diff --git a/main/gradebook/lib/fe/displaygradebook.php b/main/gradebook/lib/fe/displaygradebook.php
index 924f9681cf..1426b6f253 100755
--- a/main/gradebook/lib/fe/displaygradebook.php
+++ b/main/gradebook/lib/fe/displaygradebook.php
@@ -61,7 +61,7 @@ class DisplayGradebook
             $visible = get_lang('No');
         }
 
-        $scoredisplay = ScoreDisplay :: instance();
+        $scoredisplay = ScoreDisplay::instance();
         $student_score = '';
         $average = '';
         if (($evalobj->has_results())) {
@@ -264,7 +264,7 @@ class DisplayGradebook
             /** @var Category $category */
             $category = $catcourse[0];
             $main_weight = $category->get_weight();
-            $scoredisplay = ScoreDisplay :: instance();
+            $scoredisplay = ScoreDisplay::instance();
             $allevals = $category->get_evaluations($userId, true);
             $alllinks = $category->get_links($userId, true);
             $allEvalsLinks = array_merge($allevals, $alllinks);
@@ -295,7 +295,7 @@ class DisplayGradebook
                 $scoreinfo .= '<strong>' . sprintf(get_lang('TotalX'), $scorecourse_display . $aditionalButtons). '</strong>';
 
             }
-            Display :: display_normal_message($scoreinfo, false);
+            Display::display_normal_message($scoreinfo, false);
         }
 
         // show navigation tree and buttons?
@@ -308,7 +308,7 @@ class DisplayGradebook
             }
             $header .= '<td>' . get_lang('CurrentCategory') . '</td>' .
                     '<td><form name="selector"><select name="selectcat" onchange="document.selector.submit()">';
-            $cats = Category :: load();
+            $cats = Category::load();
 
             $tree = $cats[0]->get_tree();
             unset($cats);
@@ -366,7 +366,7 @@ class DisplayGradebook
                 if ($show_add_link && !$message_resource) {
                     $actionsLeft .= '<a href="gradebook_add_eval.php?' . $my_api_cidreq . '&selectcat=' . $catobj->get_id() . '" >' .
                         Display::return_icon('new_evaluation.png', get_lang('NewEvaluation'), '', ICON_SIZE_MEDIUM) . '</a>';
-                    $cats = Category :: load($selectcat);
+                    $cats = Category::load($selectcat);
 
                     if ($cats[0]->get_course_code() != null && !$message_resource) {
                         $actionsLeft .= '<a href="gradebook_add_link.php?' . $my_api_cidreq . '&selectcat=' . $catobj->get_id() . '">' .
@@ -477,18 +477,18 @@ class DisplayGradebook
         //student
         if (!$is_course_admin) {
             $user = api_get_user_info(api_get_user_id());
-            $catcourse = Category :: load($catobj->get_id());
-            $scoredisplay = ScoreDisplay :: instance();
+            $catcourse = Category::load($catobj->get_id());
+            $scoredisplay = ScoreDisplay::instance();
             $scorecourse = $catcourse[0]->calc_score(api_get_user_id());
             $scorecourse_display = (isset($scorecourse) ? $scoredisplay->display_score($scorecourse, SCORE_AVERAGE) : get_lang('NoResultsAvailable'));
-            $cattotal = Category :: load(0);
+            $cattotal = Category::load(0);
             $scoretotal = $cattotal[0]->calc_score(api_get_user_id());
             $scoretotal_display = (isset($scoretotal) ? $scoredisplay->display_score($scoretotal, SCORE_PERCENT) : get_lang('NoResultsAvailable'));
             $scoreinfo = get_lang('StatsStudent') . ' :<b> ' . $user['complete_name']. '</b><br />';
             if ((!$catobj->get_id() == '0') && (!isset($_GET['studentoverview'])) && (!isset($_GET['search'])))
                 $scoreinfo.= '<br />' . get_lang('TotalForThisCategory') . ' : <b>' . $scorecourse_display . '</b>';
             $scoreinfo.= '<br />' . get_lang('Total') . ' : <b>' . $scoretotal_display . '</b>';
-            Display :: display_normal_message($scoreinfo, false);
+            Display::display_normal_message($scoreinfo, false);
         }
         // show navigation tree and buttons?
         $header = '<div class="actions">';
@@ -517,8 +517,8 @@ class DisplayGradebook
             return '';
         }
 
-        $catcourse = Category :: load($categoryId);
-        $scoredisplay = ScoreDisplay :: instance();
+        $catcourse = Category::load($categoryId);
+        $scoredisplay = ScoreDisplay::instance();
 
