/**
* Create a question_usage_by_activity from records loaded from the database.
*
* For internal use only.
*
* @param Iterator $records Raw records loaded from the database.
* @param int $questionattemptid The id of the question_attempt to extract.
* @return question_usage_by_activity The newly constructed usage.
*/
public static function load_from_records($records, $qubaid) {
$record = $records->current();
while ($record->qubaid != $qubaid) {
$records->next();
if (!$records->valid()) {
throw new coding_exception("Question usage $qubaid not found in the database.");
}
$record = $records->current();
}
$quba = new question_usage_by_activity($record->component,
context::instance_by_id($record->contextid, IGNORE_MISSING));
$quba->set_id_from_database($record->qubaid);
$quba->set_preferred_behaviour($record->preferredbehaviour);
$quba->observer = new question_engine_unit_of_work($quba);
// If slot is null 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->slot)) {
$records->next();
}
while ($record && $record->qubaid == $qubaid && !is_null($record->slot)) {
$quba->questionattempts[$record->slot] =
question_attempt::load_from_records($records,
$record->questionattemptid, $quba->observer,
$quba->get_preferred_behaviour());
if ($records->valid()) {
$record = $records->current();
} else {
$record = false;
}
}
return $quba;
}
/**
* Update a question_usages row to refect any changes in a usage (but not
* any of its question_attempts.
* @param question_usage_by_activity $quba the usage that has changed.
*/
public function update_questions_usage_by_activity(question_usage_by_activity $quba)
{
$record = new stdClass();
$record->id = $quba->get_id();
$record->contextid = $quba->get_owning_context()->id;
$record->component = $quba->get_owning_component();
$record->preferredbehaviour = $quba->get_preferred_behaviour();
$this->db->update_record('question_usages', $record);
}
/**
* Create a question_usage_by_activity from records loaded from the database.
*
* For internal use only.
*
* @param Iterator $records Raw records loaded from the database.
* @param int $questionattemptid The id of the question_attempt to extract.
* @return question_usage_by_activity The newly constructed usage.
*/
public static function load_from_records($records, $qubaid) {
$record = $records->current();
while ($record->qubaid != $qubaid) {
$records->next();
if (!$records->valid()) {
throw new coding_exception("Question usage $qubaid not found in the database.");
}
$record = $records->current();
}
$quba = new question_usage_by_activity($record->component,
get_context_instance_by_id($record->contextid));
$quba->set_id_from_database($record->qubaid);
$quba->set_preferred_behaviour($record->preferredbehaviour);
$quba->observer = new question_engine_unit_of_work($quba);
while ($record && $record->qubaid == $qubaid && !is_null($record->slot)) {
$quba->questionattempts[$record->slot] =
question_attempt::load_from_records($records,
$record->questionattemptid, $quba->observer,
$quba->get_preferred_behaviour());
if ($records->valid()) {
$record = $records->current();
} else {
$record = false;
}
}
return $quba;
}
