private function getRandomToken($studentId)
{
$t = new Token($this->tokenAlphabet, $this->tokenLength);
// check for existing tokens
while ($this->checkToken($studentId, $t->getString())) {
$t = Token($this->tokenAlphabet, $this->tokenLength);
}
return $t->getString();
}
function Data_Retrieval($in_file)
{
$data = "";
$temp_string = "";
$temp_element = 0;
$complete_label = FALSE;
$file = fopen($in_file, "r") or exit($in_file);
while (!feof($file)) {
$bufer = htmlspecialchars(fgets($file)) . "<br />";
}
fclose($file);
$token = explode("%", $bufer);
foreach ($token as $element) {
$pos = strpos($element, "?xml");
if ($pos > 0) {
if (substr($element, 0, 2) == "0A") {
$element = substr($element, 21);
$data .= "///";
$temp_element = 0;
}
if ($pos = strpos($element, "date_time=")) {
$data .= substr($element, $pos + 16, 25);
}
if ($pos = strpos($element, "action_id=")) {
$temp_string .= substr($element, $pos, 50);
if ($pos = strpos($temp_string, "context_message")) {
$data .= ";;;context_message";
$temp_element = 1;
} elseif ($pos = strpos($temp_string, "tool_message")) {
$data .= ";;;tool_message";
$temp_element = 2;
} elseif ($pos = strpos($temp_string, "tutor_message")) {
$data .= ";;;tutor_message";
$temp_element = 3;
}
}
} else {
if (strlen($element) == 2) {
$temp_string = Token($element) . " ";
if (Token($element) == ">") {
$complete_label = TRUE;
}
} else {
$temp_string .= Token(substr($element, 0, 2)) . " ";
$temp_string .= substr($element, 2) . " ";
if (Token(substr($element, 0, 2)) == ">") {
$complete_label = TRUE;
}
}
if ($complete_label == TRUE) {
switch ($temp_element) {
case 2:
if ($pos = strpos($temp_string, "< selection >")) {
$data .= ";;;" . substr($temp_string, $pos + 14);
}
if ($pos = strpos($temp_string, "< input >")) {
$data .= "->" . substr($temp_string, $pos + 10);
}
break;
case 3:
if ($pos = strpos($temp_string, "< action_evaluation >")) {
$data .= ";;;" . substr($temp_string, $pos + 22);
}
if ($pos = strpos($temp_string, "< tutor_advice >")) {
$data .= "->" . substr($temp_string, $pos + 17);
}
break;
}
$complete_label = FALSE;
$temp_string = "";
}
}
}
return $data;
}
