Searching for assets on the RES platform

get-assets.php

<?php
/**
 * Find assets associated to a particular topic
 *
 * In this example we search for all the assets related to a particular topic.
 * This topic has to be identified by its URI. In order to find the relevant
 * URI a first call to a search (see "search.php") can be necessary.
 * 
 * @copyright  Copyright (c) 2016 BBC
 * @license    http://unlicense.org/
 */

# Do some init to include EasyRDF and define useful namespaces
require_once realpath(__DIR__)."/vendor/autoload.php";
EasyRdf_Namespace::set('olo', 'http://purl.org/ontology/olo/core#');

# This is the identifier for the play "Romeo and Juliet"
$topic = "http://acropolis.org.uk/af28bd78a968460c9bba91839359539e#id";

# Load the description of the topic
$graph = EasyRdf_Graph::newAndLoad(str_replace('#id', '.rdf', $topic));

# Convert the ordered list of results into an array
$results = array();
foreach($graph->allOfType('olo:Slot') as $entry) {
	$index = $entry->get('olo:index')->getValue();
	$item = array();
	$item['uri'] = $entry->get('olo:item')->getUri();
	$results[$index] = $item;
}
ksort($results);

# Iterate over all the results to fetch additional information
foreach($results as $index => $item) {
	$graph->load(str_replace('#id', '.rdf', $item['uri']));
	foreach($graph->properties($item['uri']) as $property) {
		$item[$property] = array();
		foreach($graph->all($item['uri'], $property) as $value) {
			if (is_a($value, "EasyRdf_Literal"))
				array_push($item[$property], $value->getValue());
			else if (is_a($value, "EasyRdf_Resource"))
				array_push($item[$property], $value->getUri());
		}
	}
	$results[$index] = $item;
}

# Print all the results
print_r ($results);
?>