/**
* Helper function for save() to update the uses of questions and delete
* unused questions.
*/
private static function updateQuestionUses(MongoId $jobId, array $oldQuestions, array $newQuestions)
{
$commonQuestions = array_intersect($newQuestions, $oldQuestions);
$removedQuestions = array_diff($oldQuestions, $commonQuestions);
$addedQuestions = array_diff($newQuestions, $commonQuestions);
foreach ($removedQuestions as $questionId) {
QuestionModel::removeFromUses($questionId, $jobId);
}
foreach ($addedQuestions as $questionId) {
QuestionModel::addToUses($questionId, $jobId);
}
}
