Semantic MediaWiki

Category:MediaWiki extension Semantic MediaWiki
Extension name	Semantic MediaWiki
About this article / disclaimer
Logo
Screenshot
Location of the main author	The following coordinate was not recognized: Geocoding failed.
Coordinates of the main authors	Geocoding failed
Developers	Markus Krötzsch, Denny Vrandecic, Jeroen De Dauw, others
Licences
Description	Semantic MediaWiki is an extension for managing structured data in your wiki and for querying that data to create dynamic representations: tables, timelines, maps, lists, etc.
Mediawiki requirements	Any recent version
Dependencies	none
Related extensions (documented here)	Semantic Forms, Semantic Drilldown, Semantic Result Formats
Related extensions
Discussion
Language support	PHP
Status	stable
First release date	2005/01/01
Last release date (as of 2013/06/26!)	2013/05/01
Last version number	1.8.0.5
Programming language	PHP
Alternatives
Website	home page
Publications
Support websites	web site
Example websites
Last edited	2013/06/26

This article or section is a stub. It does not yet contain enough information to be considered a real article. In other words, it is a short or insufficient piece of information and requires additions.

Draft

Introduction

“Semantic MediaWiki (SMW) is an extension of Mediawiki – the wiki application best known for powering Wikipedia – that helps to search, organise, tag, browse, evaluate, and share the wiki's content. While traditional wikis contain only text which computers can neither understand nor evaluate, SMW adds semantic annotations that allow a wiki to function as a collaborative database. Semantic MediaWiki was first released in 2005, and currently has over ten developers, and is in use on hundreds of sites. In addition, a large number of related extensions have been created that extend the ability to edit, display and browse through the data stored by SMW: the term "Semantic MediaWiki" is sometimes used to refer to this entire family of extensions. Semantic MediaWiki has been funded in part by projects of the Framework Programmes (FP) of the European Union, SEKT and ACTIVE and by project Halo.” (Introduction to Semantic MediaWiki, retrieved 14:31, 24 August 2011 (CEST))

According to Semantic MediaWiki, “is currently in active use in hundreds of sites, in many languages, around the world, including Fortune 500 companies, biomedical projects, government agencies and consumer directories”.

Principles

Properties

At the core of Semantic MediaWiki are so-called properties. Properties can be understood as "categories of information" and they are encoded in a way that a machine can understand.

For example, if we would like to add the information that Semantic MediaWiki is related to Semantic Forms, we could express by adding a formal property/value pair to this page.

This page (Semantic MediaWiki) is the object that we describe with a property
Is related would be a good property name
The Semantic Forms page is the value of the property.

[[Is related to::Semantic Forms]]

Similarities with RDF

In the Resource Description Framework RDF, a fragment like the following defines the same relationship.

<swivt:Subject rdf:about="http://edutechwiki.unige.ch/en/Special:URIResolver/Semantic_MediaWiki">
  <property:Is_related_to rdf:resource="http://edutechwiki.unige.ch/en/Special:URIResolver/Semantic_Forms"/>
</swivt:Subject>

In some ways, Semantic MediaWiki is the Wiki equivalent of RDF. Semantic data of a page can be exported as RDF like this:

[http://edutechwiki.unige.ch/en/Special:ExportRDF/Semantic_MediaWiki RDF feed], e.g. click on RDF feed

Syntax extensions for Semantic MediaWiki

Properties with values

Properties in a Semantic MediaWikis define typed data, in a similar way as in object-oriented programming. Properties are used with the [[property_name::property_value]] syntax. By default, the value of a property is a wiki page, i.e. default data type of a property is simply a wiki page.

MediaWiki [[is a:: Wiki]]

The following example has data of type URL

[[Has_website:: http://www.semantic-mediawiki.org/wiki/Semantic_MediaWiki]]

The above code will be shown as http://www.semantic-mediawiki.org/wiki/Semantic MediaWiki ,i.e. the reader will only see the value of the property.

We shall explain below, how to create properties.

Property types:

There exist several types, for example:

Page (a wiki page, this the value by default, i.e. if you don't define a data type a property will result in a "blue" or "red" link to a normal wiki page)
String (a short text)
Text (a longer text)
Code (same but pre-formatted)
URL (various kinds of URIs, including http://)
Number
Date
Enumeration (lists of values, i.e. of all the other types)
Boolean

Manual coding

Each property must be created as a page in the properties namespace. To create a property with aproperty_name and a value, just use the following syntax:

[[property_name:: your_property_value]]

You then can type the property. By default a property is of type page, i.e. it will link to a normal wiki page. For example [[is a:: Wiki]] will declare that this is a Wiki and then link to the page Wiki like this: Wiki

To define a property type there are two methods

(1) edit the property:your_property page and add a type declaration like this:

This is a property of type [[Has type::URL]].

(2) The easiest way to create a property (including its page and the type declaration) is to use the form in Special:CreateProperty "special" page.

Displaying properties

The way a property will be displayed depends on its type and an additional parameter.

The following shows like this. Note that the data type of has accronym is a simple text, therefore no wiki link (as per default data type):

[[has example code::<nowiki>[[has accronym:: SMW]]

[[has example code::[[has accronym:: SMW]] <nowiki>[[has example code::<nowiki>[[has accronym:: SMW| ]]

[[has example code::<nowiki>[[has accronym:: SMW]]

Annotated values

The Swiss Grading scale goes from 0 to [[grading scale:=6]]

Inline queries

Semantic Mediawiki includes a query language for semantic search. According to the manual (7/2013), it can be used in three contexts:

Through the form of the Special:Ask page,
in so-called concepts, i.e. saved queries,
and in inline queries.

Queries usually define three things:

Which page(s) to select. Read Selecting pages (semantic-mediawiki.org)
What information to display about those pages. Read Displaying information (semantic-mediawiki.org)
How the results should be formatted. Additional extensions like Semantic Result Formats add further possibilities.

Inline queries dynamically include query results as in the examples below. This functionality is implemented with so-called parser functions.

The #ask function takes a number of parameters, in particular: page selection, information to display, and how.
the #show function displays information for a single page, i.e. it's a kind of shortcut for the #ask function.

One simple query would list all pages in a category. The following code:

{{#ask: [[Category: MediaWiki extension]]}}

produces a simple line:

Maps (MediaWiki extension), Mediawiki collection extension installation, Page Forms, Semantic Drilldown, Semantic Forms Inputs, Semantic Maps, Semantic MediaWiki, Semantic Result Formats, VisualEditor

The following code selects all pages in the category software information that include a property value Yaron Koren for the property Is developed by.

{{#ask: [[Category: MediaWiki extension]] [[Is developed by::Yaron Koren]]
 | ?Has name
 | format=ul
}}

It will produce this:

Page Forms (Has name: Semantic Forms)
Semantic Drilldown (Has name: Semantic Drilldown)
Semantic Forms Inputs (Has name: Semantic Forms Inputs)
Semantic Result Formats (Has name: Semantic Result Formats)

By default, results that include properties are shown as a table. The following code selects the same pages as above, but also displays has last revision number values.

{{#ask: [[Category: MediaWiki extension]] [[Is developed by::Yaron Koren]]
 | ?Has name
 | ?has last revision number
}}

produces this:

	Has name	Has last revision number
Page Forms	Semantic Forms	2.6 (Dec 2013)
Semantic Drilldown	Semantic Drilldown	1.2.5 (June 2013)
Semantic Forms Inputs	Semantic Forms Inputs	0.7
Semantic Result Formats	Semantic Result Formats	1.9.1 alpha (9482833)

Read more in Inline queries, Displaying information and Result formats (Semantic-Mediawiki.org)