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
As sessions are side-effecting operations, all functions in this module are flagged as non-deterministic. This means that the evaluation order of the functions will not be influenced by the compiler.
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.
Functions
session:id
Signatures
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session:id() as xs:string
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Summary
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Returns the session ID of a servlet request.
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Examples
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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()
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session:names
Signatures
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session:names() as xs:string*
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Summary
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Returns the names of all variables bound to the current session.
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Examples
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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 { . }
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session:get
Signatures
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session:get($key as xs:string) as xs:string?
session:get($key as xs:string, $default as xs:string) as xs:string
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Summary
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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.
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Errors
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BXSE0002 : the value of a session variable could not be retrieved.
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Examples
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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)
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session:set
Signatures
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session:set($key as xs:string, $value as xs:string) as empty-sequence()
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Summary
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Assigns a value to a session variable.
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Errors
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BXSE0001 : a function item was specified as value of a session variable.
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Examples
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Running the server-side XQuery file set.xq via http://localhost:8984/set.xq?key=user&value=john :
import module namespace session = "http://basex.org/modules/session";
session:set($key, $value), 'Variable was set.'
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session:delete
Signatures
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session:delete($key as xs:string) as empty-sequence()
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Summary
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Deletes a session variable.
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Examples
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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.'
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session:close
Signatures
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session:close() as empty-sequence()
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Summary
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Unregisters a session and all data associated with it.
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Errors
Code
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Description
|
BXSE0001
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A function item was specified as value of a session attribute.
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BXSE0002
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An error occurred while retrieving the value of a session attribute.
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Changelog
This module was introduced with Version 7.5.