Init

First of all, you need a Client to build and execute your SPARQL queries.

require_once "./vendor/autoload.php";
use MadBob\Sparqler\Client;
$client = new Client($config);

where $config is an associative array with the following keys:

host (required): the SPARQL endpoint you want to query
graph (optional): the name of the graph you want to query. Useful if you want to interact with your own linked data store
auth (optional): an associative array with the authentication parameters you need to access the SPARQL endpoint. Required in particular if you want to interact with your own linked data store. If defined, it must contain the following keys:
- type: one of the authentication method supported by Guzzle: basic, digest or ntml
- username: your username
- password: your password
namespaces (optional): an associative array with the namespaces to be used in your queries. By default EasyRDF already defines the most common ones; if this parameter is defined, the new array overrides the default one
omit_prefix (optional): if set to true, the final queries will not include PREFIXes at the beginning

The internal HTTP client used to perform requests to the SPARQL endpoint can be accessed and configured as desidered. By default it is an instance of EasyRDF-on-Guzzle to integrate a full-featured Guzzle client (using a cURL handler) with EasyRDF, so you can consult the Guzzle documentation for more options.

$client = new Client($config);
$httpclient = \EasyRdf\Http::getDefaultHttpClient();
$httpclient->setConfig(['timeout' => 20]);

It is also possible to attach to the Client a PSR-3 LoggingInterface, where all generated queries are saved, and a PSR-16 CacheInterface, used only for inference functions.

$client = new Client($config);
$client->setLogger($your_LoggerInterface);
$client->setCache($your_CacheInterface);

A few sample inititialization for common use cases:

// Wikidata client
$client = new Client([
  'host' => 'https://query.wikidata.org/sparql',

  // For more namespaces used in Wikidata:
  // https://www.mediawiki.org/wiki/Wikibase/Indexing/RDF_Dump_Format#Full_list_of_prefixes
  'namespaces' => [
    'wd' => 'http://www.wikidata.org/entity/',
    'wdt' => 'http://www.wikidata.org/prop/direct/',
    'rdfs' => 'http://www.w3.org/2000/01/rdf-schema#',
  ],
]);

// DBPedia client
$client = new Client([
  'host' => 'https://dbpedia.org/sparql',

  // For more namespaces used in DBPedia:
  // https://dpedia.org/sparql/?help=nsdecl
  'namespaces' => [
    'dbp' => 'http://dbpedia.org/property/',
    'dbr' => 'http://dbpedia.org/resource/',
    'dbo' => 'http://dbpedia.org/ontology/',
    'dct' => 'http://purl.org/dc/terms/',
    'dbc' => 'http://dbpedia.org/resource/Category:',
    'rdf' => 'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
  ],
]);

// Your own Virtuoso server
$client = new Client([
  'host' => 'http://localhost:8890/sparql-auth',
  'graph' => 'urn:sparql:tests:insert:informative',
  'auth' => [
    'type' => 'digest',
    'username' => 'dba',
    'password' => 'your_password',
  ],
]);

// Your own Apache Jena server
$client = new Client([
  'host' => 'http://localhost:8080/your-dataset',
]);

From a Client instance, it is possible to obtain a Builder for each kind of query you want to perform.