protected function decode_random_attempt($qstates, $maxmark)
{
$realquestionid = null;
foreach ($qstates as $i => $state) {
if (strpos($state->answer, '-') < 6) {
// Broken state, skip it.
$this->logger->log_assumption("Had to skip brokes state {$state->id}\n for question {$state->question}.");
unset($qstates[$i]);
continue;
}
list($randombit, $realanswer) = explode('-', $state->answer, 2);
$newquestionid = substr($randombit, 6);
if ($realquestionid && $realquestionid != $newquestionid) {
throw new coding_exception("Question session {$this->qsession->id}\n for random question points to two different real questions\n {$realquestionid} and {$newquestionid}.");
}
$qstates[$i]->answer = $realanswer;
}
if (empty($newquestionid)) {
// This attempt only had broken states. Set a fake $newquestionid to
// prevent a null DB error later.
$newquestionid = 0;
}
$newquestion = $this->load_question($newquestionid);
$newquestion->maxmark = $maxmark;
return array($newquestion, $qstates);
}
protected function process0($step, $state)
{
if ($this->startstate) {
if ($state->answer == reset($this->qstates)->answer) {
return;
} else {
if ($this->quiz->attemptonlast && $this->sequencenumber == 1) {
// There was a bug in attemptonlast in the past, which meant that
// it created two inconsistent open states, with the second taking
// priority. Simulate that be discarding the first open state, then
// continuing.
$this->logger->log_assumption("Ignoring bogus state in attempt at question {$state->question}");
$this->sequencenumber = 0;
$this->qa->steps = array();
} else {
if ($state->answer == '') {
$this->logger->log_assumption("Ignoring second start state with blank answer in attempt at question {$state->question}");
return;
} else {
throw new coding_exception("Two inconsistent open states for question session {$this->qsession->id}.");
}
}
}
}
$step->state = 'todo';
$this->startstate = $state;
$this->add_step($step);
}