         // generating the total score for a course
         $allevals = $catcourse[0]->get_evaluations($userId, true, api_get_course_id());
diff --git a/main/gradebook/lib/fe/evalform.class.php b/main/gradebook/lib/fe/evalform.class.php
index 8cc17acba2..8f8f6bb9d4 100755
--- a/main/gradebook/lib/fe/evalform.class.php
+++ b/main/gradebook/lib/fe/evalform.class.php
@@ -53,25 +53,25 @@ class EvalForm extends FormValidator
             $this->extra = $extra1;
         }
         switch ($form_type) {
-            case self :: TYPE_EDIT:
+            case self::TYPE_EDIT:
                 $this->build_editing_form();
                 break;
-            case self :: TYPE_ADD:
+            case self::TYPE_ADD:
                 $this->build_add_form();
                 break;
-            case self :: TYPE_MOVE:
+            case self::TYPE_MOVE:
                 $this->build_editing_form();
                 break;
-            case self :: TYPE_RESULT_ADD:
+            case self::TYPE_RESULT_ADD:
                 $this->build_result_add_form();
                 break;
-            case self :: TYPE_RESULT_EDIT:
+            case self::TYPE_RESULT_EDIT:
                 $this->build_result_edit_form();
                 break;
-            case self :: TYPE_ALL_RESULTS_EDIT:
+            case self::TYPE_ALL_RESULTS_EDIT:
                 $this->build_all_results_edit_form();
                 break;
-            case self :: TYPE_ADD_USERS_TO_EVAL:
+            case self::TYPE_ADD_USERS_TO_EVAL:
                 $this->build_add_user_to_eval();
                 break;
         }
@@ -398,12 +398,12 @@ class EvalForm extends FormValidator
      */
     protected function build_editing_form()
     {
-        $parent_cat = Category :: load($this->evaluation_object->get_category_id());
+        $parent_cat = Category::load($this->evaluation_object->get_category_id());
         //@TODO $weight_mask is replaced?
         if ($parent_cat[0]->get_parent_id() == 0) {
             $weight_mask = $this->evaluation_object->get_weight();
         } else {
-            $cat = Category :: load($parent_cat[0]->get_parent_id());
+            $cat = Category::load($parent_cat[0]->get_parent_id());
             $global_weight = $cat[0]->get_weight();
             $weight_mask = $global_weight * $this->evaluation_object->get_weight() / $parent_cat[0]->get_weight();
         }
@@ -565,12 +565,12 @@ class EvalForm extends FormValidator
 
     function display()
     {
-        parent :: display();
+        parent::display();
     }
 
     function setDefaults($defaults = array(), $filter = null)
     {
-        parent :: setDefaults($defaults, $filter);
+        parent::setDefaults($defaults, $filter);
     }
 
     /**
@@ -586,7 +586,7 @@ class EvalForm extends FormValidator
         $opendocurl_end = '';
         // evaluation's origin is a link
         if ($this->evaluation_object->get_category_id() < 0) {
-            $link = LinkFactory :: get_evaluation_link($this->evaluation_object->get_id());
+            $link = LinkFactory::get_evaluation_link($this->evaluation_object->get_id());
             $doc_url = $link->get_view_url($id);
             if ($doc_url != null) {
                 $opendocurl_start .= '<a href="' . $doc_url . '" target="_blank">';
diff --git a/main/gradebook/lib/fe/linkaddeditform.class.php b/main/gradebook/lib/fe/linkaddeditform.class.php
index 2fe4378749..56ec66d835 100755
--- a/main/gradebook/lib/fe/linkaddeditform.class.php
+++ b/main/gradebook/lib/fe/linkaddeditform.class.php
@@ -25,7 +25,7 @@ class LinkAddEditForm extends FormValidator
         $form_name,
         $action = null
     ) {
-        parent :: __construct($form_name, 'post', $action);
+        parent::__construct($form_name, 'post', $action);
 
         // set or create link object
         if (isset($link_object)) {
@@ -44,7 +44,7 @@ class LinkAddEditForm extends FormValidator
         }
 
         // ELEMENT: name
-        if ($form_type == self :: TYPE_ADD || $link->is_allowed_to_change_name()) {
+        if ($form_type == self::TYPE_ADD || $link->is_allowed_to_change_name()) {
             if ($link->needs_name_and_description()) {
                 $this->addText('name', get_lang('Name'), true, array('size'=>'40', 'maxlength'=>'40'));
             } else {
@@ -119,12 +119,12 @@ class LinkAddEditForm extends FormValidator
 
         $this->addElement('hidden', 'weight');
 
