Release status: beta
|Implementation||Link markup, Tag, Extended syntax|
|Description||Add bits of information to other subjects. This is mainly useful for large amounts of subjects with very little information about them|
In the ZIP download
|Check usage and version matrix|
What can this extension do? 
Semantic Annotations allows a subject (page) to provide information about other subjects.
An article can 'inject' information to other article pages. The syntax is
[[OtherPage!!Information about that page]]
The above line results in a separate box on OtherPage with the name of this page and the String after the '!!'. If the target page is not yet existing, it is created automatically. The current page will display the information (without page name). It is possible to provide an alternate text for the current page, using the vertical bar |. The alternate text may not contain semantic constructs. The annotation may contain newslines for readability - on the target page, the annotation is shown on a single line.
You can place about any Mediawiki formatting into an annotation. Some content is treated differently on sender and target page:
- Categories: If an annotation contains a category, the target page is put into that category, but /not/ the sending page.
- Semantic information: You can place semantic links according to the SMW syntax into an annotation. The semantics is only processed in the target page. For the sending page, the information is treated as a standard link.
Further, it is possible to nest annotations. We always consider the first page as being the sender of the annotation. (The user should see where the information is originating from.)
The page 'Story' contains:
Peter [[Peter!!is watching [[TV!!a good show]] ]]
Will result in the following output:
- Story: Peter is watching a good show
- Peter: "Annotations from Story: is watching a good show"
- TV: "Annotations from Story: a good show"
(the annotation is nested, but still sent by the containing page "Story")
If a page makes the same annotation to the same subject twice, it is stored and displayed only once.
Moving the sending page is supported. Its name is updated on all receiving pages. If the receiving page is moved, the annotations directed to the old page can not be transferred to the new page and thus become invisible. This is the same with semantic mediawiki.
Download instructions 
Download the zip file from http://davidbu.ch/mann/blog/2010-03-12/mediawiki-extensions.html and extract it into the extensions folder of your MediaWiki installation.
To install this extension, add the following to LocalSettings.php:
include_once("$IP/extensions/SemanticAnnotations/includes/SA_Settings.php"); enableAnnotations('<domain name of your wiki installation>');
Fix Typo: Edit extensions/SemanticAnnotations/includes/SA_Settings.php and add */ after the introduction (line 6)
You also need Extension:SemanticMediaWiki for this extension to work. Please include the SemanticAnnotations extension before including Semantic MediaWiki.
Then point your browser to the page Special:SAAdmin to complete the installation.
Semantic Annotations can be controlled by a couple of configuration options. See SA_Settings.php for available options.
See also 
The code concept for this extension is heavily inspired by Extension:SemanticMediaWiki. If you just want Mediawiki to automatically create pages referenced by Semantic Links, please see Extension:CreateVirtualPages.