Difference between revisions of "Session Module"
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=Conventions= | =Conventions= | ||
− | * The {{Code|basex-api}} | + | * 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/session</nowiki></code> namespace | + | * All functions and errors are assigned to the <code><nowiki>http://basex.org/modules/session</nowiki></code> namespace, which is statically bound to the {{Code|session}} 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, <code>[[XQuery Errors#BaseX Errors|basex:http]]</code> is raised. | ||
− | * As sessions are side-effecting operations, all functions are flagged as ''non-deterministic''. As a result, | + | * 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 session ID of a servlet request. | |Returns the session ID of a servlet request. | ||
+ | |- | ||
+ | | '''Errors''' | ||
+ | |{{Error|not-found|#Errors}} No session is available for the current client. | ||
|- | |- | ||
| '''Examples''' | | '''Examples''' | ||
|Running the server-side XQuery file {{Code|id.xq}} via <code><nowiki>http://localhost:8984/id.xq</nowiki></code>: | |Running the server-side XQuery file {{Code|id.xq}} via <code><nowiki>http://localhost:8984/id.xq</nowiki></code>: | ||
− | < | + | <syntaxhighlight lang="xquery"> |
import module namespace session = "http://basex.org/modules/session"; | import module namespace session = "http://basex.org/modules/session"; | ||
'Session ID: ' || session:id() | 'Session ID: ' || session:id() | ||
− | </ | + | </syntaxhighlight> |
|} | |} | ||
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| '''Summary''' | | '''Summary''' | ||
|Returns the creation time of a session. | |Returns the creation time of a session. | ||
+ | |- | ||
+ | | '''Errors''' | ||
+ | |{{Error|not-found|#Errors}} No session is available for the current client. | ||
|} | |} | ||
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| '''Summary''' | | '''Summary''' | ||
|Returns the last access time of a session. | |Returns the last access time of a session. | ||
+ | |- | ||
+ | | '''Errors''' | ||
+ | |{{Error|not-found|#Errors}} No session is available for the current client. | ||
|} | |} | ||
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|- | |- | ||
| '''Summary''' | | '''Summary''' | ||
− | |Returns the names of all | + | |Returns the names of all attributes bound to the current session. |
|- | |- | ||
| '''Examples''' | | '''Examples''' | ||
|Running the server-side XQuery file {{Code|names.xq}} via <code><nowiki>http://localhost:8984/names.xq</nowiki></code>: | |Running the server-side XQuery file {{Code|names.xq}} via <code><nowiki>http://localhost:8984/names.xq</nowiki></code>: | ||
− | < | + | <syntaxhighlight lang="xquery"> |
import module namespace session = "http://basex.org/modules/session"; | import module namespace session = "http://basex.org/modules/session"; | ||
session:names() ! element variable { . } | session:names() ! element variable { . } | ||
− | </ | + | </syntaxhighlight> |
|} | |} | ||
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|- | |- | ||
| '''Summary''' | | '''Summary''' | ||
− | |Returns the value of <code>$name</code> | + | |Returns the value of a session attribute with the specified <code>$name</code>. If the attribute is unknown, an empty sequence or the optionally specified {{Code|$default}} value will be returned instead. |
− | |||
− | |||
− | |||
|- | |- | ||
| '''Examples''' | | '''Examples''' | ||
|Running the server-side XQuery file {{Code|get.xq}} via <code><nowiki>http://localhost:8984/get.xq?key=user</nowiki></code>: | |Running the server-side XQuery file {{Code|get.xq}} via <code><nowiki>http://localhost:8984/get.xq?key=user</nowiki></code>: | ||
− | < | + | <syntaxhighlight lang="xquery"> |
import module namespace session = "http://basex.org/modules/session"; | import module namespace session = "http://basex.org/modules/session"; | ||
'Value of ' || $key || ': ' || session:get($key) | 'Value of ' || $key || ': ' || session:get($key) | ||
− | </ | + | </syntaxhighlight> |
|} | |} | ||
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|- | |- | ||
| '''Errors''' | | '''Errors''' | ||
− | |{{Error|set|#Errors}} The supplied value cannot be materialized. | + | |{{Error|set|#Errors}} The supplied value cannot be materialized.<br/>{{Error|not-found|#Errors}} No session is available for the current client. |
|- | |- | ||
| '''Examples''' | | '''Examples''' | ||
|Running the server-side XQuery file {{Code|set.xq}} via <code><nowiki>http://localhost:8984/set.xq?key=user&value=john</nowiki></code>: | |Running the server-side XQuery file {{Code|set.xq}} via <code><nowiki>http://localhost:8984/set.xq?key=user&value=john</nowiki></code>: | ||
