Difference between revisions of "Sessions Module"

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=Conventions=
 
=Conventions=
  
* This module is included in the complete distributions (zip, exe, war) of BaseX.
+
* The module will be available if the {{Code|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 are assigned to the {{Code|http://basex.org/modules/sessions}} namespace, which must be dynamically imported:
+
* All functions and errors are assigned of the <code><nowiki>http://basex.org/modules/sessions</nowiki></code> namespace, which is statically bound to the {{Code|sessions}} prefix. Prior to {{Version|9.2}}, the module needed to be imported in the query prolog:
 
<pre class="brush:xquery">
 
<pre class="brush:xquery">
 
import module namespace sessions = "http://basex.org/modules/sessions";
 
import module namespace sessions = "http://basex.org/modules/sessions";
 
...
 
...
* In this documentation, the namespace is bound to the {{Code|sessions}} prefix.
+
</pre>
* Errors are assigned to the {{Code|http://basex.org/errors}} namespace, which is statically bound to the {{Code|bxerr}} prefix.
+
* If any of the functions is called outside the servlet context, <code>[[XQuery Errors#BaseX Errors|basex:http]]</code> is raised.
* If any of the functions is called outside the servlet context, the error [[#BXSE0003|BXSE0003]] is raised.
+
* If a specified session id is not found, <code>[[#Errors|not-found]]</code> 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.
+
* As sessions are side-effecting operations, all functions are flagged as ''non-deterministic''. As a result, some query optimizations will be suppressed.
  
 
=Functions=
 
=Functions=
  
 
==sessions:ids==
 
==sessions:ids==
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
| width='90' | '''Signatures'''
+
| width='120' | '''Signatures'''
|{{Func|sessions:ids||xs:string}}
+
|{{Func|sessions:ids||xs:string*}}
 
|-
 
|-
 
| '''Summary'''
 
| '''Summary'''
Line 26: Line 27:
  
 
==sessions:created==
 
==sessions:created==
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
| width='90' | '''Signatures'''
+
| width='120' | '''Signatures'''
 
|{{Func|sessions:created|$id as xs:string|xs:dateTime}}
 
|{{Func|sessions:created|$id as xs:string|xs:dateTime}}
 
|-
 
|-
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==sessions:accessed==
 
==sessions:accessed==
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
| width='90' | '''Signatures'''
+
| width='120' | '''Signatures'''
 
|{{Func|sessions:accessed|$id as xs:string|xs:dateTime}}
 
|{{Func|sessions:accessed|$id as xs:string|xs:dateTime}}
 
|-
 
|-
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==sessions:names==
 
==sessions:names==
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
| width='90' | '''Signatures'''
+
| width='120' | '''Signatures'''
 
|{{Func|sessions:names|$id as xs:string|xs:string*}}
 
|{{Func|sessions:names|$id as xs:string|xs:string*}}
 
|-
 
|-
 
| '''Summary'''
 
| '''Summary'''
|Returns the names of all variables bound to the session specified by {{Mono|$id}}.
+
|Returns the names of all attributes bound to the session specified by {{Mono|$id}}.
 
|}
 
|}
  
 
==sessions:get==
 
==sessions:get==
 +
 +
{{Mark|Updated with Version 9.3:}} Values that have no XQuery type will be returned as strings.
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
| width='90' | '''Signatures'''
+
| width='120' | '''Signatures'''
|{{Func|sessions:get|$id as xs:string, $key as xs:string|xs:string?}}<br/>{{Func|sessions:get|$id as xs:string, $key as xs:string, $default as xs:string|xs:string}}
+
|{{Func|sessions:get|$id as xs:string, $name as xs:string|item()*}}<br/>{{Func|sessions:get|$id as xs:string, $name as xs:string, $default as item()*|item()*}}
 
|-
 
|-
 
| '''Summary'''
 
| '''Summary'''
|Returns the value of a variable bound to the session specified by {{Mono|$id}}. If the variable does not exist, an empty sequence or the optionally specified default value is returned instead.
+
|Returns the value of an attribute with the specified {{Code|$name}} from the session with the specified {{Mono|$id}}. If the attribute is unknown, an empty sequence or the optionally specified {{Code|$default}} value will be returned instead.
|-
 
| '''Errors'''
 
|{{Error|BXSE0002|#Errors}} the value of a session variable could not be retrieved.
 
 
|}
 
|}
  
 
==sessions:set==
 
==sessions:set==
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
| width='90' | '''Signatures'''
+
| width='120' | '''Signatures'''
|{{Func|sessions:set|$id as xs:string, $key as xs:string, $value as xs:string|empty-sequence()}}
+
|{{Func|sessions:set|$id as xs:string, $name as xs:string, $value as item()*|empty-sequence()}}
 
|-
 
|-
 
| '''Summary'''
 
| '''Summary'''
|Assigns a value to a variable bound to the session specified by {{Mono|$id}}.
+
|Returns the specified {{Code|value}} to the attribute with the specified {{Code|$name}} from the session with the specified {{Mono|$id}}.
 
