Difference between revisions of "Sessions Module"

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=Conventions=
 
=Conventions=
  
* The {{Code|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.
+
* 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 and errors are assigned to the <code><nowiki>http://basex.org/modules/sessions</nowiki></code> namespace. The module must be imported in the query prolog:
+
* 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.
<pre class="brush:xquery">
 
import module namespace sessions = "http://basex.org/modules/sessions";
 
...
 
</pre>
 
 
* 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, <code>[[XQuery Errors#BaseX Errors|basex:http]]</code> is raised.
* If the requested session is not found, <code>[[#Errors|not-found]]</code> 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=
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|-
 
|-
 
| '''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}}.
 
|}
 
|}
  
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|-
 
|-
 
| width='120' | '''Signatures'''
 
| width='120' | '''Signatures'''
|{{Func|sessions:get|$id as xs:string, $key as xs:string|item()*}}<br/>{{Func|sessions:get|$id as xs:string, $key as xs:string, $default as item()*|item()*}}
+
|{{Func|sessions:get|$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|$id}}. If the variable does not exist, or if the key is unknown, an empty sequence or the optionally specified {{Code|$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|get|#Errors}} the value of a session variable could not be retrieved.
 
 
|}
 
|}
  
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|-
 
|-
 
| width='120' | '''Signatures'''
 
| width='120' | '''Signatures'''
|{{Func|sessions:set|$id as xs:string, $key as xs:string, $value as item()*|empty-sequence()}}
+
|{{Func|sessions:set|$id as xs:string, $name as xs:string, $value as item()*|empty-sequence()}}
 
|-
 
|-
 
| '''Summary'''
 
| '''Summary'''
|Binds the specified key/value pair 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'''
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|-
 
|-
 
| width='120' | '''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}}.
 
|}
 
|}
  
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! width="110"|Code
 
! width="110"|Code
 
|Description
 
|Description
|-
 
|{{Code|get}}
 
|The stored attribute is no XQuery value.
 
 
|-
 
|-
 
|{{Code|set}}
 
|{{Code|set}}
|The supplied value cannot be materialized.
+
|The supplied value cannot be stored.
 
|-
 
|-
 
|{{Code|not-found}}
 
|{{Code|not-found}}
|The specified session was not found.
+
|The specified session is not available.
 
|}
 
|}
  
 
=Changelog=
 
=Changelog=
 +
 +
;Version 9.3
 +
* Updated: [[#sessions:get|sessions:get]]: Values that have no XQuery type will be returned as strings.
  
 
;Version 9.0
 
;Version 9.0
 
 
* Updated: error codes updated; errors now use the module namespace
 
* Updated: error codes updated; errors now use the module namespace
  
 
;Version 8.4
 
;Version 8.4
 
 
* Updated: Allow sequences as session values.
 
* Updated: Allow sequences as session values.
  
 
This module was introduced with Version 7.5.
 
This module was introduced with Version 7.5.

Revision as of 11:49, 8 July 2020

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.
  • 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

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 stored.
not-found The specified session is not available.

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.