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diff --git a/www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/README.md b/www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/README.md new file mode 100644 index 00000000..ec7da3d0 --- /dev/null +++ b/www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/README.md @@ -0,0 +1,101 @@ +# SPARQLStore + +The `SPARQLStore` is the name for the component that can establish a connection between a [RDF triple store][tdb] and Semantic MediaWiki (a more general introduction can be found [here](https://www.semantic-mediawiki.org/wiki/Help:Using SPARQL and RDF stores)). + +The `SPARQLStore` is composed of a base store (by default using the existing `SQLStore`), a `QueryEngine`, and a connector to the RDF back-end. Currently, the base store takes the position of accumulating information about properties, value annotations, and statistics. + +## Overview + +``` + SPARQLStore + |- SPARQLStoreFactory + |- ConnectionManager + | |- RepositoryConnectionProvider + | |- RepositoryClient + | |- RepositoryConnection + | |- FourstoreRepositoryConnector + | |- FusekiRepositoryConnector + | |- GenericRepositoryConnector + | |- VirtuosoRepositoryConnector + |- TurtleTriplesBuilder + |- RepositoryRedirectLookup + |- ReplicationDataTruncator + |- QueryEngine + |- HttpResponseParser + |- XmlResponseParser + |- ConditionBuilder + |- DescriptionInterpreter +``` + +## Repository connector + +A repository connector is responsible for establishing a communication between Semantic MediaWiki and an external [TDB][tdb] with the main objective to transfer/update triples from SMW to the back-end and to return result matches for a query request. + +The following client repositories have been tested: + +- [Jena Fuseki][fuseki] +- [Virtuoso][virtuoso] +- [Blazegraph][blazegraph] +- [Sesame][sesame] +- [4Store][4store] + +### Create a connection +<pre> +$connectionManager = new ConnectionManager(); + +$connectionManager->registerConnectionProvider( + 'sparql', + new RepositoryConnectionProvider( 'fuseki' ) +); + +$connection = $connectionManager->getConnection( 'sparql' ) +</pre> + +## QueryEngine + +The `QueryEngine` is responsible for transforming an `#ask` description object into a qualified +[`SPARQL` query][sparql-query] expression. + +- The `ConditionBuilder` builds a SPARQL condition from an `#ask` query artefact (aka [`Description`][ask query] object) +- The condition is transformed into a qualified `SPARQL` statement for which the [repository connector][connector] is making a http request to the back-end while awaiting an expected list of subjects that matched the condition in form of a `XML` or `JSON` response +- The raw results are being parsed by a `HttpResponseParser` to provide a unified `RepositoryResult` object +- During the final step, the `QueryResultFactory` converts the `RepositoryResult` into a SMW specific `QueryResult` object which will fetch the remaining data (those selected as printrequests) from the base store and make them available to a [`QueryResultPrinter`][resultprinter] + +### Create a query request +<pre> +/** + * Equivalent to [[Foo::+]] + * + * SELECT DISTINCT ?result WHERE { + * ?result swivt:wikiPageSortKey ?resultsk . + * ?result property:Foo ?v1 . + * } + * ORDER BY ASC(?resultsk) + */ +$description = new SomeProperty( + new DIProperty( 'Foo' ), + new ThingDescription() +); + +$query = new Query( $description ); + +$sparqlStoreFactory = new SPARQLStoreFactory( + new SPARQLStore() +); + +$queryEngine = $sparqlStoreFactory->newMasterQueryEngine(); +$queryResult = $queryEngine->getQueryResult( $query ); +</pre> + +[fuseki]: https://jena.apache.org/ +[fuseki-dataset]: https://jena.apache.org/documentation/tdb/dynamic_datasets.html +[sparql-query]:http://www.w3.org/TR/sparql11-query/ +[sparql-dataset]: https://www.w3.org/TR/sparql11-query/#specifyingDataset +[virtuoso]: https://github.com/openlink/virtuoso-opensource +[4store]: https://github.com/garlik/4store +[tdb]: http://en.wikipedia.org/wiki/Triplestore +[sesame]: http://rdf4j.org/ +[blazegraph]: https://wiki.blazegraph.com/wiki/index.php/Main_Page +[ask query]: https://www.semantic-mediawiki.org/wiki/Query_language +[connector]: https://www.semantic-mediawiki.org/wiki/Help:SPARQLStore/RepositoryConnector +[resultprinter]: https://www.semantic-mediawiki.org/wiki/Help:SPARQLStore/RepositoryConnector |