diff --git a/core/Api/ApiKeyAPI.class.php b/core/Api/ApiKeyAPI.class.php
index b0ce080..d4fb59c 100644
--- a/core/Api/ApiKeyAPI.class.php
+++ b/core/Api/ApiKeyAPI.class.php
@@ -44,7 +44,7 @@ namespace Api\ApiKey {
       $this->loginRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
 
       if(!parent::execute($values)) {
         return false;
@@ -81,7 +81,7 @@ namespace Api\ApiKey {
       $this->loginRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if(!parent::execute($values)) {
         return false;
       }
@@ -127,7 +127,7 @@ namespace Api\ApiKey {
       $this->loginRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if(!parent::execute($values)) {
         return false;
       }
@@ -162,7 +162,7 @@ namespace Api\ApiKey {
       $this->loginRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if(!parent::execute($values)) {
         return false;
       }
diff --git a/core/Api/ContactAPI.class.php b/core/Api/ContactAPI.class.php
index cb4a4d7..2021fc2 100644
--- a/core/Api/ContactAPI.class.php
+++ b/core/Api/ContactAPI.class.php
@@ -34,7 +34,7 @@ namespace Api\Contact {
       parent::__construct($user, $externalCall, $parameters);
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
diff --git a/core/Api/FileAPI.class.php b/core/Api/FileAPI.class.php
index c63ce26..644c51b 100644
--- a/core/Api/FileAPI.class.php
+++ b/core/Api/FileAPI.class.php
@@ -238,7 +238,7 @@ namespace Api\File {
       $this->csrfTokenRequired = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -292,7 +292,7 @@ namespace Api\File {
       $this->loginRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -316,7 +316,7 @@ namespace Api\File {
       $this->csrfTokenRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -360,7 +360,7 @@ namespace Api\File {
       $this->csrfTokenRequired = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -407,7 +407,7 @@ namespace Api\File {
       $this->csrfTokenRequired = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -450,7 +450,7 @@ namespace Api\File {
       $this->loginRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -482,7 +482,7 @@ namespace Api\File {
       ));
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -551,7 +551,7 @@ namespace Api\File {
       $this->loginRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -653,7 +653,7 @@ namespace Api\File {
       $this->csrfTokenRequired = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -826,7 +826,7 @@ namespace Api\File {
       $this->csrfTokenRequired = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -891,7 +891,7 @@ namespace Api\File {
       $this->csrfTokenRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -946,7 +946,7 @@ namespace Api\File {
       $this->csrfTokenRequired = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -1017,7 +1017,7 @@ namespace Api\File {
       $this->csrfTokenRequired = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
diff --git a/core/Api/GroupsAPI.class.php b/core/Api/GroupsAPI.class.php
index 3a81581..5b7a5f2 100644
--- a/core/Api/GroupsAPI.class.php
+++ b/core/Api/GroupsAPI.class.php
@@ -54,7 +54,7 @@ namespace Api\Groups {
       return $this->success;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if(!parent::execute($values)) {
         return false;
       }
@@ -116,7 +116,7 @@ namespace Api\Groups {
       ));
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -162,7 +162,7 @@ namespace Api\Groups {
       ));
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
diff --git a/core/Api/LanguageAPI.class.php b/core/Api/LanguageAPI.class.php
index 89d6487..e61165e 100644
--- a/core/Api/LanguageAPI.class.php
+++ b/core/Api/LanguageAPI.class.php
@@ -23,7 +23,7 @@ namespace Api\Language {
       parent::__construct($user, $externalCall, array());
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if(!parent::execute($values)) {
         return false;
       }
@@ -108,7 +108,7 @@ namespace Api\Language {
       return $this->success;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if(!parent::execute($values)) {
         return false;
       }
diff --git a/core/Api/MailAPI.class.php b/core/Api/MailAPI.class.php
index 13211fa..2dc81ed 100644
--- a/core/Api/MailAPI.class.php
+++ b/core/Api/MailAPI.class.php
@@ -24,7 +24,7 @@ namespace Api\Mail {
       ));
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -77,7 +77,7 @@ namespace Api\Mail {
       return null;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if(!parent::execute($values)) {
         return false;
       }
diff --git a/core/Api/NotificationsAPI.class.php b/core/Api/NotificationsAPI.class.php
index 8b12b10..123523b 100644
--- a/core/Api/NotificationsAPI.class.php
+++ b/core/Api/NotificationsAPI.class.php
@@ -107,7 +107,7 @@ namespace Api\Notifications {
       return $this->success;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if(!parent::execute($values)) {
         return false;
       }
@@ -213,7 +213,7 @@ namespace Api\Notifications {
       return $this->success;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if(!parent::execute($values)) {
         return false;
       }
@@ -235,7 +235,7 @@ namespace Api\Notifications {
       $this->loginRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
diff --git a/core/Api/Parameter/ArrayType.class.php b/core/Api/Parameter/ArrayType.class.php
index 77c89e9..7e0e1ff 100644
--- a/core/Api/Parameter/ArrayType.class.php
+++ b/core/Api/Parameter/ArrayType.class.php
@@ -8,14 +8,22 @@ class ArrayType extends Parameter {
   public int $elementType;
   public int $canBeOne;
 
