Extension:Semantic Compound Queries

Semantic Compound Queries is an extension to MediaWiki, meant to work with Semantic MediaWiki, that allows for the display of more than one SMW inline query in one results display set. It uses its own parser function, #compound_query, that takes inputs similar to that of #ask but can take in an unlimited number of queries, instead of just one.

Semantic Compound Queries was funded initially by the KDZ - Centre for Public Administration Research in Vienna, Austria.

Download
You can download the Semantic Compound Queries code in either one of these two compressed files:


 * semantic_compound_queries_0.2.6.tar.gz
 * semantic_compound_queries_0.2.6.zip

You can also download the code directly via SVN from the MediaWiki source code repository, at http://svn.wikimedia.org/svnroot/mediawiki/trunk/extensions/SemanticCompoundQueries/. From a command line, you can call the following:


 * svn checkout http://svn.wikimedia.org/svnroot/mediawiki/trunk/extensions/SemanticCompoundQueries/

You can also view the code here.

Installation
To install this extension, create a 'SemanticCompoundQueries' directory (either by extracting a compressed file or downloading via SVN), and place this directory within the main MediaWiki 'extensions' directory. Then, in the file 'LocalSettings.php', somewhere below the inclusion of Semantic MediaWiki (both the main 'include_once' line and the 'enableSemantics' line), add the following line:

Author
Semantic Compound Queries was written by Yaron Koren, reachable at yaron57 -at- gmail.com. Important contributions were made by Jeroen De Dauw.

Version
Semantic Compound Queries is currently at version 0.2.6.

The version history is:
 * 0.1 - November 19, 2008 - Initial version
 * 0.2 - November 25, 2008 - Two defined classes moved to their own files; fix for semicolons contained within query filters
 * 0.2.1 - December 1, 2008 - Fix for map icons with MW 1.12 or earlier
 * 0.2.2 - June 4, 2009 - Added internationalization, for extension description
 * 0.2.3 - October 13, 2009 - Added support for SMW 1.5; removed support for MW 1.11 and earlier
 * 0.2.4 - March 11, 2010 - Fix for extra whitespace in queries; duplication of values removed for SMW 1.5
 * 0.2.5 - May 13, 2010 - Fix for handling of query format aliases
 * 0.2.6 - September 23, 2010 - Improvements to PHP syntax; minor fix for SMW < 1.5

Usage
A normal inline query, using the #ask parser function, takes in arguments of three types: (1) a filter that determines the results, (2) the names of properties to be displayed, and (3) arguments that determine the format and other aspects of the display. Here is an example of a normal inline query:

In this query there are three arguments separated by pipes and they belong to argument types 1, 2 and 3, respectively.

For compound queries the first two types of argument are unique to each sub-query and are separated from each other by semicolons instead of pipes; pipes are used to separate one sub-query from the rest. The third type of argument, setting the display of the results, is common across all sub-queries. Here is an example of a call to #compound_query that shows both clothing stores and fast-food restaurants in a table:

To make things more interesting, we can place all these results on a map, using the Semantic Maps extension. Here is the same set of results, using SM's 'googlemaps' format, and a different property displayed for both sets of points to set their geographical coordinates:

We can set a different icon to appear for each location type in the map, by using the "icon" parameter, which Semantic Maps understands (note that this feature only works with MediaWiki 1.13 or higher). Assuming your wiki contains uploaded images by the name of "Shirt.png" and "Hamburger.png", you could call the following:

This query also sets the height and width of the map - additional arguments of the third type.


 * 1) compound_query avoids displaying the same page more than once, so if a page gets returned by more than sub-query, it's displayed only for the first one. In this way, a compound query can have specific sub-queries, and then a general catch-all sub-query at the end:

There's also special handling for the 'calendar' format, defined in Semantic Result Formats - if you display a calendar, you can set a different color for each set of events displayed. Here is an example:



Bugs and feature requests
You should use the Semantic MediaWiki mailing list, semediawiki-user, for any questions, suggestions or bug reports about Semantic Compound Queries. If possible, please add "[SCQ]" at the beginning of the subject line, to clarify the subject matter.

You can also send specific code patches to Yaron Koren, at yaron57 -at- gmail.com.