− | < | + | <syntaxhighlight lang="xquery"> |
import module namespace session = "http://basex.org/modules/session"; | import module namespace session = "http://basex.org/modules/session"; | ||
session:set($key, $value), 'Variable was set.' | session:set($key, $value), 'Variable was set.' | ||
− | </ | + | </syntaxhighlight> |
|} | |} | ||
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|- | |- | ||
| '''Summary''' | | '''Summary''' | ||
− | |Deletes a session | + | |Deletes a session attribute with the specified <code>$name</code>. |
|- | |- | ||
| '''Examples''' | | '''Examples''' | ||
|Running the server-side XQuery file {{Code|delete.xq}} via <code><nowiki>http://localhost:8984/delete.xq?key=user</nowiki></code>: | |Running the server-side XQuery file {{Code|delete.xq}} via <code><nowiki>http://localhost:8984/delete.xq?key=user</nowiki></code>: | ||
− | < | + | <syntaxhighlight lang="xquery"> |
import module namespace session = "http://basex.org/modules/session"; | import module namespace session = "http://basex.org/modules/session"; | ||
session:delete($key), 'Variable was deleted.' | session:delete($key), 'Variable was deleted.' | ||
− | </ | + | </syntaxhighlight> |
|} | |} | ||
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{| class="wikitable" width="100%" | {| class="wikitable" width="100%" | ||
− | ! width="110" |Code | + | ! width="110"|Code |
|Description | |Description | ||
|- | |- | ||
− | |{{Code| | + | |{{Code|set}} |
− | |The stored | + | |The supplied value cannot be stored. |
|- | |- | ||
− | |{{Code| | + | |{{Code|not-found}} |
− | | | + | |No session is available for the current client. |
|} | |} | ||
=Changelog= | =Changelog= | ||
+ | |||
+ | ;Version 9.4 | ||
+ | * Updated: Only create session if required. | ||
+ | |||
+ | ;Version 9.3 | ||
+ | * Updated: [[#session:get|session: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 8.0 | ;Version 8.0 | ||
− | |||
* 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 12:50, 8 July 2020
This XQuery Module contains functions for accessing and modifying server-side session information. This module is mainly useful in the context of Web Applications.
Contents
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 thesession
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. |
Errors | not-found : No session is available for the current client.
|
Examples | Running the server-side XQuery file id.xq via http://localhost:8984/id.xq :
<syntaxhighlight lang="xquery"> import module namespace session = "http://basex.org/modules/session"; 'Session ID: ' || session:id() </syntaxhighlight> |
session:created
Signatures | session:created() as xs:dateTime
|
Summary | Returns the creation time of a session. |
Errors | not-found : No session is available for the current client.
|
session:accessed
Signatures | session:accessed() as xs:dateTime
|
Summary | Returns the last access time of a session. |
Errors | not-found : No session is available for the current client.
|
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 :
<syntaxhighlight lang="xquery"> import module namespace session = "http://basex.org/modules/session"; session:names() ! element variable { . } </syntaxhighlight> |
session:get
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 :
<syntaxhighlight lang="xquery"> import module namespace session = "http://basex.org/modules/session"; 'Value of ' || $key || ': ' || session:get($key) </syntaxhighlight> |
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 $name .
|
Errors | set : The supplied value cannot be materialized.not-found : No session is available for the current client.
|
Examples | Running the server-side XQuery file set.xq via http://localhost:8984/set.xq?key=user&value=john :
<syntaxhighlight lang="xquery"> import module namespace session = "http://basex.org/modules/session"; session:set($key, $value), 'Variable was set.' </syntaxhighlight> |
session:delete
Signatures | session:delete($name as xs:string) as empty-sequence()
|
Summary | Deletes a session attribute with the specified $name .
|
Examples | Running the server-side XQuery file delete.xq via http://localhost:8984/delete.xq?key=user :
<syntaxhighlight lang="xquery"> import module namespace session = "http://basex.org/modules/session"; session:delete($key), 'Variable was deleted.' </syntaxhighlight> |
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 stored. |
not-found
|
No session is available for the current client. |
Changelog
- Version 9.4
- Updated: Only create session if required.
- 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.