-  public function __construct($name, $elementType = Parameter::TYPE_MIXED, $canBeOne=false, $optional = FALSE, $defaultValue = NULL) {
+  /**
+   * ArrayType constructor.
+   * @param string $name the name of the parameter
+   * @param int $elementType element type inside the array, for example, allow only integer values (Parameter::TYPE_INT)
+   * @param bool $canBeOne true, if a single element can be passed inside the request (e.g. array=1 instead of array[]=1). Will be automatically casted to an array
+   * @param bool $optional true if the parameter is optional
+   * @param array|null $defaultValue the default value to use, if the parameter is not given
+   */
+  public function __construct(string $name, int $elementType = Parameter::TYPE_MIXED, bool $canBeOne = false, bool $optional = FALSE, ?array $defaultValue = NULL) {
     $this->elementType = $elementType;
     $this->elementParameter = new Parameter('', $elementType);
     $this->canBeOne = $canBeOne;
     parent::__construct($name, Parameter::TYPE_ARRAY, $optional, $defaultValue);
   }
 
-  public function parseParam($value) {
+  public function parseParam($value): bool {
     if(!is_array($value)) {
       if (!$this->canBeOne) {
         return false;
@@ -38,12 +46,12 @@ class ArrayType extends Parameter {
     return true;
   }
 
-  public function getTypeName() {
+  public function getTypeName(): string {
     $elementType = $this->elementParameter->getTypeName();
     return parent::getTypeName() . "($elementType)";
   }
 
-  public function toString() {
+  public function toString(): string {
     $typeName = $this->getTypeName();
     $str = "$typeName $this->name";
     $defaultValue = (is_null($this->value) ? 'NULL' : (is_array($this->value) ? '[' . implode(",", $this->value) . ']' : $this->value));
diff --git a/core/Api/Parameter/Parameter.class.php b/core/Api/Parameter/Parameter.class.php
index f58b749..3212538 100644
--- a/core/Api/Parameter/Parameter.class.php
+++ b/core/Api/Parameter/Parameter.class.php
@@ -26,11 +26,11 @@ class Parameter {
 
   public string $name;
   public $value;
-  public $optional;
+  public bool $optional;
   public int $type;
   public string $typeName;
 
-  public function __construct($name, $type, $optional = FALSE, $defaultValue = NULL) {
+  public function __construct(string $name, int $type, bool $optional = FALSE, $defaultValue = NULL) {
     $this->name = $name;
     $this->optional = $optional;
     $this->value = $defaultValue;
@@ -38,11 +38,11 @@ class Parameter {
     $this->typeName = $this->getTypeName();
   }
 
-  public function getTypeName() {
+  public function getTypeName(): string {
     return ($this->type >= 0 && $this->type < count(Parameter::names)) ? Parameter::names[$this->type] : "INVALID";
   }
 
-  public function toString() {
+  public function toString(): string {
     $typeName = Parameter::names[$this->type];
 
     $str = "$typeName $this->name";
@@ -54,7 +54,7 @@ class Parameter {
     return $str;
   }
 
-  public static function parseType($value) {
+  public static function parseType($value): int {
     if(is_array($value))
       return Parameter::TYPE_ARRAY;
     else if(is_numeric($value) && intval($value) == $value)
@@ -77,7 +77,7 @@ class Parameter {
       return Parameter::TYPE_STRING;
   }
 
-  public function parseParam($value) {
+  public function parseParam($value): bool {
     switch($this->type) {
       case Parameter::TYPE_INT:
         if(is_numeric($value) && intval($value) == $value) {
diff --git a/core/Api/Parameter/StringType.class.php b/core/Api/Parameter/StringType.class.php
index dc5bc35..4bca3f0 100644
--- a/core/Api/Parameter/StringType.class.php
+++ b/core/Api/Parameter/StringType.class.php
@@ -5,12 +5,12 @@ namespace Api\Parameter;
 class StringType extends Parameter {
 
   public int $maxLength;
-  public function __construct($name, $maxLength = -1, $optional = FALSE, $defaultValue = NULL) {
+  public function __construct(string $name, int $maxLength = -1, bool $optional = FALSE, ?string $defaultValue = NULL) {
     $this->maxLength = $maxLength;
     parent::__construct($name, Parameter::TYPE_STRING, $optional, $defaultValue);
   }
 
-  public function parseParam($value) {
+  public function parseParam($value): bool {
     if(!is_string($value)) {
       return false;
     }
@@ -23,12 +23,12 @@ class StringType extends Parameter {
     return true;
   }
 
-  public function getTypeName() {
+  public function getTypeName(): string {
     $maxLength = ($this->maxLength > 0 ? "($this->maxLength)" : "");
     return parent::getTypeName() . $maxLength;
   }
 
