/** Constructor for creating a new literal
*
* @param string $value The value of the literal
* @param string $lang The natural language of the literal or null (e.g. 'en')
* @param string $datatype The datatype of the literal or null (e.g. 'xsd:string')
*
* @return Literal
*/
public function __construct($value, $lang = null, $datatype = null)
{
$this->value = $value;
$this->lang = $lang ? $lang : null;
$this->datatype = $datatype ? $datatype : null;
if ($this->datatype) {
if (is_object($this->datatype)) {
// Convert objects to strings
$this->datatype = strval($this->datatype);
} else {
// Expand shortened URIs (CURIEs)
$this->datatype = RdfNamespace::expand($this->datatype);
}
// Literals can not have both a language and a datatype
$this->lang = null;
} else {
// Set the datatype based on the subclass
$class = get_class($this);
if (isset(self::$classMap[$class])) {
$this->datatype = self::$classMap[$class];
$this->lang = null;
}
}
if (is_float($this->value)) {
// special handling of floats, as they suffer from locale [mis]configuration
$this->value = rtrim(sprintf('%F', $this->value), '0');
} else {
// Cast value to string
settype($this->value, 'string');
}
}
/** Add one or more rdf:type properties to a resource
*
* @param string $resource The resource to add the type to
* @param string $types One or more types to add (e.g. foaf:Person)
*
* @return integer The number of types added
*/
public function addType($resource, $types)
{
$this->checkResourceParam($resource, true);
if (!is_array($types)) {
$types = array($types);
}
$count = 0;
foreach ($types as $type) {
$type = RdfNamespace::expand($type);
$count += $this->add($resource, 'rdf:type', array('type' => 'uri', 'value' => $type));
}
return $count;
}
/**
* Delete an existing RDF type mapping.
*
* @param string $type The RDF type (e.g. foaf:Person)
*
* @throws \InvalidArgumentException
*/
public static function delete($type)
{
if (!is_string($type) or $type == null or $type == '') {
throw new \InvalidArgumentException("\$type should be a string and cannot be null or empty");
}
$type = RdfNamespace::expand($type);
if (isset(self::$map[$type])) {
unset(self::$map[$type]);
}
}
