UIExtension Module

Defines a way to add User Interface Extensions to the XWiki platform

Description

Introduction

XWiki has evolved into a platform made of a collection of modules. The User Interface of those modules are made of wiki pages. Those modules can provide:

• Stylesheets and javascript
• Translations
• Panels
• And we're in the process of allowing them to insert custom content in pre-defined places of the existing user interface, this is the subject of this document.

Writing a simple UI Extension

In this example we will write an extension for the Applications Panel UI Extension Point (ID: org.xwiki.platform.panels.Applications).

To create a UI Extension you need to:

Create a new document, for example Main.HelloWorldUIExtension

Switch to the object editor

Add a XWiki.UIExtensionClass object to it

Fill the information required by the extension point, you need to refer at the Extension Point (EP) documentation at this point.
In this example the extension point requires the following:

• Extension Point ID: in our example org.xwiki.platform.panels.Applications
• Extension Name: any name would be fine but we're following a rule for this EP "platform.panels." + the name of your extension, in our case "HelloWorld"
• Extension Content: the EP doesn't require any here
• Extension Parameters: here's the important part, the EP requires 3 parameters:
  • label: the label of the link that will be created
  • target: the target of the link that will be created, it must be a reference to a document
  • icon: the icon that will be put in the link, it must be a reference to an image, to look good this image must be 16 pixels in both height and width. 
• Extension Scope: defines where and for who your extension will appear: only in the current wiki (default value), globally (for a whole wiki farm) or only for the current user (ie. you, the user who wrote the extension)

Save the document

You can now see a new entry in the Applications Panel

Extension Points

Extension Points are "declared" or "created" through a call to the UIX api :

While they are easy to created you must remember that the Extension Point itself will be considered as an API. They must not be renamed or removed once they've been released.
Filters can be applied to the list of retrieved extensions, in order to exclude some of them for example. Filters are passed to the API through a Map :

The list of available filters is the following:

• exclude : takes a list of UI Extension IDs as parameter. Those extensions won't be retrieved.
• select : takes a list of UI Extension IDs as parameter. Only the listed extensions will be retrieved
• sortByCustomOrder : takes a list of UI Extension IDs as parameter. The extensions will be in the same order as they've been listed, additional extensions will be put at the end of the list.
• sortById : takes an empty string as parameter. The extensions will be ordered by their IDs, alphabetically.
• sortByParameter : takes a parameter key as parameter. The extensions will be ordered by the value of this parameter, alphabetically. If all the parameter values appear to be numbers they will be numerically ordered.

Available UI Extension Points

Here is the exhaustive list of UI Extension Points (EP) provided by the XWiki Platform.

Applications Panel

The Application Panel defines 2 EPs.

Extension Point: List of applications

This EP allows adding items in the Application Panel.

Extension Point ID

org.xwiki.platform.panels.Applications

Extension Name

The rule here is platform.panels.[nameOfYourApplication]Application, for example: platform.panels.blogApplication. This is important because extensions are ordered by name by this EP.

Content

not taken into account by the Extension Point

Parameters

Extension Point: More applications

This EP allows adding items in the Application Panel but those items are only visible when clicking the "More Applications" link.

Extension Point ID

org.xwiki.platform.panels.Applications.more

Extension Name

The extension name, for example platform.panels.newApplication. Extensions are ordered by name by this EP.

Content

not taken into account by the Extension Point

Parameters