-  public function toString() {
+  public function toString(): string {
     $typeName = $this->getTypeName();
     $str = "$typeName $this->name";
     $defaultValue = (is_null($this->value) ? 'NULL' : $this->value);
diff --git a/core/Api/PatchSQL.class.php b/core/Api/PatchSQL.class.php
index a985a32..3c12800 100644
--- a/core/Api/PatchSQL.class.php
+++ b/core/Api/PatchSQL.class.php
@@ -16,7 +16,7 @@ class PatchSQL extends Request {
     $this->csrfTokenRequired = false;
   }
 
-  public function execute($values = array()) {
+  public function execute($values = array()): bool {
     if (!parent::execute($values)) {
       return false;
     }
diff --git a/core/Api/PermissionAPI.class.php b/core/Api/PermissionAPI.class.php
index 24ad282..dd91f75 100644
--- a/core/Api/PermissionAPI.class.php
+++ b/core/Api/PermissionAPI.class.php
@@ -35,7 +35,7 @@ namespace Api\Permission {
       $this->isPublic = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -102,7 +102,7 @@ namespace Api\Permission {
       return $this->success;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -147,7 +147,7 @@ namespace Api\Permission {
       ));
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
diff --git a/core/Api/Request.class.php b/core/Api/Request.class.php
index 7576df4..6364f95 100644
--- a/core/Api/Request.class.php
+++ b/core/Api/Request.class.php
@@ -41,33 +41,34 @@ class Request {
 
   protected function forbidMethod($method) {
     if (($key = array_search($method, $this->allowedMethods)) !== false) {
-        unset($this->allowedMethods[$key]);
+      unset($this->allowedMethods[$key]);
     }
   }
 
-  public function parseParams($values) {
+  public function parseParams($values): bool {
 
-    foreach($this->params as $name => $param) {
+    foreach ($this->params as $name => $param) {
       $value = $values[$name] ?? NULL;
 
       $isEmpty = (is_string($value) && strlen($value) === 0) || (is_array($value) && empty($value));
-      if(!$param->optional && (is_null($value) || $isEmpty)) {
+      if (!$param->optional && (is_null($value) || $isEmpty)) {
         return $this->createError("Missing parameter: $name");
       }
 
-      if(!is_null($value) && !$isEmpty) {
-        if(!$param->parseParam($value)) {
+      if (!is_null($value) && !$isEmpty) {
+        if (!$param->parseParam($value)) {
           $value = print_r($value, true);
           return $this->createError("Invalid Type for parameter: $name '$value' (Required: " . $param->getTypeName() . ")");
         }
       }
     }
+
     return true;
   }
 
   public function parseVariableParams($values) {
-    foreach($values as $name => $value) {
-      if(isset($this->params[$name])) continue;
+    foreach ($values as $name => $value) {
+      if (isset($this->params[$name])) continue;
       $type = Parameter\Parameter::parseType($value);
       $param = new Parameter\Parameter($name, $type, true);
       $param->parseParam($value);
@@ -75,19 +76,19 @@ class Request {
     }
   }
 
-  public function execute($values = array()) {
+  public function execute($values = array()): bool {
     $this->params = $this->aDefaultParams;
     $this->success = false;
     $this->result = array();
     $this->lastError = '';
 
-    if($this->user->isLoggedIn()) {
+    if ($this->user->isLoggedIn()) {
       $this->result['logoutIn'] = $this->user->getSession()->getExpiresSeconds();
     }
 
-    if($this->externalCall) {
+    if ($this->externalCall) {
       $values = $_REQUEST;
-      if($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_SERVER["CONTENT_TYPE"]) && in_array("application/json", explode(";", $_SERVER["CONTENT_TYPE"]))) {
+      if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_SERVER["CONTENT_TYPE"]) && in_array("application/json", explode(";", $_SERVER["CONTENT_TYPE"]))) {
         $jsonData = json_decode(file_get_contents('php://input'), true);
         if ($jsonData) {
           $values = array_merge($values, $jsonData);
@@ -99,34 +100,34 @@ class Request {
       }
     }
 
-    if($this->isDisabled) {
+    if ($this->isDisabled) {
       $this->lastError = "This function is currently disabled.";
       return false;
     }
 
-    if($this->externalCall && !$this->isPublic) {
+    if ($this->externalCall && !$this->isPublic) {
       $this->lastError = 'This function is private.';
       header('HTTP 1.1 403 Forbidden');
       return false;
     }
 
-    if(!in_array($_SERVER['REQUEST_METHOD'], $this->allowedMethods)) {
+    if (!in_array($_SERVER['REQUEST_METHOD'], $this->allowedMethods)) {
       $this->lastError = 'This method is not allowed';
       header('HTTP 1.1 405 Method Not Allowed');
       return false;
     }
 
-    if($this->externalCall) {
+    if ($this->externalCall) {
       $apiKeyAuthorized = false;
 
