/**
* Create a fake question to be displayed in place of a question that is blocked
* until the previous question has been answered.
*
* @param int $slot int slot number of the question to replace.
* @return question_definition the placeholde question.
*/
protected function make_blocked_question_placeholder($slot)
{
$replacedquestion = $this->get_question_attempt($slot)->get_question();
question_bank::load_question_definition_classes('description');
$question = new qtype_description_question();
$question->id = $replacedquestion->id;
$question->category = null;
$question->parent = 0;
$question->qtype = question_bank::get_qtype('description');
$question->name = '';
$question->questiontext = get_string('questiondependsonprevious', 'quiz');
$question->questiontextformat = FORMAT_HTML;
$question->generalfeedback = '';
$question->defaultmark = $this->quba->get_question_max_mark($slot);
$question->length = $replacedquestion->length;
$question->penalty = 0;
$question->stamp = '';
$question->version = 0;
$question->hidden = 0;
$question->timecreated = null;
$question->timemodified = null;
$question->createdby = null;
$question->modifiedby = null;
$placeholderqa = new question_attempt($question, $this->quba->get_id(), null, $this->quba->get_question_max_mark($slot));
$placeholderqa->set_slot($slot);
$placeholderqa->start($this->get_quiz()->preferredbehaviour, 1);
$placeholderqa->set_flagged($this->is_question_flagged($slot));
return $placeholderqa;
}
/**
* Regrade a question in this usage. This replays the sequence of submitted
* actions to recompute the outcomes.
* @param int $slot the number used to identify this question within this usage.
* @param bool $finished whether the question attempt should be forced to be finished
* after the regrade, or whether it may still be in progress (default false).
* @param number $newmaxmark (optional) if given, will change the max mark while regrading.
*/
public function regrade_question($slot, $finished = false, $newmaxmark = null) {
$oldqa = $this->get_question_attempt($slot);
if (is_null($newmaxmark)) {
$newmaxmark = $oldqa->get_max_mark();
}
$newqa = new question_attempt($oldqa->get_question(), $oldqa->get_usage_id(),
$this->observer, $newmaxmark);
$newqa->set_database_id($oldqa->get_database_id());
$newqa->set_slot($oldqa->get_slot());
$newqa->regrade($oldqa, $finished);
$this->questionattempts[$slot] = $newqa;
$this->observer->notify_attempt_modified($newqa);
}
/**
* Create a question_attempt_step from records loaded from the database.
*
* For internal use only.
*
* @param Iterator $records Raw records loaded from the database.
* @param int $questionattemptid The id of the question_attempt to extract.
* @return question_attempt The newly constructed question_attempt.
*/
public static function load_from_records($records, $questionattemptid, question_usage_observer $observer, $preferredbehaviour)
{
$record = $records->current();
while ($record->questionattemptid != $questionattemptid) {
$record = $records->next();
if (!$records->valid()) {
throw new coding_exception("Question attempt {$questionattemptid} not found in the database.");
}
$record = $records->current();
}
try {
$question = question_bank::load_question($record->questionid);
} catch (Exception $e) {
// The question must have been deleted somehow. Create a missing
// question to use in its place.
$question = question_bank::get_qtype('missingtype')->make_deleted_instance($record->questionid, $record->maxmark + 0);
}
$qa = new question_attempt($question, $record->questionusageid, null, $record->maxmark + 0);
$qa->set_database_id($record->questionattemptid);
$qa->set_slot($record->slot);
$qa->variant = $record->variant + 0;
$qa->minfraction = $record->minfraction + 0;
$qa->maxfraction = $record->maxfraction + 0;
$qa->set_flagged($record->flagged);
$qa->questionsummary = $record->questionsummary;
$qa->rightanswer = $record->rightanswer;
$qa->responsesummary = $record->responsesummary;
$qa->timemodified = $record->timemodified;
$qa->behaviour = question_engine::make_behaviour($record->behaviour, $qa, $preferredbehaviour);
$qa->observer = $observer;
// If attemptstepid is null (which should not happen, but has happened
// due to corrupt data, see MDL-34251) then the current pointer in $records
// will not be advanced in the while loop below, and we get stuck in an
// infinite loop, since this method is supposed to always consume at
// least one record. Therefore, in this case, advance the record here.
if (is_null($record->attemptstepid)) {
$records->next();
}
$i = 0;
$autosavedstep = null;
$autosavedsequencenumber = null;
while ($record && $record->questionattemptid == $questionattemptid && !is_null($record->attemptstepid)) {
$sequencenumber = $record->sequencenumber;
$nextstep = question_attempt_step::load_from_records($records, $record->attemptstepid, $qa->get_question()->get_type_name());
if ($sequencenumber < 0) {
if (!$autosavedstep) {
$autosavedstep = $nextstep;
$autosavedsequencenumber = -$sequencenumber;
} else {
// Old redundant data. Mark it for deletion.
$qa->observer->notify_step_deleted($nextstep, $qa);
}
} else {
$qa->steps[$i] = $nextstep;
if ($i == 0) {
$question->apply_attempt_state($qa->steps[0]);
}
$i++;
}
if ($records->valid()) {
$record = $records->current();
} else {
$record = false;
}
}
if ($autosavedstep) {
if ($autosavedsequencenumber >= $i) {
$qa->autosavedstep = $autosavedstep;
$qa->steps[$i] = $qa->autosavedstep;
} else {
$qa->observer->notify_step_deleted($autosavedstep, $qa);
}
}
return $qa;
}
/**
* Create a question_attempt_step from records loaded from the database.
*
* For internal use only.
*
* @param Iterator $records Raw records loaded from the database.
* @param int $questionattemptid The id of the question_attempt to extract.
* @return question_attempt The newly constructed question_attempt.
*/
public static function load_from_records($records, $questionattemptid,
question_usage_observer $observer, $preferredbehaviour) {
$record = $records->current();
while ($record->questionattemptid != $questionattemptid) {
$record = $records->next();
if (!$records->valid()) {
throw new coding_exception("Question attempt $questionattemptid not found in the database.");
}
$record = $records->current();
}
try {
$question = question_bank::load_question($record->questionid);
} catch (Exception $e) {
// The question must have been deleted somehow. Create a missing
// question to use in its place.
$question = question_bank::get_qtype('missingtype')->make_deleted_instance(
$record->questionid, $record->maxmark + 0);
}
$qa = new question_attempt($question, $record->questionusageid,
null, $record->maxmark + 0);
$qa->set_database_id($record->questionattemptid);
$qa->set_slot($record->slot);
$qa->variant = $record->variant + 0;
$qa->minfraction = $record->minfraction + 0;
$qa->set_flagged($record->flagged);
$qa->questionsummary = $record->questionsummary;
$qa->rightanswer = $record->rightanswer;
$qa->responsesummary = $record->responsesummary;
$qa->timemodified = $record->timemodified;
$qa->behaviour = question_engine::make_behaviour(
$record->behaviour, $qa, $preferredbehaviour);
$i = 0;
while ($record && $record->questionattemptid == $questionattemptid && !is_null($record->attemptstepid)) {
$qa->steps[$i] = question_attempt_step::load_from_records($records, $record->attemptstepid);
if ($i == 0) {
$question->apply_attempt_state($qa->steps[0]);
}
$i++;
if ($records->valid()) {
$record = $records->current();
} else {
$record = false;
}
}
$qa->observer = $observer;
return $qa;
}