|-
 
|-
 
| '''Errors'''
 
| '''Errors'''
|{{Error|BXSE0001|#Errors}} a function item was specified as value of a session variable.
+
|{{Error|set|#Errors}} The supplied value cannot be materialized.
 
|}
 
|}
  
 
==sessions:delete==
 
==sessions:delete==
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
| width='90' | '''Signatures'''
+
| width='120' | '''Signatures'''
|{{Func|sessions:delete|$id as xs:string, $key as xs:string|empty-sequence()}}
+
|{{Func|sessions:delete|$id as xs:string, $name as xs:string|empty-sequence()}}
 
|-
 
|-
 
| '''Summary'''
 
| '''Summary'''
|Deletes a variable bound to the session specified by {{Mono|$id}}.
+
|Deletes an attribute with the specified {{Code|$name}} from the session with the specified {{Mono|$id}}.
 
|}
 
|}
  
 
==sessions:close==
 
==sessions:close==
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
| width='90' | '''Signatures'''
+
| width='120' | '''Signatures'''
 
|{{Func|sessions:close|$id as xs:string|empty-sequence()}}
 
|{{Func|sessions:close|$id as xs:string|empty-sequence()}}
 
|-
 
|-
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=Errors=
 
=Errors=
  
{| width='100%' class="wikitable" width="100%"
+
{| class="wikitable" width="100%"
! width="5%"|Code
+
! width="110"|Code
! width="95%"|Description
+
|Description
 
|-
 
|-
|{{Code|BXSE0001}}
+
|{{Code|set}}
|A function item was specified as value of a session attribute.
+
|The supplied value cannot be materialized.
 
|-
 
|-
|{{Code|BXSE0002}}
+
|{{Code|not-found}}
|An error occurred while retrieving the value of a session attribute.
 
|-
 
|{{Code|BXSE0003}}
 
|A function was called outside the servlet context.
 
|-
 
|{{Code|BXSE0004}}
 
 
|The specified session was not found.
 
|The specified session was not found.
 
|}
 
|}
  
 
=Changelog=
 
=Changelog=
 +
 +
;Version 9.3
 +
 +
* Updated: [[#sessions:get|sessions: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 8.4
 +
 +
* Updated: Allow sequences as session values.
  
 
This module was introduced with Version 7.5.
 
This module was introduced with Version 7.5.
 
[[Category:XQuery]]
 

Revision as of 12:29, 11 July 2019

This XQuery Module can only be called from users with Admin permissions. It contains functions for accessing and modifying all registered server-side sessions. 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 of the http://basex.org/modules/sessions namespace, which is statically bound to the sessions prefix. Prior to Version 9.2, the module needed to be imported in the query prolog:
import module namespace sessions = "http://basex.org/modules/sessions";
...
  • If any of the functions is called outside the servlet context, basex:http is raised.
  • If a specified session id is not found, not-found 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

sessions:ids

Signatures sessions:ids() as xs:string*
Summary Returns the IDs of all registered sessions.

sessions:created

Signatures sessions:created($id as xs:string) as xs:dateTime
Summary Returns the creation time of the session specified by $id.

sessions:accessed

Signatures sessions:accessed($id as xs:string) as xs:dateTime
Summary Returns the last access time of the session specified by $id.

sessions:names

Signatures sessions:names($id as xs:string) as xs:string*
Summary Returns the names of all attributes bound to the session specified by $id.

sessions:get

Template:Mark Values that have no XQuery type will be returned as strings.

Signatures sessions:get($id as xs:string, $name as xs:string) as item()*
sessions:get($id as xs:string, $name as xs:string, $default as item()*) as item()*
Summary Returns the value of an attribute with the specified $name from the session with the specified $id. If the attribute is unknown, an empty sequence or the optionally specified $default value will be returned instead.

sessions:set

Signatures sessions:set($id as xs:string, $name as xs:string, $value as item()*) as empty-sequence()
Summary Returns the specified value to the attribute with the specified $name from the session with the specified $id.
Errors set: The supplied value cannot be materialized.

sessions:delete

Signatures sessions:delete($id as xs:string, $name as xs:string) as empty-sequence()
Summary Deletes an attribute with the specified $name from the session with the specified $id.

sessions:close

Signatures sessions:close($id as xs:string) as empty-sequence()
Summary Unregisters the session specified by $id.

Errors

Code Description
set The supplied value cannot be materialized.
not-found The specified session was not found.

Changelog

Version 9.3
  • Updated: sessions: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 8.4
  • Updated: Allow sequences as session values.

This module was introduced with Version 7.5.