-        if ($form_type == self :: TYPE_EDIT) {
-            $parent_cat = Category :: load($link->get_category_id());
+        if ($form_type == self::TYPE_EDIT) {
+            $parent_cat = Category::load($link->get_category_id());
             if ($parent_cat[0]->get_parent_id() == 0) {
                 $values['weight'] = $link->get_weight();
             } else {
-                $cat = Category :: load($parent_cat[0]->get_parent_id());
+                $cat = Category::load($parent_cat[0]->get_parent_id());
                 //$global_weight = $cat[0]->get_weight();
                 //$values['weight'] = $link->get_weight()/$parent_cat[0]->get_weight()*$global_weight;
                 //var_dump($global_weight, $link->get_weight(), $parent_cat[0]->get_weight());
@@ -138,7 +138,7 @@ class LinkAddEditForm extends FormValidator
         }
         // ELEMENT: max
         if ($link->needs_max()) {
-            if ($form_type == self :: TYPE_EDIT && $link->has_results()) {
+            if ($form_type == self::TYPE_EDIT && $link->has_results()) {
                 $this->addText(
                     'max',
                     get_lang('QualificationNumeric'),
@@ -154,7 +154,7 @@ class LinkAddEditForm extends FormValidator
                 $this->addRule('max', get_lang('OnlyNumbers'), 'numeric');
                 $this->addRule('max', get_lang('NegativeValue'), 'compare', '>=');
             }
-            if ($form_type == self :: TYPE_EDIT) {
+            if ($form_type == self::TYPE_EDIT) {
                 $defaults['max'] = $link->get_max();
             }
         }
@@ -167,30 +167,30 @@ class LinkAddEditForm extends FormValidator
                 get_lang('Description'),
                 array('rows' => '3', 'cols' => '34')
             );
-            if ($form_type == self :: TYPE_EDIT) {
+            if ($form_type == self::TYPE_EDIT) {
                 $defaults['description'] = $link->get_description();
             }
         }
 
         // ELEMENT: visible
-        $visible = ($form_type == self :: TYPE_EDIT && $link->is_visible()) ? '1' : '0';
+        $visible = ($form_type == self::TYPE_EDIT && $link->is_visible()) ? '1' : '0';
         $this->addElement('checkbox', 'visible', null, get_lang('Visible'), $visible);
-        if ($form_type == self :: TYPE_EDIT) {
+        if ($form_type == self::TYPE_EDIT) {
             $defaults['visible'] = $link->is_visible();
         }
 
         // ELEMENT: add results
-        if ($form_type == self :: TYPE_ADD && $link->needs_results()) {
+        if ($form_type == self::TYPE_ADD && $link->needs_results()) {
             $this->addElement('checkbox', 'addresult', get_lang('AddResult'));
         }
         // submit button
-        if ($form_type == self :: TYPE_ADD) {
+        if ($form_type == self::TYPE_ADD) {
             $this->addButtonCreate(get_lang('CreateLink'));
         } else {
             $this->addButtonUpdate(get_lang('LinkMod'));
         }
 
-        if ($form_type == self :: TYPE_ADD) {
+        if ($form_type == self::TYPE_ADD) {
             $setting = api_get_setting('tool_visible_by_default_at_creation');
             $visibility_default = 1;
             if (isset($setting['gradebook']) && $setting['gradebook'] == 'false') {
diff --git a/main/gradebook/lib/fe/usertable.class.php b/main/gradebook/lib/fe/usertable.class.php
index 4e7609ff63..b2c257dfe4 100755
--- a/main/gradebook/lib/fe/usertable.class.php
+++ b/main/gradebook/lib/fe/usertable.class.php
@@ -18,7 +18,7 @@ class UserTable extends SortableTable
      */
     public function __construct($userid, $evals = array(), $links = array(), $addparams = null)
     {
-        parent :: __construct('userlist', null, null, 0);
+        parent::__construct('userlist', null, null, 0);
         $this->userid = $userid;
         $this->datagen = new UserDataGenerator($userid, $evals, $links);
         if (isset($addparams)) {
@@ -32,7 +32,7 @@ class UserTable extends SortableTable
         $this->set_header($column++, get_lang('EvaluationAverage'));
         $this->set_header($column++, get_lang('Result'));
 
-        $scoredisplay = ScoreDisplay :: instance();
+        $scoredisplay = ScoreDisplay::instance();
         if ($scoredisplay->is_custom()) {
             $this->set_header($column++, get_lang('Display'));
         }
@@ -51,37 +51,37 @@ class UserTable extends SortableTable
      */
     public function get_table_data($from = 1, $per_page = null, $column = null, $direction = null, $sort = null)
     {
-        $scoredisplay = ScoreDisplay :: instance();
+        $scoredisplay = ScoreDisplay::instance();
 