       // Logged in or api key authorized?
       if ($this->loginRequired) {
-        if(isset($values['api_key']) && $this->apiKeyAllowed) {
+        if (isset($values['api_key']) && $this->apiKeyAllowed) {
           $apiKey = $values['api_key'];
           $apiKeyAuthorized = $this->user->authorize($apiKey);
         }
 
-        if(!$this->user->isLoggedIn() && !$apiKeyAuthorized) {
+        if (!$this->user->isLoggedIn() && !$apiKeyAuthorized) {
           $this->lastError = 'You are not logged in.';
           header('HTTP 1.1 401 Unauthorized');
           return false;
@@ -134,7 +135,7 @@ class Request {
       }
 
       // CSRF Token
-      if($this->csrfTokenRequired && $this->user->isLoggedIn()) {
+      if ($this->csrfTokenRequired && $this->user->isLoggedIn()) {
         // csrf token required + external call
         // if it's not a call with API_KEY, check for csrf_token
         if (!isset($values["csrf_token"]) || strcmp($values["csrf_token"], $this->user->getSession()->getCsrfToken()) !== 0) {
@@ -155,13 +156,15 @@ class Request {
       }
     }
 
-    if(!$this->parseParams($values))
+    if (!$this->parseParams($values)) {
       return false;
+    }
 
-    if($this->variableParamCount)
+    if ($this->variableParamCount) {
       $this->parseVariableParams($values);
+    }
 
-    if(!$this->user->getSQL()->isConnected()) {
+    if (!$this->user->getSQL()->isConnected()) {
       $this->lastError = $this->user->getSQL()->getLastError();
       return false;
     }
@@ -171,23 +174,39 @@ class Request {
     return true;
   }
 
-  protected function createError($err) {
+  protected function createError($err): bool {
     $this->success = false;
     $this->lastError = $err;
     return false;
   }
 
   protected function getParam($name) {
-    return isset($this->params[$name]) ? $this->params[$name]->value : NULL;
+    return $this->params[$name] ?? NULL;
   }
 
-  public function isPublic() { return $this->isPublic; }
-  public function getLastError() { return $this->lastError; }
-  public function getResult() { return $this->result; }
-  public function success() { return $this->success; }
-  public function loginRequired() { return $this->loginRequired; }
-  public function isExternalCall() { return $this->externalCall; }
-  public function clearError() { $this->success = true; $this->lastError = ""; }
+  public function isPublic(): bool {
+    return $this->isPublic;
+  }
+
+  public function getLastError(): string {
+    return $this->lastError;
+  }
+
+  public function getResult(): array {
+    return $this->result;
+  }
+
+  public function success(): bool {
+    return $this->success;
+  }
+
+  public function loginRequired(): bool {
+    return $this->loginRequired;
+  }
+
+  public function isExternalCall(): bool {
+    return $this->externalCall;
+  }
 
   private function getMethod() {
     $class = str_replace("\\", "/", get_class($this));
@@ -195,7 +214,7 @@ class Request {
     return $class;
   }
 
-  public function getJsonResult() {
+  public function getJsonResult(): string {
     $this->result['success'] = $this->success;
     $this->result['msg'] = $this->lastError;
     return json_encode($this->result);
diff --git a/core/Api/RoutesAPI.class.php b/core/Api/RoutesAPI.class.php
index ef4c0a2..3247d42 100644
--- a/core/Api/RoutesAPI.class.php
+++ b/core/Api/RoutesAPI.class.php
@@ -34,7 +34,7 @@ namespace Api\Routes {
     parent::__construct($user, $externalCall, array());
   }
 
-  public function execute($values = array()) {
+  public function execute($values = array()): bool {
     if(!parent::execute($values)) {
       return false;
     }
@@ -81,7 +81,7 @@ namespace Api\Routes {
       $this->isPublic = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if(!parent::execute($values)) {
         return false;
       }
@@ -133,7 +133,7 @@ namespace Api\Routes {
       ));
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if(!parent::execute($values)) {
         return false;
       }
diff --git a/core/Api/SettingsAPI.class.php b/core/Api/SettingsAPI.class.php
index cecb991..9ddf4c3 100644
--- a/core/Api/SettingsAPI.class.php
+++ b/core/Api/SettingsAPI.class.php
@@ -29,7 +29,7 @@ namespace Api\Settings {
       ));
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
        if(!parent::execute($values)) {
          return false;
        }
@@ -72,7 +72,7 @@ namespace Api\Settings {
       ));
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
diff --git a/core/Api/Stats.class.php b/core/Api/Stats.class.php
index 3844943..8bb1cb7 100644
--- a/core/Api/Stats.class.php
+++ b/core/Api/Stats.class.php
@@ -66,7 +66,7 @@ class Stats extends Request {
     return ($this->success ? $res[0]["count"] : $this->success);
   }
 
