/** Add a literal value as a property of a resource
*
* The resource can either be a resource or the URI of a resource.
* The value can either be a single value or an array of values.
*
* Example:
* $graph->add("http://www.example.com", 'dc:title', 'Title of Page');
*
* @param mixed $resource The resource to add data to
* @param mixed $property The property name
* @param mixed $value The value or values for the property
* @param string $lang The language of the literal
*/
public function addLiteral($resource, $property, $value, $lang = null)
{
$this->checkResourceParam($resource);
$this->checkPropertyParam($property, $inverse);
if (is_array($value)) {
foreach ($value as $v) {
$this->addLiteral($resource, $property, $v, $lang);
}
return;
} else {
if ($lang) {
$value = array('type' => 'literal', 'value' => $value, 'lang' => $lang);
} else {
$value = array('type' => 'literal', 'value' => $value, 'datatype' => EasyRdf_Literal::getDatatypeForValue($value));
if (empty($value['datatype'])) {
unset($value['datatype']);
}
}
}
return $this->add($resource, $property, $value);
}
/** Check that a value parameter is valid, and convert it to an associative array if needed
* @ignore
*/
protected function checkValueParam(&$value)
{
if (isset($value)) {
if (is_object($value)) {
if (!method_exists($value, 'toRdfPhp')) {
// Convert to a literal object
$value = EasyRdf_Literal::create($value);
}
$value = $value->toRdfPhp();
} elseif (is_array($value)) {
if (!isset($value['type'])) {
throw new InvalidArgumentException("\$value is missing a 'type' key");
}
if (!isset($value['value'])) {
throw new InvalidArgumentException("\$value is missing a 'value' key");
}
// Fix ordering and remove unknown keys
$value = array('type' => strval($value['type']), 'value' => strval($value['value']), 'lang' => isset($value['lang']) ? strval($value['lang']) : null, 'datatype' => isset($value['datatype']) ? strval($value['datatype']) : null);
} else {
$value = array('type' => 'literal', 'value' => strval($value), 'datatype' => EasyRdf_Literal::getDatatypeForValue($value));
}
if (!in_array($value['type'], array('uri', 'bnode', 'literal'), true)) {
throw new InvalidArgumentException("\$value does not have a valid type (" . $value['type'] . ")");
}
if (empty($value['datatype'])) {
unset($value['datatype']);
}
if (empty($value['lang'])) {
unset($value['lang']);
}
if (isset($value['lang']) and isset($value['datatype'])) {
throw new InvalidArgumentException("\$value cannot have both and language and a datatype");
}
}
}