         // determine sorting type
         switch ($this->column) {
             // Type
             case 0:
-                $sorting = UserDataGenerator :: UDG_SORT_TYPE;
+                $sorting = UserDataGenerator::UDG_SORT_TYPE;
                 break;
             case 1:
-                $sorting = UserDataGenerator :: UDG_SORT_NAME;
+                $sorting = UserDataGenerator::UDG_SORT_NAME;
                 break;
             case 2:
-                $sorting = UserDataGenerator :: UDG_SORT_COURSE;
+                $sorting = UserDataGenerator::UDG_SORT_COURSE;
                 break;
             case 3:
-                $sorting = UserDataGenerator :: UDG_SORT_CATEGORY;
+                $sorting = UserDataGenerator::UDG_SORT_CATEGORY;
                 break;
             case 4:
-                $sorting = UserDataGenerator :: UDG_SORT_AVERAGE;
+                $sorting = UserDataGenerator::UDG_SORT_AVERAGE;
                 break;
             case 5:
-                $sorting = UserDataGenerator :: UDG_SORT_SCORE;
+                $sorting = UserDataGenerator::UDG_SORT_SCORE;
                 break;
             case 6:
-                $sorting = UserDataGenerator :: UDG_SORT_MASK;
+                $sorting = UserDataGenerator::UDG_SORT_MASK;
                 break;
         }
         if ($this->direction == 'DESC') {
-            $sorting |= UserDataGenerator :: UDG_SORT_DESC;
+            $sorting |= UserDataGenerator::UDG_SORT_DESC;
         } else {
-            $sorting |= UserDataGenerator :: UDG_SORT_ASC;
+            $sorting |= UserDataGenerator::UDG_SORT_ASC;
         }
         $data_array = $this->datagen->get_data($sorting, $from, $this->per_page);
         // generate the data to display
diff --git a/main/inc/lib/TicketManager.php b/main/inc/lib/TicketManager.php
index 993c6d4a52..a47634e96e 100644
--- a/main/inc/lib/TicketManager.php
+++ b/main/inc/lib/TicketManager.php
@@ -322,7 +322,7 @@ class TicketManager
 
         if (!empty($category_id)) {
             if (empty($assignedUserId)) {
-                $usersInCategory = TicketManager::getUsersInCategory($category_id);
+                $usersInCategory = self::getUsersInCategory($category_id);
                 if (!empty($usersInCategory) && count($usersInCategory) > 0) {
                     $userCategoryInfo = $usersInCategory[0];
                     if (isset($userCategoryInfo['user_id'])) {
@@ -481,7 +481,7 @@ class TicketManager
                     $admins = UserManager::get_all_administrators();
                     foreach ($admins as $userId => $data) {
                         if ($data['active']) {
-                            TicketManager::send_message_simple(
+                            self::send_message_simple(
                                 $userId,
                                 $warningSubject,
                                 $helpDeskMessage
@@ -490,13 +490,13 @@ class TicketManager
                     }
                 }
             } else {
-                $categoryInfo = TicketManager::getCategory($category_id);
-                $usersInCategory = TicketManager::getUsersInCategory($category_id);
+                $categoryInfo = self::getCategory($category_id);
+                $usersInCategory = self::getUsersInCategory($category_id);
 
                 $message = '<h2>'.get_lang('TicketInformation').'</h2><br />'.$helpDeskMessage;
 
                 if (api_get_setting('ticket_warn_admin_no_user_in_category') === 'true') {
-                    $usersInCategory = TicketManager::getUsersInCategory($category_id);
+                    $usersInCategory = self::getUsersInCategory($category_id);
                     if (empty($usersInCategory)) {
                         $subject = sprintf(
                             get_lang('WarningCategoryXDoesntHaveUsers'),
@@ -516,7 +516,7 @@ class TicketManager
                             $admins = UserManager::get_all_administrators();
                             foreach ($admins as $userId => $data) {
                                 if ($data['active']) {
-                                    TicketManager::sendNotification(
+                                    self::sendNotification(
                                         $ticketId,
                                         $subject,
                                         $message,
@@ -534,7 +534,7 @@ class TicketManager
                 if (!empty($usersInCategory)) {
                     foreach ($usersInCategory as $data) {
                         if ($data['user_id']) {
-                            TicketManager::sendNotification(
+                            self::sendNotification(
                                 $ticketId,
                                 $subject,
                                 $message,
@@ -554,7 +554,7 @@ class TicketManager
                 );
             }
 
