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Concepts

Abstract

Summary
A concept is a Semantic MediaWiki page in the Concept: namespace that serve as a category by dynamically linking pages to it, iff such pages satisfy the conditions defined as #ask query on the concept page.

Motivation

Problem

  • Sometimes, it is useful to determine memberships to categories based on the occurrence of some specific property values.
  • Reviewing whether membership conditions are still satisfied and manually altering categories is cumbersome and error-prone

Use Case

  • Automatically annotate all currently running projects with a dedicated category based on the evaluation of start and end date

Definition

Warning

Definition: « Concept »
Concepts are pages in the Concept: namespace and allow to dynamically compute page memberships based on the evaluation of query conditions defined on the concept page.

Quelle: Eigene Definition angelehnt an https://www.semantic-mediawiki.org/wiki/Help:Concepts

Function

Concepts
… are pages defined in the Concept: namespace
… serve as categories with individually evaluated memberships
… are declared using the #concept parser function
… dynamically link pages to categories based on formulated query conditions
… conditions are specified in the form of an #ask query
… results of the #ask query automatically become members of the concept
… can be browsed to view the contents of some concept – similar to category pages
… can be used in semantic queries just like categories
… are very useful in Page Forms for defining autocompletion values
Additional Remarks:
Concept pages can have additional content (e.g. wikitext) – but this text does not have any effect on the definition of the concept.
The #concept parser function can only be used on pages in the Concept: namespace

Syntax

Example

Example

Example
Using the concept named Semantic MediaWiki Cons 2012 in an #ask query to display the location of all SMW conferences held in 2012:

Syntax 

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{{#ask:
[[Concept:Semantic MediaWiki Cons 2012]]
|?Has location=Location 
|format=table
|headers=plain 
|mainlabel=Event
}}

Result

Event Location
SMWCon Fall 2012 Cologne, Germany
SMWCon Spring 2012 Carlsbad, CA, USA

Example

Example
Instead of annotating all currently running projects with a specific category (that certainly will be invalid for some projects after a certain amount of time), we can define a dynamic category in form of a concept.

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{{#concept:
[[Category:Project]]
[[Has planned start::< {{CURRENTYEAR}}-{{CURRENTMONTH}}-{{CURRENTDAY2}}]]
[[Has planned finish::> {{CURRENTYEAR}}-{{CURRENTMONTH}}-{{CURRENTDAY2}}]]
|All currently running projects
}}
Letztes Update: 18. September 2024