/**
* Sorts an array of DOM nodes based on document position, in place, with the duplicates removed.
* Note that this only works on arrays of DOM nodes, not strings or numbers.
*
* @param \DOMNode[] $array array of DOM nodes
* @throws \InvalidArgumentException
* @return array
*/
public function unique(array $array)
{
$count = count($array);
if ($count <= 1) {
if ($count == 1) {
Constraints::assertNode(reset($array), 'Array must only contain dom nodes, found "%s".');
}
return $array;
}
$sortable = array();
$unsortable = array();
foreach ($array as $node) {
Constraints::assertNode($node, 'Array must only contain dom nodes, found "%s".');
$hash = spl_object_hash($node);
if ($node->parentNode instanceof \DOMNode || $node === $node->ownerDocument->documentElement) {
/* use the document position as index, ignore duplicates */
if (!isset($sortable[$hash])) {
$sortable[$hash] = $node;
}
} else {
/* use the object hash as index, ignore duplicates */
if (!isset($unsortable[$hash])) {
$unsortable[$hash] = $node;
}
}
}
uasort($sortable, new Nodes\Compare($this->xpath));
$result = array_values($sortable);
array_splice($result, count($result), 0, array_values($unsortable));
return $result;
}