-            TicketManager::sendNotification(
+            self::sendNotification(
                 $ticketId,
                 $titleCreated,
                 $helpDeskMessage
@@ -713,7 +713,7 @@ class TicketManager
         $file_name = $file_attach['name'];
         $table_support_message_attachments = Database::get_main_table(TABLE_TICKET_MESSAGE_ATTACHMENTS);
         if (!filter_extension($new_file_name)) {
-            Display :: display_error_message(
+            Display::display_error_message(
                 get_lang('UplUnableToSaveFileFilteredExtension')
             );
         } else {
@@ -885,7 +885,7 @@ class TicketManager
                 $sql .= " AND ticket.source = '$keyword_source' ";
             }
             if ($keyword_course != '') {
-                $course_table = Database :: get_main_table(TABLE_MAIN_COURSE);
+                $course_table = Database::get_main_table(TABLE_MAIN_COURSE);
                 $sql .= " AND ticket.course_id IN ( 
                          SELECT id FROM $course_table
                          WHERE (
@@ -1150,7 +1150,7 @@ class TicketManager
                 $sql .= " AND ticket.priority_id = '$keyword_priority' ";
             }
             if ($keyword_course != '') {
-                $course_table = Database :: get_main_table(TABLE_MAIN_COURSE);
+                $course_table = Database::get_main_table(TABLE_MAIN_COURSE);
                 $sql .= " AND ticket.course_id IN ( ";
                 $sql .= "SELECT id
                          FROM $course_table
@@ -1734,7 +1734,7 @@ class TicketManager
                 $sql .= " AND ticket.priority_id = '$keyword_priority' ";
             }
             if ($keyword_course != '') {
-                $course_table = Database :: get_main_table(TABLE_MAIN_COURSE);
+                $course_table = Database::get_main_table(TABLE_MAIN_COURSE);
                 $sql .= " AND ticket.course_id IN ( ";
                 $sql .= "SELECT id
                          FROM $course_table
diff --git a/main/inc/lib/blog.lib.php b/main/inc/lib/blog.lib.php
index 9340c323d7..0af1ce66bf 100755
--- a/main/inc/lib/blog.lib.php
+++ b/main/inc/lib/blog.lib.php
@@ -175,7 +175,7 @@ class Blog
             }
 
             // Subscribe the teacher to this blog
-            Blog::subscribeUser($this_blog_id, $_user['user_id']);
+            self::subscribeUser($this_blog_id, $_user['user_id']);
         }
     }
 
@@ -604,7 +604,7 @@ class Blog
 
         // Delete them recursively
         while ($comment = Database::fetch_array($result)) {
-            Blog::deleteComment($blog_id, $post_id, $comment['comment_id']);
+            self::deleteComment($blog_id, $post_id, $comment['comment_id']);
         }
 
         // Finally, delete the selected comment to
@@ -939,7 +939,7 @@ class Blog
         $query_string = '('.implode('OR', $query_string).')';
 
         // Display the posts
-        return Blog::getPosts($blog_id, $query_string);
+        return self::getPosts($blog_id, $query_string);
     }
 
     /**
@@ -987,7 +987,7 @@ class Blog
                 $blog_post_comments = Database::fetch_array($tmp);
 
                 $fileArray = self::getBlogAttachments($blog_id, $blog_post['post_id'], 0);
-                $scoreRanking = Blog::displayRating(
+                $scoreRanking = self::displayRating(
                     'post',
                     $blog_id,
                     $blog_post['post_id']
@@ -1040,7 +1040,7 @@ class Blog
         //$date_output = api_format_date($date_output, DATE_FORMAT_LONG);
         // Display the posts
         //echo '<span class="blogpost_title">' . get_lang('PostsOf') . ': ' . $date_output . '</span>';
-        $list = Blog::getPosts($blog_id, $query_string);
+        $list = self::getPosts($blog_id, $query_string);
 
