rdf2json.php

<?
include_once('namespaces.php');
function uri2curie($uri){
	global $ns;
	$curie = $uri;
	foreach($ns as $k => $v){
		$curie = preg_replace("|^$v|", "$k:", $uri);
		if($curie != $uri){
		 break;
	 }
 }
 return $curie;
}

$results = array();
if(isset($_GET['url'])){
	$u = $_GET['url'];
	include_once('arc2/ARC2.php');

	//Because ARC2 doesn't seem to identify turtle docs using chinese characters
	//this is a workaround while its being fixed in ARC2


	$ch = curl_init();
	curl_setopt($ch, CURLOPT_URL, $u);
	curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
	curl_setopt($ch, CURLOPT_MAXREDIRS, 10);
	curl_setopt($ch, CURLOPT_HTTPHEADER,array ("Accept: text/turtle, text/n3; q=0.9, application/turtle; q=0.8, application/n-triples; q=0.7, application/rdf+xml; q=0.6, application/json; q=0.4, */*; q=0.1"));
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
	$data = curl_exec($ch);
	$_aux = curl_getinfo($ch, CURLINFO_CONTENT_TYPE);
	$_aux2 = explode(";", $_aux);
	$content_type = array_shift($_aux2);
	curl_close($ch);
	$parser = NULL;

	$parsers = array();
	$parsers[0]['formats'] = array('text/n3', 'application/x-turtle', 'application/turtle', 'text/turtle');
	$parsers[0]['parser']  = ARC2::getTurtleParser();
	$parsers[1]['formats'] = array('application/rdf+xml');
	$parsers[1]['parser']  = ARC2::getRDFXMLParser();
	$parsers[2]['formats'] = array('application/json', 'application/x-javascript', 'text/javascript', 'text/x-javascript', 'text/x-json');
	$parsers[2]['parser']  = ARC2::getJSONParser();
	foreach($parsers as $v){
		if(in_array($content_type, $v['formats'])){
			$parser = $v['parser'];
		}
	}
	//If nothing fits, pray to your favorite god that this can be detected and parsed correctly by ARC2.
	$parser = ARC2::getRDFParser();

	//end of workaround
	$parser->parse($u, $data); //Since IDK which namespace the documents contains, lets use the uri requested
	$triples = $parser->getTriples();
	$first=true;
	$c = 0;
	$nodes = array();
	$literals = array();
	$preds = array();
	$results['nodes'] = array();
	foreach($triples as $t){
		$s = uri2curie($t['s']);
		if(!isset($nodes[$t['s']])){
		 $nodes[$t['s']] = $c++;
		 $results['nodes'][] = array("name" => $s, "uri" => $t['s'], "type" => $t['s_type']);
		}
		if($t['o_type'] == 'literal'){
			$literals[$s][] = array("p" => uri2curie($t['p']), "o" => $t['o'], "l" => $t['o_lang'], "d" => $t['o_datatype']);
		}else{
			if(!isset($nodes[$t['o']])){
				$nodes[$t['o']] = $c++;
				$results['nodes'][] = array("name" => uri2curie($t['o']), "uri" => $t['o'], "type" => $t['o_type']);
			}
			if(!isset($preds[uri2curie($t['s'])." ".uri2curie($t['o'])])){
				$preds[uri2curie($t['s'])." ".uri2curie($t['o'])] = uri2curie($t['p']);
			}else{
				$preds[uri2curie($t['s'])." ".uri2curie($t['o'])] .= " ".uri2curie($t['p']);
			}
		}
	}
 $results['links'] = array();
foreach($triples as $t){
//    if(uri2curie($t['p']) !=  "rdf:type"){
	if($t['o_type'] == 'literal'){
			continue;
		}
 $results['links'][] = array("source" => $nodes[$t['s']], "target" => $nodes[$t['o']], "name" => $preds[uri2curie($t['s'])." ".uri2curie($t['o'])], "value" => 10);
//    }
}
$results['literals'] = $literals;
echo json_encode($results);
}else{
	header("HTTP/1.0 405 Method not allowed");
	echo "Please provide a url using the 'url' parameter\n\n";
}

?>