-  public function execute($values = array()) {
+  public function execute($values = array()): bool {
     if(!parent::execute($values)) {
       return false;
     }
diff --git a/core/Api/UserAPI.class.php b/core/Api/UserAPI.class.php
index a759fb9..8083657 100644
--- a/core/Api/UserAPI.class.php
+++ b/core/Api/UserAPI.class.php
@@ -9,11 +9,11 @@ namespace Api {
     protected function userExists(?string $username, ?string $email) {
 
       $conditions = array();
-      if (!is_null($username) && !empty($username)) {
+      if ($username) {
         $conditions[] = new Compare("User.name", $username);
       }
 
-      if (!is_null($email) && !empty($email)) {
+      if ($email) {
         $conditions[] = new Compare("User.email", $email);
       }
 
@@ -152,7 +152,7 @@ namespace Api\User {
       $this->loginRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -229,7 +229,7 @@ namespace Api\User {
       return false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -306,7 +306,7 @@ namespace Api\User {
       ));
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -350,7 +350,7 @@ namespace Api\User {
       $this->csrfTokenRequired = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -377,7 +377,7 @@ namespace Api\User {
       $this->loginRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -469,7 +469,7 @@ namespace Api\User {
       return $this->success;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -533,7 +533,7 @@ namespace Api\User {
       return $this->success;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -586,7 +586,7 @@ namespace Api\User {
       return $this->createError(L('Wrong username or password'));
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -648,7 +648,7 @@ namespace Api\User {
       $this->apiKeyAllowed = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -693,7 +693,7 @@ namespace Api\User {
       return $this->success;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -804,7 +804,7 @@ namespace Api\User {
       return array();
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -847,7 +847,7 @@ namespace Api\User {
       $this->loginRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -945,7 +945,7 @@ namespace Api\User {
       $this->loginRequired = true;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -986,7 +986,7 @@ namespace Api\User {
       $this->csrfTokenRequired = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -1105,7 +1105,7 @@ namespace Api\User {
       return $this->success;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
diff --git a/core/Api/VerifyCaptcha.class.php b/core/Api/VerifyCaptcha.class.php
index 2e41c22..51ae427 100644
--- a/core/Api/VerifyCaptcha.class.php
+++ b/core/Api/VerifyCaptcha.class.php
@@ -16,7 +16,7 @@ class VerifyCaptcha extends Request {
     $this->isPublic = false;
   }
 
-  public function execute($values = array()) {
+  public function execute($values = array()): bool {
      if(!parent::execute($values)) {
        return false;
      }
diff --git a/core/Api/VisitorsAPI.class.php b/core/Api/VisitorsAPI.class.php
index 97f46b1..7614d6f 100644
--- a/core/Api/VisitorsAPI.class.php
+++ b/core/Api/VisitorsAPI.class.php
@@ -27,7 +27,7 @@ namespace Api\Visitors {
       $this->isPublic = false;
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
@@ -75,7 +75,7 @@ namespace Api\Visitors {
       }
     }
 
-    public function execute($values = array()) {
+    public function execute($values = array()): bool {
       if (!parent::execute($values)) {
         return false;
       }
diff --git a/core/Configuration/Configuration.class.php b/core/Configuration/Configuration.class.php
index 6230d75..4763720 100755
--- a/core/Configuration/Configuration.class.php
+++ b/core/Configuration/Configuration.class.php
@@ -15,27 +15,27 @@ class Configuration {
 
     $class = \Configuration\Database::class;
     $path = getClassPath($class, true);
-    if(file_exists($path) && is_readable($path)) {
+    if (file_exists($path) && is_readable($path)) {
       include_once $path;
-      if(class_exists($class)) {
+      if (class_exists($class)) {
         $this->database = new \Configuration\Database();
       }
     }
   }
 
-  public function getDatabase() : ?ConnectionData {
+  public function getDatabase(): ?ConnectionData {
     return $this->database;
   }
 
-  public function getSettings() : Settings {
+  public function getSettings(): Settings {
     return $this->settings;
   }
 
   public function create(string $className, $data) {
     $path = getClassPath("\\Configuration\\$className");
 
-    if($data) {
-      if(is_string($data)) {
+    if ($data) {
+      if (is_string($data)) {
         $key = addslashes($data);
         $code = intendCode(
           "<?php
@@ -50,7 +50,7 @@ class Configuration {
             
           }", false
         );
-      } else if($data instanceof ConnectionData) {
+      } else if ($data instanceof ConnectionData) {
         $superClass = get_class($data);
         $host = addslashes($data->getHost());
         $port = intval($data->getPort());
@@ -58,7 +58,7 @@ class Configuration {
         $password = addslashes($data->getPassword());
 
         $properties = "";
-        foreach($data->getProperties() as $key => $val) {
+        foreach ($data->getProperties() as $key => $val) {
           $key = addslashes($key);
           $val = is_string($val) ? "'" . addslashes($val) . "'" : $val;
           $properties .= "\n\$this->setProperty('$key', $val);";
@@ -86,9 +86,9 @@ class Configuration {
     return @file_put_contents($path, $code);
   }
 