         return $list;
     }
@@ -1088,11 +1088,11 @@ class Blog
 
         // Display comments if there are any
         if ($blog_post_comments['number_of_comments'] > 0) {
-            $listComments = Blog::getThreadedComments(0, 0, $blog_id, $post_id, $task_id);
+            $listComments = self::getThreadedComments(0, 0, $blog_id, $post_id, $task_id);
         }
         // Display comment form
         if (api_is_allowed('BLOG_'.$blog_id, 'article_comments_add')) {
-            $formComments = Blog::displayCommentCreateForm($blog_id, $post_id, $blog_post['title'], false);
+            $formComments = self::displayCommentCreateForm($blog_id, $post_id, $blog_post['title'], false);
         }
         // Prepare data
         $fileArray = self::getBlogAttachments($blog_id, $post_id);
@@ -1115,7 +1115,7 @@ class Blog
             $blogActions .= Display::return_icon('delete.png', get_lang('Delete'), null, ICON_SIZE_TINY);
             $blogActions .= '</a>';
         }
-        $scoreRanking = Blog::displayRating('post', $blog_id, $post_id);
+        $scoreRanking = self::displayRating('post', $blog_id, $post_id);
         $article = [
             'id_blog' => $blog_post['blog_id'],
             'c_id' => $blog_post['c_id'],
@@ -1135,7 +1135,7 @@ class Blog
             'actions' => $blogActions,
             'score_ranking' => (int)$scoreRanking,
             'frm_rating' => api_is_allowed('BLOG_'.$blog_id, 'article_rate')
-                ? Blog::displayRatingCreateForm('post', $blog_id, $post_id)
+                ? self::displayRatingCreateForm('post', $blog_id, $post_id)
                 : null
         ];
 
@@ -1212,7 +1212,7 @@ class Blog
                 $commentActions .= '</a>';
             }
             if (api_is_allowed('BLOG_'.$blog_id, 'article_comments_rate')) {
-                $ratingSelect = Blog::displayRatingCreateForm(
+                $ratingSelect = self::displayRatingCreateForm(
                     'comment',
                     $blog_id,
                     $post_id,
@@ -1415,7 +1415,7 @@ class Blog
         if ($form->validate()) {
             $values = $form->exportValues();
 
-            Blog::createComment(
+            self::createComment(
                 $values['title'],
                 $values['comment'],
                 $values['post_file_comment'],
diff --git a/main/inc/lib/display.lib.php b/main/inc/lib/display.lib.php
index 3f6a6cf56f..20e1d4b076 100755
--- a/main/inc/lib/display.lib.php
+++ b/main/inc/lib/display.lib.php
@@ -713,7 +713,7 @@ class Display
      */
     public static function returnIconPath($icon, $size = ICON_SIZE_SMALL)
     {
-        return Display::return_icon($icon, null, null, $size, null, true, false);
+        return self::return_icon($icon, null, null, $size, null, true, false);
     }
 
     /**
@@ -1531,8 +1531,8 @@ class Display
 
             $image = substr($notification['image'], 0, -4).'.png';
 
-            $return .= Display::url(
-                Display::return_icon($image, $label),
+            $return .= self::url(
+                self::return_icon($image, $label),
                 api_get_path(WEB_CODE_PATH).
                 $notification['link'].'&cidReq='.$course_code.
                 '&ref='.$notification['ref'].
@@ -1560,8 +1560,8 @@ class Display
         $output = array();
         $active = false;
         if (!$nosession) {
-            $main_user_table = Database :: get_main_table(TABLE_MAIN_USER);
-            $tbl_session = Database :: get_main_table(TABLE_MAIN_SESSION);
+            $main_user_table = Database::get_main_table(TABLE_MAIN_USER);
+            $tbl_session = Database::get_main_table(TABLE_MAIN_SESSION);
             // Request for the name of the general coach
             $sql ='SELECT tu.lastname, tu.firstname, ts.*
                     FROM '.$tbl_session.' ts
@@ -1729,14 +1729,14 @@ class Display
 		$labels[]= $point_info['user_vote']  ? get_lang('YourVote').' ['.$point_info['user_vote'].']' : get_lang('YourVote'). ' [?] ';
 
 		if (!$add_div_wrapper && api_is_anonymous()) {
-			$labels[]= Display::tag('span', get_lang('LoginToVote'), array('class' => 'error'));
+			$labels[]= self::tag('span', get_lang('LoginToVote'), array('class' => 'error'));
 		}
 
-        $html .= Display::div(implode(' | ', $labels) , array('id' =>  'vote_label_'.$id, 'class' => 'vote_label_info'));
-        $html .= ' '.Display::span(' ', array('id' =>  'vote_label2_'.$id));
+        $html .= self::div(implode(' | ', $labels) , array('id' =>  'vote_label_'.$id, 'class' => 'vote_label_info'));
+        $html .= ' '.self::span(' ', array('id' =>  'vote_label2_'.$id));
 
         if ($add_div_wrapper) {
-			$html = Display::div($html, array('id' => 'rating_wrapper_'.$id));
+			$html = self::div($html, array('id' => 'rating_wrapper_'.$id));
 		}
 
