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SemanticMediaWiki is a MediaWiki extension.

Status for Mediawiki4Intranet distribution:

  • Inclusion date: 2012-12-12
  • Included version: 2.3.x
  • Improvement status: Forked in MediaWiki4Intranet with major improvements

Usage note

It seems almost nobody uses SMW for its original ideas (semantic web, rdf, ontologies and etc) — everyone just uses it to be able to add properties to pages, create something like «object model», create Semantic Forms, use #ask queries as something like «sql» for objects and turn MediaWiki into a CMS.

But SMW is far from ideal for this purpose — it’s not that fast, properties are global (i.e. not specific to an object class), and the #ask query language is not so convenient… Usually it ends up with a massive amount of very ugly «Wiki-programming» efforts.

So, avoid massive usage of SMW if you can. If you still have to use it, check our improvements to it (see below).

Our improvements

  • Query optimizer: identical subqueries are executed only once (for example, in <q>a OR b</q> <q>c OR d <q>a OR b</q></q> the «a OR b» part will be executed only once), identical terms are removed from conjunctions/disjunctions («a AND a», «a OR a» == just «a»).
  • Negation operator support: syntax is {{#ask: [[prop::val]] !<q>...subquery...</q> }} or just {{#ask: [[prop::val]] ![[prop2::val2]] }}.
  • Permission hook support (allows to use SMW, for example, with IntraACL).
  • Fixed PostgreSQL support (may be merged into the next original release, 2.4).
  • Fixed localised boolean value names (yes/no).
  • Support for selection of property chains ({{#ask: ... | ?Prop1.Prop2}}) and sorting on them ({{#ask: ... | sort=Prop1.Prop2}}).
  • LEFT JOINs on sort fields — pages without sort property do not disappear from query results anymore.
  • Fixed fatal error when handling empty <info /> tag on wiki pages.
  • Support long titles (up to 767 bytes), like in our Mediawiki4Intranet core patch.
  • Bugfix for rebuildData.php: it didn’t accept --conf option.
  • Internal bugfix for ParserData which allows other extensions to retrieve page SemanticData before saving it.
  • Bugfix for count API requests.
  • Add predefined properties for major modification date (i.e. the timestamp of latest non-minor revision), major revision comment, last revision comment. All are optional and must be enabled in $smwgPageSpecialProperties to work.