Ultrapedia-API Plugin for MediaWiki
===================================
Author: Christian Becker <chris@beckr.org>

This plugin extends the MediaWiki editing process to allow highlighting, as well as an update notification to a DBpedia endpoint.
It thereby implements functionalities 4.10.2.1 Wikipedia, Article Edit Form and 4.10.2.2, DBpedia Article Extraction as specified in the Ultrapedia Prototype I Design Phase Report.

Requirements
============
MediaWiki: This plugin was developed and tested against MediaWiki 1.15.1.
Browsers: Developed and tested against Internet Explorer 6, 7, 8; Firefox 3 (Mac/Windows), Safari 4 (Mac)

When using Firefox 2, the highlighted portion does not scroll with the text content. This is due to a known browser bug, see https://bugzilla.mozilla.org/show_bug.cgi?id=35011#c105.

Installation
============
The plug-in must be extracted into the extensions/ folder of a MediaWiki installation.
It is then included by adding the following lines at the bottom of MediaWiki's LocalSettings.php:

	define("ULTRAPEDIA_DBPEDIA_ENDPOINT", "http://wiking.vulcan.com/dbpedia/extractPage.php");
	require_once("$IP/extensions/Ultrapedia-API/Ultrapedia-API.php");

ULTRAPEDIA_DBPEDIA_ENDPOINT hereby specifies the URL of the DBpedia endpoint that is to receive the update notification.

Patches
=======
The functionality of the Ultrapedia-API plugin is enhanced through two minor patches to MediaWiki 1.15.1.
It is highly recommended to apply these patches for correct operation within the Ultrapedia Prototype I, although
the patches are technically not a dependency as they only concern error handling.

Article.php.1.15.1.patch: 

	This patch adds support for a new hook, RevisionSave, which is invoked after a revision has been saved,
	and can revert the revision by returning false.
	This allows the Ultrapedia-API plugin to obtain a revision ID for any updates while still being able to revert them
	in case they are rejected by the upstream systems.
	If the patch is not applied, the Ultrapedia-API plugin will fall back to using the ArticleSave hook, which
	does not possess revision information as it is invoked before the revision is created.

EditPage.php.1.15.1.patch: 

	MediaWiki 1.15.1 silently fails if a newly created article cannot be saved, contrarily to its handling when an article is updated.
	Because the Ultrapedia-API plugin actively prevents the saving of an article if the update can not be forwarded to DBpedia
	in order to maintain concurrency, this may confuse users and lead to lost edits.
	
	The patch provided in EditPage.php.1.15.1.patch fixes the issue by adding a new status code AS_ARTICLE_INSERT_FAILED to EditPage.php,
	along with appropriate handling. It is, however, not a manditory dependency of this plugin.
	
	To apply the patch using GNU patch, enter the following command from within the Ultrapedia-API extension directory:
	
	This patches EditPage.php and backs up the original file as EditPage.php.orig.
	
Applying the patches:

	To apply the patches using GNU patch, enter the following command from within the Ultrapedia-API extension directory:
	
		patch -b ../../includes/Article.php < patches/Article.php.1.15.1.patch
		patch -b ../../includes/EditPage.php < patches/EditPage.php.1.15.1.patch
	
	This patches Article.php and EditPage.php, backing up the original files as Article.php.orig and EditPage.php.orig.