/**
* Get an Instance of OperationManufacturer
*
* @return ilAssLacOperationManufacturer
*/
public static function _getInstance()
{
if (self::$instance == null) {
self::$instance = new ilAssLacOperationManufacturer();
}
return self::$instance;
}
/**
* @param array $nodes
*
* @return array
*/
public function create($nodes)
{
if ($nodes['type'] == 'group') {
foreach ($nodes['nodes'] as $key => $child) {
$nodes['nodes'][$key] = $this->create($child);
}
foreach ($this->operators as $next_operator) {
do {
$index = -1;
for ($i = 0; $i < count($nodes['nodes']); $i++) {
if (!is_object($nodes['nodes'][$i]) && $nodes['nodes'][$i]['type'] == 'operator' && $nodes['nodes'][$i]['value'] == $next_operator) {
$index = $i;
break;
}
}
if ($index >= 0) {
$operation_manufacture = ilAssLacOperationManufacturer::_getInstance();
$operator = $operation_manufacture->manufacture($nodes['nodes'][$index]['value']);
$operator->setNegated($nodes["negated"]);
$operator->addNode($this->getExpression($nodes, $index - 1));
$operator->addNode($this->getExpression($nodes, $index + 1));
$new_nodes = array_slice($nodes['nodes'], 0, $index - 1);
$new_nodes[] = $operator;
$nodes['nodes'] = array_merge($new_nodes, array_slice($nodes['nodes'], $index + 2));
}
} while ($index >= 0);
}
return $nodes['nodes'][0];
}
return $nodes;
}
/**
* Cannonicalize the condition into a more general form. <br />
* It replaces all expression with "n" and all orperators with "o" <br />
* so that the result of an condition after cannonicalization could be:<br />
* <br />
* (n o n) o (n o n) o n
*/
protected function cannonicalizeCondition()
{
$manufacturer = ilAssLacExpressionManufacturer::_getInstance();
$this->condition = preg_replace($manufacturer->getPattern(), 'n', $this->condition);
$manufacturer = ilAssLacOperationManufacturer::_getInstance();
$this->condition = preg_replace($manufacturer->getPattern(), 'o', $this->condition);
$this->condition = preg_replace("/no/", "n o", $this->condition);
$this->condition = preg_replace("/on/", "o n", $this->condition);
for ($i = 0; $i < strlen($this->condition); $i++) {
if ($this->condition[$i] == "!" && !$this->isNegationSurroundedByBrackets($i)) {
$this->surroundNegationExpression($i);
}
}
}
