Some tips and tricks for using Semantic Mediawiki from SMW mailing list, various web sites, etc.
Workshops, tutorials, etc
- Semantic Mediawiki workshop
- Encouraging SMW use with non technical people
- Semantic Mediawiki compared with Drupal and content management systems
- information modelling
Other tip sources
- Create a top category for Semantic Classes. I called mine 'Categories'. It holds only categories used to define a 'Is-a' relationship. Doing so has at least two benefits : 1- You can do a query on your core content by restricting it to the 'Categories' level. 2- You can define other categories outside of that structure for whatever your system needs.
Redirects can be used to create property synonyms.
Categories can be hierarchical; properties can't (yet) - actually they can be, using subproperty of.
When to use categories vs properties?
If you want to clear out old pages you can delete them and use deleteArchivedRevisions.php to erase the deleted revisions from the database.
You can make use of the VariablesExtension  and store the query (or its result? I'd like to know which one, but in the end it doesn't really matter) in a variable, which is helpful when you need the same query multiple times within a page. It looks like this:
Further down in the page you can write
<nowiki> <inputbox> type=search width=30 namespaces=Help**,Wikipedia**,Template** searchbuttonlabel=Search help pages bgcolor=#cee0f2 break=no </inputbox> </nowiki>
(requires the Input Box extension)
Semantic Mediawiki performance
20,000 pages, 132,00 property values for 60 properties
Mediawiki performance tuning
- APC can be used with SMW without problems
<nowiki>Expression error: Unexpected > operator.warning.png"<strong class="error">Expression error: Unexpected > operator.</strong>" cannot be used as a page name in this wiki.</nowiki>
if you want to query an SMW installation from remote and re-use the results in other applications, I recommend checking out our Triplestore Connector. It delivers the results as XML format (compliant with the SPARQL recommendation).
If you want to query semantic data in your wiki, coming from another SMW installation you should take a further look at the Exhibit result printer.
Hiding set data
By adding the | after the enclosing }}}, the property value will not show.
For multi value properties:
(why not just use #set?)
Protecting #ask results
(from Markus Kr?tzsch)
- make a new property "has checked" of type page,
- make and a new page "main page news editor" (or whatever) and protect this page just like your main page,
- add an entry <nowiki>some page</nowiki> on "main page news editor" for every page that the editor has found to be okay to make it on the main page news feed,
- extend your #ask query on the main page with the condition <nowiki>main page news editorwarning.pngValues cannot be assigned to inverse properties.</nowiki>.
... Note that you can also have a group of editors with separate (protected) pages. You can also work with categories of editors for different topics etc. Of course, this is no longer a spam protection since categories are not protected either, but you can use another level of "has checked" to have a master editor who checks other editors to grant them trust. All of this readily works with subqueries+inverses. Applying similar methods but without actually protecting any pages maybe still be useful for managing feeds together in cases where spam is not a major issue.
$smwgLinksInValues = true;
Must add namespaces to config
Otherwise they won't have semantic properties.
$smwgLinksInValues = true;
Dark background theme css
Multi language SMW
Here's how I do it: As I have said many times before, I routinely declare all properties. And every declaration that is implemented in both languages, has the language-specific Interwiki prefix added, so that you can follow a property declaration from one language to the other and back.
All that is involved is making parallel property declarations and placing Interwiki language links in each one.
In general: a multilingual wiki is actually a family of wikis, each set up in its own language.
The important part is to make sure that the SMW language files exist in each language in which you are planning to implement SMW. Right now the language support is a little thin, in comparison to the incredible multiplicity of languages on Wikipedia. So those of you who are trying to persuade Wikipedia to implement SMW across their project will have an immediate problem: you don't support more than a handful of the languages they use.
... anyone who implements SMW in an unsupported language is going to have to write a language file. And make sure that his language is supported in SMW_Aliases.php and SMW_Messages.php.
'HKp wiki' is a bilingual (potentially multilingual) spanish-catalan wiki in the same installation. http://enlloc.net/hkp/w
I'm using Polyglot extension  to redirect to appropriate language pages depending on the browser language settings or the user wiki settings.
I'm using Language Selector extension for providing a language selector for every page in the sidebar.
I wanted to use the Multilang extension for changing the language in pages and forms depending on the user settings. But unfortunately this extension don't work in MW higher of 1.10.
Alternatively I'm using the <nowiki>Template:Internationalnowiki> template. It is useful for pages and templates but not for forms because it need a <nowiki>SMW notes</nowiki> with language code (/ca, /es, /en, /fr, /pt, ...).
I'm using my own code in templates to show or hide a "translation button" depending if the translation page exist or not:
Right now I have not solution for having only one form for all languages. What is annoying.
Neat talk on MW, with refs to SMW: http://www.youtube.com/watch?v=Ukytqe9pwDM