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 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.
  • 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

Updated with Version 9.3: Values that have no XQuery type will be returned as strings.

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.
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
set The supplied value cannot be materialized.

Changelog

Version 9.3
  • Updated: session:get: Values that have no XQuery type will be returned as strings.
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.