Session Module

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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 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/session namespace. The module must be imported in the query prolog:
import module namespace session = "http://basex.org/modules/session";
...
  • 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 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

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($key as xs:string) as item()*
session:get($key as xs:string, $default as item()*) as item()*
Summary Returns the value of a variable bound to the current session. 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.
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, $value as item()*) as empty-sequence()
Summary Binds the specified key/value pair to a session.
Errors BXSE0001: a function item was specified as value of a session variable.
Examples Running the server-side XQuery file set.xq via http://localhost:8984/set.xq?key=user&value=john:
import module namespace session = "http://basex.org/modules/session";
session:set($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

Version 8.0
  • Updated: allow sequences as session values

This module was introduced with Version 7.5.