public function replaceElement(Element $oldElement, Element $newElement)
{
$body = str_replace($oldElement->getPlaceholder(), $newElement->getPlaceholder(), $this->body, $count);
if ($count === 0) {
throw new QtiModelException('cannot find the element to be replaced');
} else {
if ($count > 1) {
throw new QtiModelException('multiple placeholder found for the element to be replaced');
}
}
$this->removeElement($oldElement);
$this->setElement($newElement, $body);
}
protected function replaceNode(DOMElement $node, Element $element)
{
$placeholder = $this->data->createTextNode($element->getPlaceholder());
$node->parentNode->replaceChild($placeholder, $node);
}