Difference between revisions of "Sessions Module"

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=Conventions=
 
=Conventions=
 +
 +
{{Mark|Updated with Version 9.0}}:
  
 
* 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 {{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.
−
* All functions 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 to the <code><nowiki>http://basex.org/modules/sessions</nowiki></code> namespace. The module must 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";
 
...
 
...
 
</pre>
 
</pre>
−
* In this documentation, the namespace is bound to the {{Code|sessions}} prefix.
+
* If any of the functions is called outside the servlet context, the error {{Error|basex:http|XQuery Errors#BaseX Errors}} is raised.
−
* Errors are assigned to the <code><nowiki>http://basex.org/errors</nowiki></code> namespace, which is statically bound to the {{Code|bxerr}} prefix.
+
* If the requested session is not found, the error {{Error|not-found|#Errors}} is raised.
−
* If any of the functions is called outside the servlet context, the error {{Error|BXSE0003|#Errors}} 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''. This means that the functions will not be reordered by the compiler.
  
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==sessions:ids==
 
==sessions:ids==
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
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==sessions:created==
 
==sessions:created==
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
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==sessions:accessed==
 
==sessions:accessed==
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
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==sessions:names==
 
==sessions:names==
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
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|-
 
|-
 
| '''Errors'''
 
| '''Errors'''
−
|{{Error|BXSE0002|#Errors}} the value of a session variable could not be retrieved.
+
|{{Error|get|#Errors}} the value of a session variable could not be retrieved.
 
|}
 
|}
  
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|-
 
|-
 
| '''Errors'''
 
| '''Errors'''
−
|{{Error|BXSE0001|#Errors}} a function item was specified as value of a session variable.
+
|{{Error|set|#Errors}} a function item was specified as value of a session variable.
 
|}
 
|}
  
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==sessions:close==
 
==sessions:close==
 +
 
{| width='100%'
 
{| width='100%'
 
|-
 
|-
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=Errors=
 
=Errors=
 +
 +
{{Mark|Updated with Version 9.0}}:
  
 
{| class="wikitable" width="100%"
 
{| class="wikitable" width="100%"
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|Description
 
|Description
 
|-
 
|-
−
|{{Code|BXSE0001}}
+
|{{Code|set}}
−
|A function item was specified as value of a session attribute.
+
|Function items cannot be stored.
 
|-
 
|-
−
|{{Code|BXSE0002}}
+
|{{Code|get}}
−
|An error occurred while retrieving the value of a session attribute.
+
|The stored attribute is no XQuery value.
 
|-
 
|-
−
|{{Code|BXSE0003}}
+
|{{Code|not-found}}
−
|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 9.0
 +
 +
* 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 20:15, 21 November 2017

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

Template:Mark:

  • 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 and errors are assigned to the http://basex.org/modules/sessions namespace. The module must 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, the error basex:http: is raised.
  • If the requested session is not found, the error not-found: 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

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 variables bound to the session specified by $id.

sessions:get

Signatures sessions:get($id as xs:string, $key as xs:string) as item()*
sessions:get($id as xs:string, $key as xs:string, $default as item()*) as item()*
Summary Returns the value of a variable bound to the session specified by $id. If the variable does not exist, or if the key is unknown, an empty sequence or the optionally specified default value is returned instead.
Errors get: the value of a session variable could not be retrieved.

sessions:set

Signatures sessions:set($id as xs:string, $key as xs:string, $value as item()*) as empty-sequence()
Summary Binds the specified key/value pair to the session specified by $id.
Errors set: a function item was specified as value of a session variable.

sessions:delete

Signatures sessions:delete($id as xs:string, $key as xs:string) as empty-sequence()
Summary Deletes a variable bound to the session specified by $id.

sessions:close

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

Errors

Template:Mark:

Code Description
set Function items cannot be stored.
get The stored attribute is no XQuery value.
not-found The specified session was not found.

Changelog

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.

Retrieved from "http://docs.basex.org/index.php?title=Sessions_Module&oldid=13537"