Extension:SemanticDependencyUpdater

MediaWiki extensions manual

Semantic Dependency Updater Release status: stable
Implementation	User interface
Description	Detects semantic inserts and deletions, including changes recorded on subobjects.
Author(s)	Simon Heimler, Alexander Gesinn
Maintainer(s)	gesinn.it
Latest version	5.0.0 (2026-02-03)
MediaWiki	1.43+
Database changes	No
Parameters $wgSDUProperty = 'Semantic Dependency'; $wgSDUUseJobQueue = false;
Hooks used SMW::SQLStore::AfterDataUpdateComplete
Licence	MIT License
Download	GitHub: project page git repository URL commit history Note: No localisation updates are provided by translatewiki.net . Releases
Compatibility Semantic MediaWiki 6+

The Semantic Dependency Updater (SDU) extension detects semantic inserts and deletions, including changes recorded on subobjects. If the "Semantic Dependency" property is found, this extension will update all pages that have been selected through that property. A common use case is change propagation, where pages need to update (pull) their semantic data via an ask query from a changed page.

The "Semantic Dependency property" is evaluated as an ASK query. It is therefore possible to define either a list of pages directly or do more complex selections.

It is possible to build a chain of semantic dependencies that will update recursively. Be careful not to build loops!

Installation

Semantic MediaWiki 4 or later is required!

• Download and place the file(s) in a directory called SemanticDependencyUpdater in your extensions/ folder.
• Add the following code at the bottom of your LocalSettings.php file:

  wfLoadExtension( 'SemanticDependencyUpdater' );
  

• Configure as required.
• Done – Navigate to Special:Version on your wiki to verify that the extension is successfully installed.

Instead of downloading the zip archive, you may also check this extension out via Git:

git clone https://github.com/gesinn-it/SemanticDependencyUpdater.git extensions/SemanticDependencyUpdater

Configuration

Mandatory

Make sure a "Semantic Dependency" property exists, e.g., "Property:Semantic_Dependency" needs to exist and MUST be of the datatype Text:

[[Has type::Text]]

Optional

// Name of the Semantic Dependency property
$wgSDUProperty = 'Semantic Dependency';

// If enabled, SDU will enqueue an UpdateJob for each dependent page.
// This is recommended for larger dependency graphs to avoid long save times.
$wgSDUUseJobQueue = true;

// If disabled, SDU will run a single forced update immediately after saving.
// This is useful for small setups or debugging, but may increase save latency.
$wgSDUUseJobQueue = false;

Usage

The value of the Semantic Dependency property is evaluated as an ASK query, except that [[ or ]] must be omitted. If there are more conditions, combine them through AND and OR

Examples

Update Self

This will save the current page twice. Useful when the page stores semantic properties that are calculated from other properties of the same page.

[[Semantic Dependency::{{FULLPAGENAME}}]]

Update other page(s)

[[Semantic Dependency::Product:Test Product]]
[[Semantic Dependency::{{{Target Page|}}}]]

Update pages with relation to current page

This will update all pages that link with Part Of to the current page.

[[Semantic Dependency::Part Of::{{FULLPAGENAME}}]]

More Advanced Queries

Be careful not to return too many pages, as this can cause a heavy load.

[[Semantic Dependency::Category:Product]]
[[Semantic Dependency::Category:Product AND Tag::Demo]]
[[Semantic Dependency::Category:Person OR Category:Organization]]

Example test case

• Make sure, a page Property:Semantic_Dependency exists with content [[Has type::Text]]
• Make sure the property Property:Title exists with the content [[Has type::Text]]
• Make sure, $wgSDUUseJobQueue = false;
• Create a page A with

[[Title::A]]
[[Semantic Dependency::Part Of::{{FULLPAGENAME}}]]

• Create a page B with

* [[Part Of::A| ]][[Title::{{#show:A|?Title}}.B]]
* {{#show:{{FULLPAGENAME}}|?Title}}

• Now, change page A as follows

[[Title::XXX]]
[[Semantic Dependency::Part Of::{{FULLPAGENAME}}]]

As a result, you should see

- XXX.B
- XXX.B

on page B

Debugging

• Note that on some systems, logging to /tmp might not work
• Make sure a log folder, writable by your web server, exists

> mkdir /var/log/mediawiki
> chown -R www-data /var/log/mediawiki

• In your LocalSettings.php enable

$wgDebugLogGroups['SemanticDependencyUpdater'] = '/var/log/mediawiki/SDU.log';

• Watch the log file

> tail -f /var/log/mediawiki/SDU.log

• If things work as expected, this will look like:

2020-03-25 13:01:45 vagrant wikidb01-wk: [SDU] --> A
2020-03-25 13:01:45 vagrant wikidb01-wk: [SDU] -----> Data changes detected
2020-03-25 13:01:45 vagrant wikidb01-wk: [SDU] --------> [[Part Of::A]]
2020-03-25 13:01:45 vagrant wikidb01-wk: [SDU] --------> [Edit] B