/**
* This action is the quiz shell.
* It ensures permissions, creates new attempts etc etc.
*
* @author Ben Evans
*/
public function attemptAction()
{
Model_Shell_Debug::getInstance()->log("User Entered the Attempt Action");
$identity = Zend_Auth::getInstance()->getIdentity();
$username = $identity->username;
$auth_model = Model_Auth_General::getAuthModel();
/* Before we do anything, test to make sure we've passed a VALID QUIZ which WE ARE ENTITLED to sit. */
$quiz_id = $this->_getParam("quiz");
if (is_null($quiz_id)) {
throw new Exception("No quiz was passed. Cannot continue.");
}
$vQuiz = Model_Quiz_Quiz::fromID($quiz_id);
if ($vQuiz == null) {
throw new Exception("Quiz ID passed was invalid. Cannot continue.");
}
$mFinished = false;
$mMarking = false;
//Permissions
if ($auth_model->userInGroup($username, $vQuiz->getPermissions_group()) && $vQuiz->getOpen_date() <= strtotime("now")) {
//Have we run out of attempts?
$vAttempts = Model_Quiz_QuizAttempt::getAllFromUser($username, $vQuiz);
if (sizeof($vAttempts) >= $vQuiz->getMax_attempts()) {
//It is possible that we're on our last attempt, and that it's "in progress"...check
$bInProgress = false;
foreach ($vAttempts as $vAttempt) {
if ($vAttempt->getDate_finished() == null) {
$bInProgress = true;
}
}
if (!$bInProgress) {
throw new Exception("You've exceeded your maximum attempts for this quiz. Cannot continue");
}
}
} else {
if (!$this->view->is_admin) {
throw new Exception("Insufficient Permissions to take this quiz / Quiz not open yet");
}
$vAttempts = Model_Quiz_QuizAttempt::getAllFromUser($username, $vQuiz);
}
/* Ok. We're allowed to TAKE the quiz. Are we resuming, or starting a new one? */
$mQuizAttempt = null;
if (is_array($vAttempts)) {
foreach ($vAttempts as $vAttempt) {
if ($vAttempt->getDate_finished() == null) {
$mQuizAttempt = $vAttempt;
break;
}
}
//End Foreach
}
//End If
if ($mQuizAttempt == null) {
$mQuizAttempt = Model_Quiz_QuizAttempt::fromScratch(strtotime("now"), $vQuiz, $username);
}
/* Calculate the total questions needed for this quiz */
$vTCs = $vQuiz->getTestedConcepts();
$vTotalQuestions = 0;
foreach ($vTCs as $vTC) {
$vTotalQuestions = $vTotalQuestions + $vTC->getNumber_tested();
}
/* We have our quizAttempt ready to go. Now we look to see if we're resuming a question or not */
$mQuestionAttempt = $mQuizAttempt->getLastIncompleteQuestion();
if (is_object($mQuestionAttempt) && !$mQuestionAttempt->isValid()) {
$mQuestionAttempt->destroy();
// Remove the Question attempt (Database was reinitialised or something)
$mQuestionAttempt = null;
}
if ($mQuestionAttempt != null) {
/* Are we getting an ANSWER for this question? */
if (array_key_exists("marking", $_POST) && $_POST['marking'] == "1") {
/* Mark it */
$mMarking = true;
}
/* If we reach here, the page has probably been refreshed. We just re-display the last question */
} else {
/* Have we finished this quiz? */
if ($mQuizAttempt->getQuestionAttemptCount() >= $vTotalQuestions) {
//Close this attempt and display a result later on down the page
$mQuizAttempt->setDate_finished(strtotime("now"));
//Calculate and store the final score
$mQuizAttempt->setTotal_score($mQuizAttempt->getTotal_score());
$mFinished = true;
} else {
/* QuizAttempt isn't finished... Fetch a questionBase */
$vQuestionBase = Model_Shell_QuestionChooser::select_next_question($mQuizAttempt, true);
/* Make a GeneratedQuestion */
$vCounter = 0;
//Make sure we don't get any fluke no-text answers
while ($vCounter < 3) {
Model_Shell_Debug::getInstance()->log("vQuestionBase: " . isset($vQuestionBase));
Model_Shell_Debug::getInstance()->log("Generating... from " . $vQuestionBase->getXml());
$vGen = Model_Quiz_GeneratedQuestion::fromQuestionBase($vQuestionBase);
