XQuery Extension Modules Documentation

Introduction

eXist-db provides a pluggable module interface that allows extension modules to be easily developed in Java. These extension modules can provide additional XQuery functions through a custom namespace. The extension modules have full access to the eXist-db database, its internal API, the context of the executing XQuery and the HTTP Session (if appropriate).

The source code for extension modules should be placed in their own folder inside $EXIST_HOME/extensions/modules/src/org/exist/xquery/modules. They may then be compiled in place using either $EXIST_HOME/build.sh extension-modules or %EXIST_HOME%\build.bat extension-modules depending on the platform.

Modules associated to modularized indexes should be placed in the $EXIST_HOME/extensions/indexes/*/xquery/modules/* hierarchy. They will be compiled automatically by the standard build targets or as indicated above.

eXist-db must also be told which modules to load, this is done in conf.xml and the Class name and Namespace for each module is listed below. Note – eXist-db will require a restart to load any new modules added. Once a Module is configured and loaded eXist-db will display the module and its function definitions as part of the function library page or through util:decribe-function().

Example Module

Demonstrates the simplest example of an Extension module with a single function. A good place to start if you wish to develop your own Extension Module.

Creator: Wolfgang MeierLicence: LGPL Status: production

Class: org.exist.xquery.modules.example.ExampleModule Namespace: http://exist-db.org/xquery/examples

Cache Module

Provides a global key/value cache

Creator: Evgeny GazdovskyLicence: LGPL Status: production

Class: org.exist.xquery.modules.cache.CacheModule Namespace: http://exist-db.org/xquery/cache

Compression Module

Provides additional operations for compression

Creator: Adam RetterLicence: LGPL Status: production

Class: org.exist.xquery.modules.compression.CompressionModule Namespace: http://exist-db.org/xquery/compression

Context Module

Provides access to XQuery contexts, local attributes and foreign contexts for simple inter-XQuery communication. This extension is experimental at this time and has side effects (eg. not purely functional in nature). Use at own risk!

Creator: Andrzej TaraminaLicence: LGPL Status: experimental

Class: org.exist.xquery.modules.context.ContextModule Namespace: http://exist-db.org/xquery/context

Date Time Module

Provides additional operations on date and time types

Creator: Adam RetterLicence: LGPL Status: production

Class: org.exist.xquery.modules.datetime.DateTimeModule Namespace: http://exist-db.org/xquery/datetime

EXI Module

Provides additional operations to encode and decode Efficient XML Interchange format (EXI)

Creator: Robert WalpoleLicence: LGPL Status: production

Class: org.exist.xquery.modules.exi.EXIModule Namespace: http://exist-db.org/xquery/exi

File Module

Provides additional operations on files and directories. WARNING: Enabling this extension module could result in possible security issues, since it allows writing to the filesystem by xqueries!

Creator: Andrzej Taramina, Chaeron CorporationLicence: LGPL Status: production

Class: org.exist.xquery.modules.file.FileModule Namespace: http://exist-db.org/xquery/file

HTTP Client Module

Functions for performing HTTP requests

Creator: Adam Retter and Andrzej TaraminaLicence: LGPL Features Used: NekoHTML Status: production

Class: org.exist.xquery.modules.http.HTTPClientModule Namespace: http://exist-db.org/xquery/httpclient

Image Module

This modules provides operations on images stored in the db, including: Retreiving Image Dimensions, Creating Thumbnails and Resizing Images.

Creator: Adam RetterContributors: Wolfgang Meier, Rafael TroiloLicence: LGPL Status: production

Class: org.exist.xquery.modules.image.ImageModule Namespace: http://exist-db.org/xquery/image

JNDI Directory Module

This extension module allows you to access and manipulate JNDI-based directories, such as LDAP, using XQuery functions. It can be very useful if you want to integration and LDAP directory into an eXist-db/XQuery based application.

To compile it, set the parameter include.module.jndi = true in $EXIST_HOME/extensions/local.build.properties file (create it if missing).

Then, to enable it, edit the appropriate module entry in conf.xml

Creator: Andrzej Taramina, Chaeron CorporationLicence: LGPL Status: production

Class: org.exist.xquery.modules.jndi.JNDIModule Namespace: http://exist-db.org/xquery/jndi

Mail Module

This modules provides facilities for sending text and/or HTML emails from XQuery using either SMTP or a local Sendmail binary.

Creator: Adam RetterContributors: Robert WalpoleLicence: LGPL Status: production

Class: org.exist.xquery.modules.mail.MailModule Namespace: http://exist-db.org/xquery/mail

Math Module

This module provides mathematical functions from the java Math class.

Creator: Dannes WesselsLicence: LGPL Status: production

Class: org.exist.xquery.modules.math.MathModule Namespace: http://exist-db.org/xquery/math

Oracle Module

This module allows execution of PL/SQL Stored Procedures within an Oracle RDBMS from XQuery and returns the results as XML nodes. This module should be used where an Oracle database returns results in an Oracle REF_CURSOR and can only be used in conjunction with the SQL extension module.

Creator: Rob WalpoleLicence: LGPL Status: production

Class: org.exist.xquery.modules.oracle.OracleModule Namespace: http://exist-db.org/xquery/oracle

Scheduler Module

Provides access to eXist-db's Scheduler for the purposes of scheduling job's and manipulating existing job's.

Creator: Adam RetterLicence: LGPL Status: production

Class: org.exist.xquery.modules.scheduler.SchedulerModule Namespace: http://exist-db.org/xquery/scheduler

Simple Query Language Module

This modules implements a Simple custom Query Language which is then converted to XPath and executed against the db.

Creator: Wolfgang MeierLicence: LGPL Status: production

Class: org.exist.xquery.modules.simpleql.SimpleQLModule Namespace: http://exist-db.org/xquery/simple-ql

Spatial module

Various functions for GML geometries, whether indexed or not. More information about the design is available here.

Creator: Pierrick BrihayeLicence: LGPL Status: experimental

Class: org.exist.xquery.modules.spatial.SpatialModule Namespace: http://exist-db.org/xquery/spatial

SQL Module

This module provides facilities for performing SQL operations against traditional databases from XQuery and returning the results as XML nodes.

Creator: Adam RetterLicence: LGPL Features Used: JDBC Status: production

Class: org.exist.xquery.modules.sql.SQLModule Namespace: http://exist-db.org/xquery/sql

XML Differencing Module

This module provides facilities for determining the differences between XML nodes.

Creator: Dannes WesselsContributors: Pierrick BrihayeLicence: LGPL Status: production

Class: org.exist.xquery.modules.xmldiff.XmlDiffModule Namespace: http://exist-db.org/xquery/xmldiff

XSL-FO Module

This module provides XSL-FO rendering facilities.

Creator: University of the West of England Licence: LGPL Features Used: Apache FOPStatus: production

Class: org.exist.xquery.modules.xslfo.XSLFOModule Namespace: http://exist-db.org/xquery/xslfo

XProcxq Module

This module provides XProc functionality to eXist-db.

Creator: James R. Fuller Licence: MPL v1.1 Features Used: expath http libraryStatus: in development for v2.0 release

Class: static xquery module via extensions/xprocxq.jar Namespace: http://xproc.net/xproc

XML Calabash Module

This module provides simple integration with XML Calabash XProc engine.

Creator: James R. Fuller Licence: MPL v1.1

Class: org.exist.xquery.modules.xmlcalabash Namespace:  http://xmlcalabash.com