         return $html;
@@ -2045,7 +2045,7 @@ class Display
                 <span class="caret"></span></button>
                 <ul class="dropdown-menu ' . ($alignToRight ? 'dropdown-menu-right' : '') . '">';
         foreach ($elements as $item) {
-            $html .= Display::tag('li', Display::url($item['title'], $item['href']));
+            $html .= self::tag('li', self::url($item['title'], $item['href']));
         }
         $html .= '</ul>
             </div>';
@@ -2225,7 +2225,7 @@ class Display
             $label = ($fixedValue + 1) .' '.chr(97 + $localCounter);
             $link_to_show = $link.$fixedValue.'#questionanchor'.$itemId;
         }
-        $link = Display::url($label.' ', $link_to_show, $linkAttributes);
+        $link = self::url($label.' ', $link_to_show, $linkAttributes);
 
         return  '<li class = "'.$class.'">'.$link.'</li>';
     }
@@ -2548,7 +2548,7 @@ HTML;
                 $html .= '<div class="panel-heading">'.$title.'</div>' . PHP_EOL;
             }
             $html.= '<div class="panel-body">'.$content.'</div>' . PHP_EOL;
-            $html = Display::div($html, $params);
+            $html = self::div($html, $params);
         }
         return $html;
     }
diff --git a/main/inc/lib/events.lib.php b/main/inc/lib/events.lib.php
index 98f2a4bd6c..bbee6018cd 100644
--- a/main/inc/lib/events.lib.php
+++ b/main/inc/lib/events.lib.php
@@ -619,7 +619,7 @@ class Event
             return false;
         }
 
-        $table = Database :: get_main_table(TABLE_STATISTIC_TRACK_E_HOTSPOT);
+        $table = Database::get_main_table(TABLE_STATISTIC_TRACK_E_HOTSPOT);
         if ($updateResults) {
             $params = array(
                 'hotspot_correct' => $correct,
@@ -924,7 +924,7 @@ class Event
      */
     public static function get_attempt_count($user_id, $exerciseId, $lp_id, $lp_item_id, $lp_item_view_id)
     {
-        $stat_table = Database :: get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
+        $stat_table = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
         $user_id = intval($user_id);
         $exerciseId = intval($exerciseId);
         $lp_id = intval($lp_id);
@@ -945,7 +945,7 @@ class Event
 
         $query = Database::query($sql);
         if (Database::num_rows($query) > 0) {
-            $attempt = Database :: fetch_array($query, 'ASSOC');
+            $attempt = Database::fetch_array($query, 'ASSOC');
             return $attempt['count'];
         } else {
             return 0;
@@ -961,7 +961,7 @@ class Event
      */
     public static function get_attempt_count_not_finished($user_id, $exerciseId, $lp_id, $lp_item_id)
     {
-        $stat_table = Database :: get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
+        $stat_table = Database::get_main_table(TABLE_STATISTIC_TRACK_E_EXERCISES);
         $user_id = intval($user_id);
         $exerciseId = intval($exerciseId);
         $lp_id = intval($lp_id);
@@ -981,7 +981,7 @@ class Event
 
         $query = Database::query($sql);
         if (Database::num_rows($query) > 0) {
-            $attempt = Database :: fetch_array($query, 'ASSOC');
+            $attempt = Database::fetch_array($query, 'ASSOC');
             return $attempt['count'];
         } else {
             return 0;
@@ -1081,7 +1081,7 @@ class Event
             Database::query($sql);
         }
 
-        Event::addEvent(
+        self::addEvent(
             LOG_LP_ATTEMPT_DELETE,
             LOG_LP_ID,
             $lp_id,
@@ -1116,7 +1116,7 @@ class Event
                         session_id = $session_id AND
                         status = 'incomplete' ";
             Database::query($sql);
-            Event::addEvent(
+            self::addEvent(
                 LOG_EXERCISE_RESULT_DELETE,
                 LOG_EXERCISE_AND_USER_ID,
                 $exercise_id . '-' . $user_id,
@@ -1630,7 +1630,7 @@ class Event
      */
     public static function get_all_exercises_from_lp($lp_id, $course_id)
     {
-        $lp_item_table = Database :: get_course_table(TABLE_LP_ITEM);
+        $lp_item_table = Database::get_course_table(TABLE_LP_ITEM);
         $course_id = intval($course_id);
         $lp_id = intval($lp_id);
         $sql = "SELECT * FROM $lp_item_table
@@ -1722,7 +1722,7 @@ class Event
                     question_id = $question_id ";
         Database::query($sql);
 
