XWiki Standard 9.8.1 Documentation » Programming Overview » XWiki Platform Plugins Overview

XWiki Platform Plugins Overview

Plugins represented the old way of writing extensions and they were useful when interacting third-party code from the Velocity context. Currently, we are using the XWiki Components.


An XWiki plugin consists of:

  • The plugin itself which implements the XWikiPluginInterface interface. It is also possible to extend the XWikiDefaultPlugin class which is actually an adapter to the "XWikiPluginInterface". The plugin contains the core functionality that are only accessible from scripting provided the user has programming rights.
  • The API that extends the Api class and contains all the public methods that are accessible from scripting. 

Create and Use a Plugin

As explained in the above section, any plugin has 2 parts: the plugin itself and the API. A simple example of a plugin's core functionality is:

package com.xpn.xwiki.plugin.helloworld;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.xpn.xwiki.XWikiContext;
import com.xpn.xwiki.api.Api;
import com.xpn.xwiki.plugin.XWikiDefaultPlugin;
import com.xpn.xwiki.plugin.XWikiPluginInterface;

// The plugin class declaration

public class HelloWorldPlugin extends XWikiDefaultPlugin {

  // Create a "log4j" instance in order to log errors   

  private static Log LOG = LogFactory.getLog(HelloWorldPlugin.class);

  // Constructor

  public HelloWorldPlugin(String name, String className, XWikiContext context) {

  // The method used to retrieve the plugin name

  public String getName() {
    return "helloworld";

   // The method used to retrieve the plugin API which requires a cast

  public Api getPluginApi(XWikiPluginInterface plugin, XWikiContext context) {
    return new HelloWorldPluginApi((HelloWorldPlugin) plugin, context);
  // You can additionally overload the cache flush method

  public void flushCache() {

  // Method for initializing the context
  public void init(XWikiContext context) {

Having a log4j instance for the plugin is very useful for debugging. An example of the logger invocation would be:

public String getName() {
   LOG.debug("Entered method getName");
  return "helloworld";

Next, the API code is:

package com.xpn.xwiki.plugin.helloworld;

import com.xpn.xwiki.XWikiContext;
import com.xpn.xwiki.api.Api;

// The class declaration

public class HelloWorldPluginApi extends Api {
  //The plugin field declaration that will allow the API to call backend methods.

  private HelloWorldPlugin plugin;

  //The constructor

  public HelloWorldPluginApi(HelloWorldPlugin plugin, XWikiContext context) {

  //The plugin getter
  public HelloWorldPlugin getPlugin(){
      return (hasProgrammingRights() ? plugin : null);
      // Uncomment for allowing unrestricted access to the plugin
      // return plugin;

  //The plugin setter  

  public void setPlugin(HelloWorldPlugin plugin) {
      this.plugin = plugin;

  //The API method that can be called from Velocity

  public String hello() {
      return "Hello World!";

  public void updatePage() {

In order to use the plugin, copy your classes to the XWiki "webapps/xwiki/WEB-INF/classes" folder, or copy the JAR file containing the classes in the "webapps/xwiki/WEB-INF/lib" folder. Finally, you need to register the new plugin in the "WEB-INF/xwiki.cfg" file by adding the line 


then restart the server.

To use the plugin in a wiki page, just write "$xwiki.helloworld.hello()" which will display "Hello World!".

XWiki Platform Plugins

Plugins that are in their own JAR

Plugins that are in the XWiki Old Core

Search this space


Most popular tags

Failed to execute the [groovy] macro
  1. access rights
  2. activity stream
  3. annotation
  4. attachment
  5. comment
  6. Document Tree Macro
  7. export
  8. Extension Manager
  9. Flamingo skin
  10. global user
  11. Groovy event listener
  12. group
  13. nested page
  14. search
  15. skin
  16. syntax
  17. user
  18. user profile
  19. velocity macros
  20. wiki
  21. wysiwyg
  22. XWiki Applications
  23. xwikiattachment_archive table
  24. xwikiattachment table
  25. xwikiattrecyclebin table
  26. xwikiproperties table

[Display all tags from this space]