Difference between revisions of "Semantic Mediawiki"

Latest revision as of 21:25, 13 November 2017

What is Semantic MediaWiki?

Semantic MediaWiki (SemanticMW) allows you to introduce some database functions into a wiki. For example you might have in a wiki the category countries with pages on different countries. With SemanticMW you can then define keywords for each country like what is the name of its capital and the name of its highest mountain, as well as numbers like the total land area, population size and height of its highest mountain. In a different page, say one called "Mountains", you could then use SemanticMW to generate automatically a table of all countries in which the countries are sorted by the height of their highest mountain and which then contains apart from the names of the countries information like the names of their highest mountain, the total land area of each country as well as other information as appropriate. While the mountains are fixed, populations change continuously. With SemanticMW the content of a table showing the population size of different countries will change automatically once you change the population size in the page for one particular country.

You will find a detailed description of - and a manual for SemanticMW at the SemanticMW website

Installation and maintenance

You need to have administrator rights to install SemanticMW. The steps are:

• Ensure the extension SemanticMediaWiki is enabled as described in Mediawiki installation. This is usually already the case.
• Add the following 2 lines to the end of the LocalSettings.php file for your wiki (e.g. examplewiki="biowikifarm.net/test"):

include_once("$IP/extensions/SemanticMediaWiki/includes/SMW_Settings.php");
// enableSemantics( parse_url( $wgServer, PHP_URL_HOST ) ); # or
enableSemantics('examplewiki.net');

• Log in at your wiki as an administrator and call up the page "Special:SMWAdmin"
• Click on "Initialise or upgrade tables". This will create the necessary tables and set up the SemanticMW.
• Click on "Start updating data". This will start an automatic process of adjusting the data in the wiki so that they can be used by SemanticMW. The process typically lasts several days. You can monitor its progress by calling up "Special:SMWAdmin".

For repairing and refreshing SemanticMW data see the corresponding section under Mediawiki maintenance.

Database access rights

The maintenance script needs MySQL DROP command to function otherwise the error will appear:

DROP command denied to user 'wikiuser'@'localhost' for table 'smw_new'

Check it in phpMyAdmin privileges settings tab. See also in Manual:Installing MediaWiki that the following MySQL commands can be used for 'wikiuser'

INDEX, CREATE, SELECT, INSERT, UPDATE, DELETE, ALTER, LOCK tables (14.12.2013)

Guidelines and examples

See Help:SemanticMW.

Complementary SemanticMW extensions

A variety of additional extensions exist which extend the functions of SemanticMW. The following table provides an overview of the more important ones and where they have been installed on the biowikifarm:

Interesting presentation from 2008: http://kontext.fraunhofer.de/haenelt/kurs/folien/Haenelt_SemWikiModelling.pdf