if ($vGen->getCorrect_answer() != "" && $vGen->getCorrect_answer() != "\r\n") {
break;
} else {
$vGen->remove();
}
$vCounter++;
}
if ($vGen->getCorrect_answer() == "" || $vGen->getCorrect_answer() == "\r\n") {
throw new Exception("Error. While generating a question for you, blank answers appeared > 3 times. This should never happen. Either try to refresh this page, or consult your lecturer...");
}
/* Make a QuestionAttempt */
$mQuestionAttempt = Model_Quiz_QuestionAttempt::fromScratch($vQuestionBase, strtotime("now"), strtotime("now"), $mQuizAttempt, $vGen);
}
//End-if_finished_quizAttempt
}
// Pass all relevant information to the view
$this->view->quiz = $vQuiz;
$this->view->question_attempt = $mQuestionAttempt;
$this->view->finished = $mFinished;
$this->view->marking = $mMarking;
$this->view->mQuizAttempt = $mQuizAttempt;
$this->view->vTotalQuestions = $vTotalQuestions;
}
/**
* Selects the next question base appropriate for the quiz attempt passed
* @param Model_Quiz_QuizAttempt $vQuizAttempt
* @param boolean $debug Being Phased out TODO
* @throws Exception
* @return Model_Quiz_QuestionBase|NULL NULL Should only be returned in exceptional circumstances
*/
public static function select_next_question($vQuizAttempt, $debug = false)
{
//Get all the concepts this quiz tests
$vQuiz = $vQuizAttempt->getQuiz();
$vTestedConcepts = $vQuiz->getTestedConcepts();
if (sizeof($vTestedConcepts) < 1) {
throw new Exception("This quiz is not ready yet - reason: No testedConcepts specified.");
}
//Foreach concept tested, see how many questions we've attempted
foreach ($vTestedConcepts as $vTestedConcept) {
Model_Shell_Debug::getInstance()->log("Looking at TestedConcept: " . $vTestedConcept->getConcept()->getConcept_name());
$vQuestionAttempts = Model_Quiz_QuestionAttempt::getAllFromQuizAttemptAndConcept($vQuizAttempt, $vTestedConcept->getConcept());
Model_Shell_Debug::getInstance()->log("Done " . sizeof($vQuestionAttempts) . "/" . $vTestedConcept->getNumber_tested());
//If we haven't attempted enough in this concept, we need to choose a question difficulty
if (sizeof($vQuestionAttempts) < $vTestedConcept->getNumber_tested()) {
//What difficulties are there being tested within this concept?
$vLowest = $vTestedConcept->getLower_difficulty();
$vHighest = $vTestedConcept->getHigher_difficulty();
//Find out how many questions I should allocate for each difficulty
$mQuestionsPerDifficultyLevel = floor(0.8 / ($vHighest + 1 - $vLowest) * $vTestedConcept->getNumber_tested());
$mBuffer = $vTestedConcept->getNumber_tested() - ($vHighest + 1 - $vLowest) * $mQuestionsPerDifficultyLevel;
//If there's only one difficulty, that settles that
if ($vLowest == $vHighest) {
return Model_Shell_QuestionChooser::select_next_question_2($vQuizAttempt, $vTestedConcept->getConcept(), $vLowest);
}
//Were there any previous attempts at this concept? If not, we need to start a Q at the lowest specified difficulty
$vQuestionAttempts = $vQuizAttempt->getQuestionAttempts($vTestedConcept->getConcept());
//echo "Size of vQuestionAttempts:".sizeof($vQuestionAttempts)."<br/>";
if (sizeof($vQuestionAttempts) == 0) {
return Model_Shell_QuestionChooser::select_next_question_2($vQuizAttempt, $vTestedConcept->getConcept(), $vLowest);
}
//Find the highest attempted difficulty done so far
$vHighestSoFar = $vQuizAttempt->getHighestDifficultyTestedSoFar();
//echo "The highest difficulty so far: $vHighestSoFar<br/>";
if ($vHighestSoFar >= $vHighest) {
//Already at the highest difficulty, the next question will be at this difficulty too
return Model_Shell_QuestionChooser::select_next_question_2($vQuizAttempt, $vTestedConcept->getConcept(), $vHighest);
}
//Look at the last attempts in this difficulty. Were they below-par (use a percentage?)?
