PHP question_usage_by_activity::next_slot_number方法代码示例

/**
 * Start a normal, new, quiz attempt.
 *
 * @param quiz      $quizobj            the quiz object to start an attempt for.
 * @param question_usage_by_activity $quba
 * @param object    $attempt
 * @param integer   $attemptnumber      starting from 1
 * @param integer   $timenow            the attempt start time
 * @param array     $questionids        slot number => question id. Used for random questions, to force the choice
 *                                        of a particular actual question. Intended for testing purposes only.
 * @param array     $forcedvariantsbyslot slot number => variant. Used for questions with variants,
 *                                          to force the choice of a particular variant. Intended for testing
 *                                          purposes only.
 * @throws moodle_exception
 * @return object   modified attempt object
 */
function quiz_start_new_attempt($quizobj, $quba, $attempt, $attemptnumber, $timenow,
                                $questionids = array(), $forcedvariantsbyslot = array()) {
    // Fully load all the questions in this quiz.
    $quizobj->preload_questions();
    $quizobj->load_questions();

    // Add them all to the $quba.
    $idstoslots = array();
    $questionsinuse = array_keys($quizobj->get_questions());
    foreach ($quizobj->get_questions() as $i => $questiondata) {
        if ($questiondata->qtype != 'random') {
            if (!$quizobj->get_quiz()->shuffleanswers) {
                $questiondata->options->shuffleanswers = false;
            }
            $question = question_bank::make_question($questiondata);

        } else {
            if (!isset($questionids[$quba->next_slot_number()])) {
                $forcequestionid = null;
            } else {
                $forcequestionid = $questionids[$quba->next_slot_number()];
            }

            $question = question_bank::get_qtype('random')->choose_other_question(
                $questiondata, $questionsinuse, $quizobj->get_quiz()->shuffleanswers, $forcequestionid);
            if (is_null($question)) {
                throw new moodle_exception('notenoughrandomquestions', 'quiz',
                                           $quizobj->view_url(), $questiondata);
            }
        }

        $idstoslots[$i] = $quba->add_question($question, $questiondata->maxmark);
        $questionsinuse[] = $question->id;
    }

    // Start all the questions.
    if ($attempt->preview) {
        $variantoffset = rand(1, 100);
    } else {
        $variantoffset = $attemptnumber;
    }
    $variantstrategy = new question_variant_pseudorandom_no_repeats_strategy(
            $variantoffset, $attempt->userid, $quizobj->get_quizid());

    if (!empty($forcedvariantsbyslot)) {
        $forcedvariantsbyseed = question_variant_forced_choices_selection_strategy::prepare_forced_choices_array(
            $forcedvariantsbyslot, $quba);
        $variantstrategy = new question_variant_forced_choices_selection_strategy(
            $forcedvariantsbyseed, $variantstrategy);
    }

    $quba->start_all_questions($variantstrategy, $timenow);

    // Update attempt layout.
    $newlayout = array();
    foreach (explode(',', $attempt->layout) as $qid) {
        if ($qid != 0) {
            $newlayout[] = $idstoslots[$qid];
        } else {
            $newlayout[] = 0;
        }
    }
    $attempt->layout = implode(',', $newlayout);
    return $attempt;
}

/**
 * Start a normal, new, quiz attempt.
 *
 * @param quiz      $quizobj            the quiz object to start an attempt for.
 * @param question_usage_by_activity $quba
 * @param object    $attempt
 * @param integer   $attemptnumber      starting from 1
 * @param integer   $timenow            the attempt start time
 * @param array     $questionids        slot number => question id. Used for random questions, to force the choice
 *                                        of a particular actual question. Intended for testing purposes only.
 * @param array     $forcedvariantsbyslot slot number => variant. Used for questions with variants,
 *                                          to force the choice of a particular variant. Intended for testing
 *                                          purposes only.
 * @throws moodle_exception
 * @return object   modified attempt object
 */
function quiz_start_new_attempt($quizobj, $quba, $attempt, $attemptnumber, $timenow, $questionids = array(), $forcedvariantsbyslot = array())
{
    // Usages for this user's previous quiz attempts.
    $qubaids = new \mod_quiz\question\qubaids_for_users_attempts($quizobj->get_quizid(), $attempt->userid);
    // Fully load all the questions in this quiz.
    $quizobj->preload_questions();
    $quizobj->load_questions();
    // First load all the non-random questions.
    $randomfound = false;
    $slot = 0;
    $questions = array();
    $maxmark = array();
    $page = array();
    foreach ($quizobj->get_questions() as $questiondata) {
        $slot += 1;
        $maxmark[$slot] = $questiondata->maxmark;
        $page[$slot] = $questiondata->page;
        if ($questiondata->qtype == 'random') {
            $randomfound = true;
            continue;
        }
        if (!$quizobj->get_quiz()->shuffleanswers) {
            $questiondata->options->shuffleanswers = false;
        }
        $questions[$slot] = question_bank::make_question($questiondata);
    }
    // Then find a question to go in place of each random question.
    if ($randomfound) {
        $slot = 0;
        $usedquestionids = array();
        foreach ($questions as $question) {
            if (isset($usedquestions[$question->id])) {
                $usedquestionids[$question->id] += 1;
            } else {
                $usedquestionids[$question->id] = 1;
            }
        }
        $randomloader = new \core_question\bank\random_question_loader($qubaids, $usedquestionids);
        foreach ($quizobj->get_questions() as $questiondata) {
            $slot += 1;
            if ($questiondata->qtype != 'random') {
                continue;
            }
            // Deal with fixed random choices for testing.
            if (isset($questionids[$quba->next_slot_number()])) {
                if ($randomloader->is_question_available($questiondata->category, (bool) $questiondata->questiontext, $questionids[$quba->next_slot_number()])) {
                    $questions[$slot] = question_bank::load_question($questionids[$quba->next_slot_number()], $quizobj->get_quiz()->shuffleanswers);
                    continue;
                } else {
                    throw new coding_exception('Forced question id not available.');
                }
            }
            // Normal case, pick one at random.
            $questionid = $randomloader->get_next_question_id($questiondata->category, (bool) $questiondata->questiontext);
            if ($questionid === null) {
                throw new moodle_exception('notenoughrandomquestions', 'quiz', $quizobj->view_url(), $questiondata);
            }
            $questions[$slot] = question_bank::load_question($questionid, $quizobj->get_quiz()->shuffleanswers);
        }
    }
    // Finally add them all to the usage.
    ksort($questions);
    foreach ($questions as $slot => $question) {
        $newslot = $quba->add_question($question, $maxmark[$slot]);
        if ($newslot != $slot) {
            throw new coding_exception('Slot numbers have got confused.');
        }
    }
    // Start all the questions.
    $variantstrategy = new core_question\engine\variants\least_used_strategy($quba, $qubaids);
    if (!empty($forcedvariantsbyslot)) {
        $forcedvariantsbyseed = question_variant_forced_choices_selection_strategy::prepare_forced_choices_array($forcedvariantsbyslot, $quba);
        $variantstrategy = new question_variant_forced_choices_selection_strategy($forcedvariantsbyseed, $variantstrategy);
    }
    $quba->start_all_questions($variantstrategy, $timenow);
    // Work out the attempt layout.
    $sections = $quizobj->get_sections();
    foreach ($sections as $i => $section) {
        if (isset($sections[$i + 1])) {
            $sections[$i]->lastslot = $sections[$i + 1]->firstslot - 1;
        } else {
            $sections[$i]->lastslot = count($questions);
        }
    }
//.........这里部分代码省略.........