diff --git a/public/load_search.php b/public/load_search.php
index 6a08d8e520..839072987b 100644
--- a/public/load_search.php
+++ b/public/load_search.php
@@ -54,7 +54,7 @@ $(function() {
 api_block_anonymous_users();
 $allowToSee = api_is_drh() || api_is_student_boss() || api_is_platform_admin();
 
-if ($allowToSee === false) {
+if (false === $allowToSee) {
     api_not_allowed(true);
 }
 $userId = api_get_user_id();
@@ -160,7 +160,7 @@ if (!empty($items)) {
     /** @var ExtraFieldSavedSearch $item */
     foreach ($items as $item) {
         $variable = 'extra_'.$item->getField()->getVariable();
-        if ($item->getField()->getFieldType() == ExtraField::FIELD_TYPE_TAG) {
+        if (ExtraField::FIELD_TYPE_TAG == $item->getField()->getFieldType()) {
             $tagsData[$variable] = $item->getValue();
         }
         $defaults[$variable] = $item->getValue();
@@ -333,13 +333,13 @@ if (isset($_POST) && !empty($_POST)) {
     Session::write('search_using_3', $searchChecked3);
 } else {
     $searchChecked1 = Session::read('search_using_1');
-    $searchChecked1 = $searchChecked1 === null ? 'checked' : $searchChecked1;
+    $searchChecked1 = null === $searchChecked1 ? 'checked' : $searchChecked1;
 
     $searchChecked2 = Session::read('search_using_2');
-    $searchChecked2 = $searchChecked2 === null ? 'checked' : $searchChecked2;
+    $searchChecked2 = null === $searchChecked2 ? 'checked' : $searchChecked2;
 
     $searchChecked3 = Session::read('search_using_3');
-    $searchChecked3 = $searchChecked3 === null ? 'checked' : $searchChecked3;
+    $searchChecked3 = null === $searchChecked3 ? 'checked' : $searchChecked3;
 }
 
 $form->addHtml('<div class="panel panel-default">');
@@ -610,7 +610,7 @@ if ($formSearch->validate()) {
 // Search filter
 $filters = [];
 foreach ($defaults as $key => $value) {
-    if (substr($key, 0, 6) != 'extra_' && substr($key, 0, 7) != '_extra_') {
+    if ('extra_' != substr($key, 0, 6) && '_extra_' != substr($key, 0, 7)) {
         continue;
     }
     if (!empty($value)) {
@@ -671,7 +671,7 @@ if ($form->validate()) {
     if ($search) {
         // Parse params.
         foreach ($params as $key => $value) {
-            if (substr($key, 0, 6) != 'extra_' && substr($key, 0, 7) != '_extra_') {
+            if ('extra_' != substr($key, 0, 6) && '_extra_' != substr($key, 0, 7)) {
                 continue;
             }
             if (!empty($value)) {
@@ -746,7 +746,7 @@ if ($form->validate()) {
 
         foreach ($userData as $key => $value) {
             $found = strpos($key, '__persist__');
-            if ($found === false) {
+            if (false === $found) {
                 continue;
             }
         }
@@ -756,7 +756,7 @@ if ($form->validate()) {
         ) {
             $wantStage = $userData['extra_filiere_want_stage']['extra_filiere_want_stage'];
 
-            if ($wantStage === 'yes') {
+            if ('yes' === $wantStage) {
                 if (isset($userData['extra_filiere_user'])) {
                     $userData['extra_filiere'] = [];
                     $userData['extra_filiere']['extra_filiere'] = $userData['extra_filiere_user']['extra_filiere_user'];
@@ -766,7 +766,7 @@ if ($form->validate()) {
 
         // save in ExtraFieldSavedSearch.
         foreach ($userData as $key => $value) {
-            if (substr($key, 0, 6) != 'extra_' && substr($key, 0, 7) != '_extra_') {
+            if ('extra_' != substr($key, 0, 6) && '_extra_' != substr($key, 0, 7)) {
                 continue;
             }
 
@@ -859,7 +859,7 @@ if (!empty($filterToSend)) {
         $userEndDatePlus = api_get_utc_datetime(substr($userEndDatePlus, 0, 11).'23:59:59');
 
         // Special OFAJ date logic
-        if ($userEndDate == '') {
+        if ('' == $userEndDate) {
             $sql = " AND (
                 (s.access_start_date >= '$userStartDateMinus') OR
                 ((s.access_start_date = '' OR s.access_start_date IS NULL) AND (s.access_end_date = '' OR s.access_end_date IS NULL))
@@ -983,7 +983,7 @@ if (!empty($filterToSend)) {
 
         if ($deleteFiliere) {
             foreach ($filterToSend['rules'] as &$filterItem) {
-                if (isset($filterItem['field']) && $filterItem['field'] == 'extra_filiere') {
+                if (isset($filterItem['field']) && 'extra_filiere' == $filterItem['field']) {
                     $filterItem = [];
                 }
             }
diff --git a/public/main/inc/lib/AnnouncementManager.php b/public/main/inc/lib/AnnouncementManager.php
index b947953367..4ed264f0c1 100644
--- a/public/main/inc/lib/AnnouncementManager.php
+++ b/public/main/inc/lib/AnnouncementManager.php
@@ -9,7 +9,6 @@ use Chamilo\CoreBundle\Framework\Container;
 use Chamilo\CoreBundle\Security\Authorization\Voter\ResourceNodeVoter;
 use Chamilo\CourseBundle\Entity\CAnnouncement;
 use Chamilo\CourseBundle\Entity\CAnnouncementAttachment;
-use Chamilo\CourseBundle\Entity\CCalendarEvent;
 
 /**
  * Include file with functions for the announcements module.
diff --git a/public/main/webservices/cm_webservice_inbox.php b/public/main/webservices/cm_webservice_inbox.php
index 6b54502e8c..e2c8233f68 100644
--- a/public/main/webservices/cm_webservice_inbox.php
+++ b/public/main/webservices/cm_webservice_inbox.php
@@ -19,8 +19,8 @@ class WSCMInbox extends WSCM
             $user_id = UserManager::get_user_id_from_username($username);
             $condition_msg_status = ' msg_status = 1 ';
 
-            $sql_query = "SELECT COUNT(*) as number_messages 
-                          FROM $table_message 
+            $sql_query = "SELECT COUNT(*) as number_messages
+                          FROM $table_message
                           WHERE $condition_msg_status AND user_receiver_id=".$user_id;
 
             $sql_result = Database::query($sql_query);
@@ -113,8 +113,8 @@ class WSCMInbox extends WSCM
             $user_id = UserManager::get_user_id_from_username($username);
 
             $table_message = Database::get_main_table(TABLE_MESSAGE);
-            $sql_query = "SELECT id FROM $table_message 
-                          WHERE user_sender_id=".$user_id." AND msg_status=".MESSAGE_STATUS_OUTBOX." 					 
+            $sql_query = "SELECT id FROM $table_message
+                          WHERE user_sender_id=".$user_id." AND msg_status=".MESSAGE_STATUS_OUTBOX."
                           ORDER BY send_date
                           LIMIT $from,$number_of_items";