-  public function delete(string $className) {
+  public function delete(string $className): bool {
     $path = getClassPath("\\Configuration\\$className");
-    if(file_exists($path)) {
+    if (file_exists($path)) {
       return unlink($path);
     }
 
diff --git a/core/Configuration/CreateDatabase.class.php b/core/Configuration/CreateDatabase.class.php
index 6567751..5de3e77 100755
--- a/core/Configuration/CreateDatabase.class.php
+++ b/core/Configuration/CreateDatabase.class.php
@@ -11,7 +11,7 @@ class CreateDatabase extends DatabaseScript {
   // NOTE:
   // explicit serial ids removed due to postgres' serial implementation
 
-  public static function createQueries(SQL $sql) {
+  public static function createQueries(SQL $sql): array {
     $queries = array();
 
     // Language
@@ -24,8 +24,8 @@ class CreateDatabase extends DatabaseScript {
       ->unique("name");
 
     $queries[] = $sql->insert("Language", array("code", "name"))
-      ->addRow( "en_US", 'American English')
-      ->addRow( "de_DE", 'Deutsch Standard');
+      ->addRow("en_US", 'American English')
+      ->addRow("de_DE", 'Deutsch Standard');
 
     $queries[] = $sql->createTable("User")
       ->addSerial("uid")
@@ -50,7 +50,7 @@ class CreateDatabase extends DatabaseScript {
       ->addString("browser", 64)
       ->addJson("data", false, '{}')
       ->addBool("stay_logged_in", true)
-      ->addString("csrf_token", 16 )
+      ->addString("csrf_token", 16)
       ->primaryKey("uid", "user_id")
       ->foreignKey("user_id", "User", "uid", new CascadeStrategy());
 
@@ -82,7 +82,7 @@ class CreateDatabase extends DatabaseScript {
 
     $queries[] = $sql->createTable("Notification")
       ->addSerial("uid")
-      ->addEnum("type", array("default","message","warning"), false, "default")
+      ->addEnum("type", array("default", "message", "warning"), false, "default")
       ->addDateTime("created_at", false, $sql->currentTimestamp())
       ->addString("title", 32)
       ->addString("message", 256)
@@ -200,7 +200,7 @@ class CreateDatabase extends DatabaseScript {
     return $queries;
   }
 
-  private static function MessageConfirmEmail() : string {
+  private static function MessageConfirmEmail(): string {
     return "Hello {{username}},<br>" .
       "You recently created an account on {{site_name}}. Please click on the following link to " .
       "confirm your email address and complete your registration. If you haven't registered an " .
@@ -210,7 +210,7 @@ class CreateDatabase extends DatabaseScript {
       "{{site_name}} Administration";
   }
 
-  private static function MessageAcceptInvite() : string {
+  private static function MessageAcceptInvite(): string {
     return "Hello {{username}},<br>" .
       "You were invited to create an account on {{site_name}}. Please click on the following link to " .
       "confirm your email address and complete your registration by choosing a new password. " .
@@ -220,7 +220,7 @@ class CreateDatabase extends DatabaseScript {
       "{{site_name}} Administration";
   }
 
-  private static function MessageResetPassword() : string {
+  private static function MessageResetPassword(): string {
     return "Hello {{username}},<br>" .
       "you requested a password reset on {{site_name}}. Please click on the following link to " .
       "choose a new password. If this request was not intended, you can simply ignore the email. The Link is valid for one hour:<br><br>" .
@@ -233,7 +233,7 @@ class CreateDatabase extends DatabaseScript {
     $patchDirectory = './core/Configuration/Patch/';
     if (file_exists($patchDirectory) && is_dir($patchDirectory)) {
       $scan_arr = scandir($patchDirectory);
-      $files_arr = array_diff($scan_arr, array('.','..'));
+      $files_arr = array_diff($scan_arr, array('.', '..'));
       foreach ($files_arr as $file) {
         $suffix = ".class.php";
         if (endsWith($file, $suffix)) {
@@ -241,7 +241,7 @@ class CreateDatabase extends DatabaseScript {
           $className = "\\Configuration\\Patch\\$className";
           $method = "$className::createQueries";
           $patchQueries = call_user_func($method, $sql);
-          foreach($patchQueries as $query) $queries[] = $query;
+          foreach ($patchQueries as $query) $queries[] = $query;
         }
       }
     }
diff --git a/core/Configuration/Patch/file_api.class.php b/core/Configuration/Patch/file_api.class.php
index 506fdea..2a09cd5 100644
--- a/core/Configuration/Patch/file_api.class.php
+++ b/core/Configuration/Patch/file_api.class.php
@@ -10,7 +10,7 @@ use Driver\SQL\Strategy\UpdateStrategy;
 
 class file_api extends DatabaseScript {
 
-  public static function createQueries(SQL $sql) {
+  public static function createQueries(SQL $sql): array {
 
