns the value of a variable bound to the current session. If the variable does not exist, an empty sequence or the optionally specified default value is returned instead.
Errors	BXSE0002: the value of a session variable 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($key as xs:string, $value as xs:string) as empty-sequence()
Summary	Assigns a value to a session variable.
Errors	BXSE0001: a function item was specified as value of a session variable.
Examples	Running the server-side XQuery file set.xq via http://localhost:8984/set.xq?key=user&value=john: import module namespace session = "http://basex.org/modules/session"; session:set($key, $value), 'Variable was set.'

session:delete

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

Changelog

This module was introduced with Version 7.5.