-        Event::addEvent(
+        self::addEvent(
             LOG_QUESTION_RESULT_DELETE,
             LOG_EXERCISE_ATTEMPT_QUESTION_ID,
             $exe_id . '-' . $question_id,
@@ -1759,7 +1759,7 @@ class Event
                     c_id = $courseId AND
                     hotspot_question_id = $question_id ";
         Database::query($sql);
-        Event::addEvent(
+        self::addEvent(
             LOG_QUESTION_RESULT_DELETE,
             LOG_EXERCISE_ATTEMPT_QUESTION_ID,
             $exe_id . '-' . $question_id,
diff --git a/src/Chamilo/CourseBundle/Component/CourseCopy/CourseBuilder.php b/src/Chamilo/CourseBundle/Component/CourseCopy/CourseBuilder.php
index 8b1abd56b8..e18a237f1c 100644
--- a/src/Chamilo/CourseBundle/Component/CourseCopy/CourseBuilder.php
+++ b/src/Chamilo/CourseBundle/Component/CourseCopy/CourseBuilder.php
@@ -432,7 +432,7 @@ class CourseBuilder
         $forum_id = null,
         $only_first_post = false
     ) {
-        $table = Database :: get_course_table(TABLE_FORUM_POST);
+        $table = Database::get_course_table(TABLE_FORUM_POST);
         $sql = "SELECT * FROM $table WHERE c_id = $courseId ";
         if (!empty($thread_id) && !empty($forum_id)) {
             $forum_id = intval($forum_id);
@@ -624,10 +624,10 @@ class CourseBuilder
      */
     public function build_quiz_questions($courseId = 0)
     {
-        $table_qui = Database :: get_course_table(TABLE_QUIZ_TEST);
-        $table_rel = Database :: get_course_table(TABLE_QUIZ_TEST_QUESTION);
-        $table_que = Database :: get_course_table(TABLE_QUIZ_QUESTION);
-        $table_ans = Database :: get_course_table(TABLE_QUIZ_ANSWER);
+        $table_qui = Database::get_course_table(TABLE_QUIZ_TEST);
+        $table_rel = Database::get_course_table(TABLE_QUIZ_TEST_QUESTION);
+        $table_que = Database::get_course_table(TABLE_QUIZ_QUESTION);
+        $table_ans = Database::get_course_table(TABLE_QUIZ_ANSWER);
 
         // Building normal tests.
         $sql = "SELECT * FROM $table_que
@@ -942,8 +942,8 @@ class CourseBuilder
      */
     public function build_survey_questions($courseId)
     {
-        $table_que = Database :: get_course_table(TABLE_SURVEY_QUESTION);
-        $table_opt = Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
+        $table_que = Database::get_course_table(TABLE_SURVEY_QUESTION);
+        $table_opt = Database::get_course_table(TABLE_SURVEY_QUESTION_OPTION);
 
         $sql = 'SELECT * FROM '.$table_que.' WHERE c_id = '.$courseId.'  ';
         $db_result = Database::query($sql);
@@ -1281,7 +1281,7 @@ class CourseBuilder
         $with_base_content = false,
         $id_list = array()
     ) {
-        $table_glossary = Database :: get_course_table(TABLE_GLOSSARY);
+        $table_glossary = Database::get_course_table(TABLE_GLOSSARY);
 
         if (!empty($session_id) && !empty($courseId)) {
             $session_id = intval($session_id);
@@ -1430,9 +1430,9 @@ class CourseBuilder
         $with_base_content = false,
         $id_list = array()
     ) {
-        $table_thematic = Database :: get_course_table(TABLE_THEMATIC);
-        $table_thematic_advance = Database :: get_course_table(TABLE_THEMATIC_ADVANCE);
-        $table_thematic_plan = Database :: get_course_table(TABLE_THEMATIC_PLAN);
+        $table_thematic = Database::get_course_table(TABLE_THEMATIC);
+        $table_thematic_advance = Database::get_course_table(TABLE_THEMATIC_ADVANCE);
+        $table_thematic_plan = Database::get_course_table(TABLE_THEMATIC_PLAN);
 
         $session_id = intval($session_id);
         if ($with_base_content) {
@@ -1503,8 +1503,8 @@ class CourseBuilder
         $with_base_content = false,
         $id_list = array()
     ) {
-        $table_attendance = Database :: get_course_table(TABLE_ATTENDANCE);
-        $table_attendance_calendar = Database :: get_course_table(TABLE_ATTENDANCE_CALENDAR);
+        $table_attendance = Database::get_course_table(TABLE_ATTENDANCE);
+        $table_attendance_calendar = Database::get_course_table(TABLE_ATTENDANCE_CALENDAR);
 
         $sessionCondition = api_get_session_condition($session_id, true, $with_base_content);