Admin: add config setting "quiz_prevent_backwards_move" #3100

Requires DB change.
Exercises: Prevent going back to previous questions

main/exercise/exercise.class.php

@@ -89,6 +89,7 @@ class Exercise
     public $autolaunch;
     public $exerciseCategoryId;
     public $pageResultConfiguration;
+    public $preventBackwards;
 
     /**
      * Constructor of the class.
@@ -129,6 +130,7 @@ class Exercise
         $this->notifications = [];
         $this->exerciseCategoryId = null;
         $this->pageResultConfiguration;
+        $this->preventBackwards = 0;
 
         if (!empty($courseId)) {
             $courseInfo = api_get_course_info_by_id($courseId);
@@ -201,6 +203,7 @@ class Exercise
             $this->hideQuestionTitle = isset($object->hide_question_title) ? (int) $object->hide_question_title : 0;
             $this->autolaunch = isset($object->autolaunch) ? (int) $object->autolaunch : 0;
             $this->exerciseCategoryId = isset($object->exercise_category_id) ? (int) $object->exercise_category_id : null;
+            $this->preventBackwards = isset($object->prevent_backwards) ? (int) $object->prevent_backwards : 0;
 
             $this->notifications = [];
             if (!empty($object->notifications)) {
@@ -1588,6 +1591,10 @@ class Exercise
                     $paramsExtra['show_previous_button'] = $this->showPreviousButton();
                 }
 
+                if (api_get_configuration_value('quiz_prevent_backwards_move')) {
+                    $paramsExtra['prevent_backwards'] = $this->getPreventBackwards();
+                }
+
                 $allow = api_get_configuration_value('allow_exercise_categories');
                 if ($allow === true) {
                     if (!empty($this->getExerciseCategoryId())) {
@@ -1678,6 +1685,10 @@ class Exercise
                 }
             }
 
+            if (api_get_configuration_value('quiz_prevent_backwards_move')) {
+                $params['prevent_backwards'] = $this->getPreventBackwards();
+            }
+
             $allow = api_get_configuration_value('allow_quiz_show_previous_button_setting');
             if ($allow === true) {
                 $params['show_previous_button'] = $this->showPreviousButton();
@@ -2372,6 +2383,14 @@ class Exercise
                 get_lang('UpdateTitleInLps')
             );
 
+            if (api_get_configuration_value('quiz_prevent_backwards_move')) {
+                $form->addCheckBox(
+                    'prevent_backwards',
+                    null,
+                    get_lang('QuizPreventBackwards')
+                );
+            }
+
             $defaults = [];
             if (api_get_setting('search_enabled') === 'true') {
                 require_once api_get_path(LIBRARY_PATH).'specific_fields_manager.lib.php';
@@ -2451,6 +2470,7 @@ class Exercise
                 $defaults['hide_question_title'] = $this->getHideQuestionTitle();
                 $defaults['show_previous_button'] = $this->showPreviousButton();
                 $defaults['exercise_category_id'] = $this->getExerciseCategoryId();
+                $defaults['prevent_backwards'] = $this->getPreventBackwards();
 
                 if (!empty($this->start_time)) {
                     $defaults['activate_start_date_check'] = 1;
@@ -2632,6 +2652,7 @@ class Exercise
         $this->setNotifications($form->getSubmitValue('notifications'));
         $this->setExerciseCategoryId($form->getSubmitValue('exercise_category_id'));
         $this->setPageResultConfiguration($form->getSubmitValues());
+        $this->preventBackwards = (int) $form->getSubmitValue('prevent_backwards');
 
         $this->start_time = null;
         if ($form->getSubmitValue('activate_start_date_check') == 1) {
@@ -3224,7 +3245,7 @@ class Exercise
                                 }
                             }
 
-                            if ($showPreview) {
+                            if ($showPreview && 0 === $this->getPreventBackwards()) {
                                 $buttonList[] = Display::button(
                                     'previous_question_and_save',
                                     get_lang('PreviousQuestion'),
@@ -7941,6 +7962,16 @@ class Exercise
         return $this->showPreviousButton;
     }
 
+    public function getPreventBackwards()
+    {
+        $allow = api_get_configuration_value('quiz_prevent_backwards_move');
+        if ($allow === false) {
+            return 0;
+        }
+
+        return (int) $this->preventBackwards;
+    }
+
     /**
      * @return int
      */

main/exercise/exercise_admin.php

@@ -1,4 +1,5 @@
 <?php
+
 /* For licensing terms, see /license.txt */
 
 use ChamiloSession as Session;
@@ -7,9 +8,6 @@ use ChamiloSession as Session;
  * Exercise administration
  * This script allows to manage an exercise. It is included from
  * the script admin.php.
- *
- * @package chamilo.exercise
- *
  * @author Olivier Brouckaert, Julio Montoya
  */
 require_once __DIR__.'/../inc/global.inc.php';

main/exercise/exercise_submit.php

@@ -43,7 +43,7 @@ $sessionId = api_get_session_id();
 $glossaryExtraTools = api_get_setting('show_glossary_in_extra_tools');
 
 $showGlossary = in_array($glossaryExtraTools, ['true', 'exercise', 'exercise_and_lp']);
-if ($origin == 'learnpath') {
+if ($origin === 'learnpath') {
     $showGlossary = in_array($glossaryExtraTools, ['true', 'lp', 'exercise_and_lp']);
 }
 if ($showGlossary) {
@@ -122,7 +122,7 @@ if (api_is_allowed_to_edit(null, true) &&
 // 1. Loading the $objExercise variable
 /** @var \Exercise $exerciseInSession */
 $exerciseInSession = Session::read('objExercise');
-if (!isset($exerciseInSession) || isset($exerciseInSession) && ($exerciseInSession->id != $_GET['exerciseId'])) {
+if (empty($exerciseInSession) || (!empty($exerciseInSession) && ($exerciseInSession->id != $_GET['exerciseId']))) {
     // Construction of Exercise
     $objExercise = new Exercise($courseId);
     Session::write('firstTime', true);
@@ -159,6 +159,8 @@ if (!isset($objExercise) && isset($exerciseInSession)) {
     $objExercise = $exerciseInSession;
 }
 
+$exerciseInSession = Session::read('objExercise');
+
 //3. $objExercise is not set, then return to the exercise list
 if (!is_object($objExercise)) {
     if ($debug) {
@@ -1406,6 +1408,15 @@ if (!empty($error)) {
                         break;
                     }
                 }
+
+                if (1 === $exerciseInSession->getPreventBackwards()) {
+                    if (isset($attempt_list[$questionId])) {
+                        echo Display::return_message(get_lang('AlreadyAnswered'));
+                        $i++;
+                        break;
+                    }
+                }
+
             }
         }
 

main/install/configuration.dist.php

@@ -1391,6 +1391,10 @@ ALTER TABLE notification_event ADD COLUMN event_id INT NULL;
 // Show online user only to Administrators
 //$_configuration['whoisonline_only_for_admin'] = false;
 
+// Prevent going back to previous questions
+// ALTER TABLE c_quiz ADD COLUMN prevent_backwards INT DEFAULT 0;
+//$_configuration['quiz_prevent_backwards_move'] = false;
+
 // KEEP THIS AT THE END
 // -------- Custom DB changes
 // Add user activation by confirmation email