     $queries = array();
 
diff --git a/core/Configuration/Settings.class.php b/core/Configuration/Settings.class.php
index 27904a5..7a981aa 100644
--- a/core/Configuration/Settings.class.php
+++ b/core/Configuration/Settings.class.php
@@ -11,12 +11,16 @@ use Objects\User;
 
 class Settings {
 
+  //
+  private bool $installationComplete;
+
+  // settings
   private string $siteName;
   private string $baseUrl;
   private string $jwtSecret;
-  private bool $installationComplete;
   private bool $registrationAllowed;
   private bool $recaptchaEnabled;
+  private bool $mailEnabled;
   private string $recaptchaPublicKey;
   private string $recaptchaPrivateKey;
 
@@ -24,11 +28,11 @@ class Settings {
     return $this->jwtSecret;
   }
 
-  public function isInstalled() {
+  public function isInstalled(): bool {
     return $this->installationComplete;
   }
 
-  public static function loadDefaults() : Settings {
+  public static function loadDefaults(): Settings {
     $hostname = $_SERVER["SERVER_NAME"];
     $protocol = getProtocol();
     $jwt = generateRandomString(32);
@@ -42,10 +46,11 @@ class Settings {
     $settings->recaptchaPublicKey = "";
     $settings->recaptchaPrivateKey = "";
     $settings->recaptchaEnabled = false;
+    $settings->mailEnabled = false;
     return $settings;
   }
 
-  public function loadFromDatabase(User $user) {
+  public function loadFromDatabase(User $user): bool {
     $req = new \Api\Settings\Get($user);
     $success = $req->execute();
 
@@ -58,6 +63,7 @@ class Settings {
       $this->recaptchaEnabled = $result["recaptcha_enabled"] ?? $this->recaptchaEnabled;
       $this->recaptchaPublicKey = $result["recaptcha_public_key"] ?? $this->recaptchaPublicKey;
       $this->recaptchaPrivateKey = $result["recaptcha_private_key"] ?? $this->recaptchaPrivateKey;
+      $this->mailEnabled = $result["mail_enabled"] ?? $this->mailEnabled;
 
       if (!isset($result["jwt_secret"])) {
         $req = new \Api\Settings\Set($user);
@@ -81,27 +87,27 @@ class Settings {
       ->addRow("recaptcha_private_key", $this->recaptchaPrivateKey, true, false);
   }
 
-  public function getSiteName() : string {
+  public function getSiteName(): string {
     return $this->siteName;
   }
 
-  public function getBaseUrl() : string {
+  public function getBaseUrl(): string {
     return $this->baseUrl;
   }
 
-  public function isRecaptchaEnabled() : bool {
+  public function isRecaptchaEnabled(): bool {
     return $this->recaptchaEnabled;
   }
 
-  public function getRecaptchaSiteKey() : string {
+  public function getRecaptchaSiteKey(): string {
     return $this->recaptchaPublicKey;
   }
 
-  public function getRecaptchaSecretKey() : string {
+  public function getRecaptchaSecretKey(): string {
     return $this->recaptchaPrivateKey;
   }
 
-  public function isRegistrationAllowed() : bool {
+  public function isRegistrationAllowed(): bool {
     return $this->registrationAllowed;
   }
 }
\ No newline at end of file
diff --git a/core/Documents/Account.class.php b/core/Documents/Account.class.php
index 8b811a6..27c6843 100644
--- a/core/Documents/Account.class.php
+++ b/core/Documents/Account.class.php
@@ -34,7 +34,7 @@ namespace Documents\Account {
       $this->loadFontawesome();
     }
 
-    protected function initMetas() {
+    protected function initMetas(): array {
       return array(
         array('name' => 'viewport', 'content' => 'width=device-width, initial-scale=1.0'),
         array('name' => 'format-detection', 'content' => 'telephone=yes'),
@@ -44,11 +44,11 @@ namespace Documents\Account {
       );
     }
 
-    protected function initRawFields() {
+    protected function initRawFields(): array {
       return array();
     }
 
-    protected function initTitle() {
+    protected function initTitle(): string {
       return "Account";
     }
   }
@@ -59,7 +59,7 @@ namespace Documents\Account {
       parent::__construct($document);
     }
 
-    protected function getContent() {
+    protected function getContent(): string {
 
       $view = $this->getDocument()->getView();
       if ($view === null) {
diff --git a/core/Documents/Admin.class.php b/core/Documents/Admin.class.php
index 662e0da..8056640 100644
--- a/core/Documents/Admin.class.php
+++ b/core/Documents/Admin.class.php
@@ -19,8 +19,6 @@ namespace Documents {
 namespace Documents\Admin {
 
   use Elements\Head;
-  use Elements\Link;
-  use Elements\Script;
 
   class AdminHead extends Head {
 
@@ -32,7 +30,7 @@ namespace Documents\Admin {
       $this->loadFontawesome();
     }
 
-    protected function initMetas() {
+    protected function initMetas(): array {
       return array(
         array('name' => 'viewport', 'content' => 'width=device-width, initial-scale=1.0'),
         array('name' => 'format-detection', 'content' => 'telephone=yes'),
@@ -42,12 +40,12 @@ namespace Documents\Admin {
       );
     }
 
