/**
* Traverse this node, updating the results array that is used by
* {@link stack_potentialresponse_tree::evaluate_response()}.
*
* @param stack_potentialresponse_tree_state $results to be updated.
* @param int $key the index of this node.
* @param stack_cas_session $cascontext the CAS context that holds all the relevant variables.
* @param stack_options $options
* @return array with two elements, the updated $results and the index of the next node.
*/
public function traverse($results, $key, $cascontext, $options)
{
$errorfree = true;
if ($cascontext->get_errors_key('PRSANS' . $key)) {
$results->_errors .= $cascontext->get_errors_key('PRSANS' . $key);
$results->add_feedback(' ' . stack_string('prtruntimeerror', array('node' => 'PRSANS' . ($key + 1), 'error' => $cascontext->get_errors_key('PRSANS' . $key))));
$errorfree = false;
}
if ($cascontext->get_errors_key('PRTANS' . $key)) {
$results->_errors .= $cascontext->get_errors_key('PRTANS' . $key);
$results->add_feedback(' ' . stack_string('prtruntimeerror', array('node' => 'PRTANS' . ($key + 1), 'error' => $cascontext->get_errors_key('PRTANS' . $key))));
$errorfree = false;
}
if ($cascontext->get_errors_key('PRATOPT' . $key)) {
$results->_errors .= $cascontext->get_errors_key('PRATOPT' . $key);
$results->add_feedback(' ' . stack_string('prtruntimeerror', array('node' => 'PRATOPT' . ($key + 1), 'error' => $cascontext->get_errors_key('PRATOPT' . $key))));
$errorfree = false;
}
if (!$errorfree) {
return -1;
}
$sans = $cascontext->get_value_key('PRSANS' . $key);
$tans = $cascontext->get_value_key('PRTANS' . $key);
$atopts = $cascontext->get_value_key('PRATOPT' . $key);
// If we can't find atopts then they were not processed by the CAS.
// They might still be some in the potential response which do not
// need to be processed.
if (false === $atopts) {
$atopts = null;
}
$nextnode = $this->do_test($sans, $tans, $atopts, $options, $results);
return $nextnode;
}
