%META:TOPICPARENT{name="VirtDeployMediaWiki"}%
---+Installing The <nowiki>LinkedWiki v1.0.1.2 Extension</nowiki>

The LinkedWiki extension allows you to embed a SPARQL query and display the results in your wiki page.

---++Prerequisites

   * A working copy of <nowiki>MediaWiki</nowiki> hosted on Virtuoso.  (See [[http://wiki.usnet.private/dataspace/dav/wiki/Main/MediaWikiInstalltionGuide][the installation guide for MediaWiki on Virtuoso]]).  The <nowiki>MediaWiki </nowiki> VAD should be version 1.18.1.22 or higher.
   * The Semantic <nowiki>MediaWiki</nowiki> extension.  (See [[http://wiki.usnet.private/dataspace/dav/wiki/Main/SemanticMWVirtuoso][the installation guide for Semantic MediaWiki on Virtuoso]]).

---+++Step 1. Download the Extension.

Go to the [[http://www.mediawiki.org/wiki/Extension:LinkedWiki][LinkedWik Extension page]].  Using the links in the box on the right hand side, download the v1.0.1.2 LinkedWiki extension.

---+++Step 2. Extract.

Move the downloaded zip file into your <nowiki>MediaWiki</nowiki> extensions folder.  You will find this folder in <i>your Virtuoso installation directory</i>/vsp/vad/vsp/MediaWiki/extension.  Extract the extension.

---+++Step 3. Enable and Configure.

The LinkedWiki extension is enabled by adding the following lines to the <i>your Virtuoso installation directory</i>/vsp/vad/vsp/MediaWiki/LocalSettings.php file:
<verbatim>
require_once(  $IP."/extensions/LinkedWiki/lib/4store/SparqlTools.php");
require_once( "{$IP}/extensions/LinkedWiki/LinkedWiki.php" );
$smwgDefaultStore = "SMW_LinkedWikiStore"; 
$wgLinkedWikiGraphWiki = 'http://example.org/mydefaultgraphname'; 
</verbatim>

The extension is further configured by setting the endpoint and the SPARQL endpoint.  These will be the same as are used by Semantic <nowiki>MediaWiki</nowiki> and may be something like:
<verbatim>
$wgLinkedWikiEndPoint = "http://localhost:8890/";
$wgLinkedWikiLocalEndPoint = "http://localhost:8890/sparql/";
</verbatim>

---++Note
With this LinkedWiki extension errors are reported every time a page is saved. The message refers to missing functions on a Semantic <nowiki>MediaWiki</nowiki> class and seems to be due to this version of LinkedWiki being developed to use an earlier version of Semantic <nowiki>MediaWiki</nowiki> than the one that is bundled in the Virtuoso <nowiki>MediaWiki</nowiki> VAD.  The error does not in fact stop the page being saved.

---++Using LinkedWiki
LinkedWiki lets you embed a SPARQL query in a wiki page and display the results as a table.  

---+++Simple Query Examples
A simple query to get all the triples in all the graphs on the default endpoint:
<verbatim>
{{#sparql:select * where { ?x ?y ?z . } LIMIT 5}}
</verbatim>
This displays the first 5 triples. The results will look something like this:


   * <img src="%ATTACHURLPATH%/result1.png" style="wikiautogen"/>