$vTotal = 0;
$vTotalRight = 0;
Model_Shell_Debug::getInstance()->log("Checking your previous attempts...Size of vQuestionAttempts:" . sizeof($vQuestionAttempts));
foreach ($vQuestionAttempts as $vQA) {
$vQB = $vQA->getQuestion_base();
//echo "Looking at " . $vQB->getDifficulty() . " vs $vHighestSoFar<br/>";
if ($vQB->getDifficulty() == $vHighestSoFar) {
$vTotal++;
if ($vQB->getEstimated_time() > $vQA->getTime_finished() - $vQA->getTime_started()) {
//You did this question in a reasonable time... did you get it right first time?
if ($vQA->getInitial_result() == "1") {
$vTotalRight++;
}
}
}
}
//Note, a divide by 0 happened here before...
if ($vTotal == 0 || $vTotalRight / $vTotal > 0.8) {
//OK. If they WERE good attempts, I should move on if I've hit my quota for this difficulty
if ($vTotal >= $mQuestionsPerDifficultyLevel) {
//Reached our minumum quota for this difficulty level. NEXT!
return Model_Shell_QuestionChooser::select_next_question_2($vQuizAttempt, $vTestedConcept->getConcept(), $vHighestSoFar + 1);
} else {
//We've done well so far, but we need to do more in this difficulty
return Model_Shell_QuestionChooser::select_next_question_2($vQuizAttempt, $vTestedConcept->getConcept(), $vHighestSoFar);
}
} else {
//Your previous attempts weren't all that good.
//Figure out how much buffer we have left. Can we afford to give you a question at $vHighestSoFar? Or do we have to move onto something harder?
$mBuffer = $vTestedConcept->getNumber_tested() - ($vHighest - $vHighestSoFar) * $mQuestionsPerDifficultyLevel - sizeof($vQuestionAttempts);
if ($mBuffer > 1) {
//We can afford to give you another easier question
return Model_Shell_QuestionChooser::select_next_question_2($vQuizAttempt, $vTestedConcept->getConcept(), $vHighestSoFar);
} else {
//Sorry.. buffer is dry. You weren't going too well, but you gotta do the harder stuff
return Model_Shell_QuestionChooser::select_next_question_2($vQuizAttempt, $vTestedConcept->getConcept(), $vHighestSoFar + 1);
}
}
}
//End If
}
//End Foreach testedConcept
//We shouldn't really ever get here, but in case we do -> null
return null;
}
protected function makeQuestionAttempt($quizAttempt, $now)
{
$questionBase = Model_Shell_QuestionChooser::select_next_question($quizAttempt, true);
$path = $this->getFrontController()->getParam('xml_path');
// This way we can set it externally from our tests. If not set, called code will just use the configuration value
/* Make a GeneratedQuestion */
$cnt = 0;
// Make sure we don't get any fluke no-text answers
while ($cnt < 3) {
Model_Shell_Debug::getInstance()->log("vQuestionBase: " . isset($questionBase));
Model_Shell_Debug::getInstance()->log("Generating... from " . $questionBase->getXml());
$vGen = Model_Quiz_GeneratedQuestion::fromQuestionBase($questionBase, $path);
if ($vGen->getCorrect_answer() != "" && $vGen->getCorrect_answer() != "\r\n") {
break;
} else {
$vGen->remove();
}
$cnt++;
}
if ($vGen->getCorrect_answer() == "" || $vGen->getCorrect_answer() == "\r\n") {
throw new Exception("Error. While generating a question for you, blank answers appeared > 3 times. This should never happen. Either try to refresh this page, or consult your lecturer...");
}
/* Make a QuestionAttempt */
return Model_Quiz_QuestionAttempt::fromScratch($questionBase, $now, $now, $quizAttempt, $vGen);
}
