function _flatten(&$result, $subject, $delimiter = '_', $prefix = '')
{
assertTrue(is_array($result) || is_object($result));
assertTrue(is_array($subject) || is_object($subject));
foreach ($subject as $key => $value) {
if (is_array($value) || is_object($value)) {
_flatten($result, $value, $delimiter, $prefix . ($prefix ? $delimiter : '') . $key);
} else {
if (is_array($result)) {
$result[$prefix . ($prefix ? $delimiter : '') . $key] = $value;
} else {
$result->{$prefix . ($prefix ? $delimiter : '') . $key} = $value;
}
}
}
}
/**
* Normalizes a JSON-LD object.
*
* @param input the JSON-LD object to normalize.
*
* @return the normalized JSON-LD object.
*/
public function normalize($input)
{
$rval = array();
// TODO: validate context
if ($input !== null) {
// expand input
$expanded = _expand(new stdClass(), null, $input, true);
// assign names to unnamed bnodes
$this->nameBlankNodes($expanded);
// flatten
$subjects = new stdClass();
_flatten(null, null, $expanded, $subjects);
// append subjects with sorted properties to array
foreach ($subjects as $key => $s) {
$sorted = new stdClass();
$keys = array_keys((array) $s);
sort($keys);
foreach ($keys as $i => $k) {
$sorted->{$k} = $s->{$k};
}
$rval[] = $sorted;
}
// canonicalize blank nodes
$this->canonicalizeBlankNodes($rval);
// sort output
usort($rval, '_compareIris');
}
return $rval;
}