-    protected function initRawFields() {
+    protected function initRawFields(): array {
       return array();
     }
 
-    protected function initTitle() {
-      return "WebBase - Administration";
+    protected function initTitle(): string {
+      return $this->getSiteName() . " - Administration";
     }
   }
 }
\ No newline at end of file
diff --git a/core/Documents/Document404.class.php b/core/Documents/Document404.class.php
index fa97af3..376039b 100644
--- a/core/Documents/Document404.class.php
+++ b/core/Documents/Document404.class.php
@@ -15,7 +15,6 @@ namespace Documents {
 
 namespace Documents\Document404 {
 
-  use Elements\Body;
   use Elements\Head;
   use Elements\SimpleBody;
   use Views\View404;
@@ -29,7 +28,7 @@ namespace Documents\Document404 {
     protected function initSources() {
     }
 
-    protected function initMetas() {
+    protected function initMetas(): array {
       return array(
         array('name' => 'viewport', 'content' => 'width=device-width, initial-scale=1.0'),
         array('name' => 'format-detection', 'content' => 'telephone=yes'),
@@ -39,11 +38,11 @@ namespace Documents\Document404 {
       );
     }
 
-    protected function initRawFields() {
+    protected function initRawFields(): array {
       return array();
     }
 
-    protected function initTitle() {
+    protected function initTitle(): string {
       return "WebBase - Not Found";
     }
   }
@@ -58,7 +57,7 @@ namespace Documents\Document404 {
       http_response_code(404);
     }
 
-    protected function getContent() {
+    protected function getContent(): string {
       return $this->load(View404::class);
     }
   }
diff --git a/core/Documents/Files.class.php b/core/Documents/Files.class.php
index 7927b0d..37db052 100644
--- a/core/Documents/Files.class.php
+++ b/core/Documents/Files.class.php
@@ -28,7 +28,7 @@ namespace Documents\Files {
       $this->loadFontawesome();
     }
 
-    protected function initMetas() {
+    protected function initMetas(): array {
       return array(
         array('name' => 'viewport', 'content' => 'width=device-width, initial-scale=1.0'),
         array('name' => 'format-detection', 'content' => 'telephone=yes'),
@@ -39,11 +39,11 @@ namespace Documents\Files {
       );
     }
 
-    protected function initRawFields() {
+    protected function initRawFields(): array {
       return array();
     }
 
-    protected function initTitle() {
+    protected function initTitle(): string {
       return "File Control Panel";
     }
   }
@@ -54,7 +54,7 @@ namespace Documents\Files {
       parent::__construct($document);
     }
 
-    protected function getContent() {
+    protected function getContent(): string {
       $html = "<noscript>" . $this->createErrorText("Javascript is required for this site to render.") . "</noscript>";
       $html .= "<div id=\"root\"></div>";
       $html .= new Script(Script::MIME_TEXT_JAVASCRIPT, Script::FILES);
diff --git a/core/Documents/Install.class.php b/core/Documents/Install.class.php
index 119db1e..d873da5 100644
--- a/core/Documents/Install.class.php
+++ b/core/Documents/Install.class.php
@@ -41,7 +41,7 @@ namespace Documents\Install {
       $this->addJS(Script::INSTALL);
     }
 
-    protected function initMetas() {
+    protected function initMetas(): array {
       return array(
         array('name' => 'viewport', 'content' => 'width=device-width, initial-scale=1.0'),
         array('name' => 'format-detection', 'content' => 'telephone=yes'),
@@ -51,11 +51,11 @@ namespace Documents\Install {
       );
     }
 
-    protected function initRawFields() {
+    protected function initRawFields(): array {
       return array();
     }
 
-    protected function initTitle() {
+    protected function initTitle(): string {
       return "WebBase - Installation";
     }
 
@@ -88,17 +88,17 @@ namespace Documents\Install {
       $this->steps = array();
     }
 
-    private function getParameter($name) {
-      if(isset($_REQUEST[$name]) && is_string($_REQUEST[$name])) {
+    private function getParameter($name): ?string {
+      if (isset($_REQUEST[$name]) && is_string($_REQUEST[$name])) {
         return trim($_REQUEST[$name]);
       }
 
       return NULL;
     }
 
-    private function getCurrentStep() {
+    private function getCurrentStep(): int {
 
-      if(!$this->checkRequirements()["success"]) {
+      if (!$this->checkRequirements()["success"]) {
         return self::CHECKING_REQUIREMENTS;
       }
 
@@ -106,12 +106,12 @@ namespace Documents\Install {
       $config = $user->getConfiguration();
 
       // Check if database configuration exists
-      if(!$config->getDatabase()) {
+      if (!$config->getDatabase()) {
         return self::DATABASE_CONFIGURATION;
       }
 
       $sql = $user->getSQL();
-      if(!$sql || !$sql->isConnected()) {
+      if (!$sql || !$sql->isConnected()) {
         return self::DATABASE_CONFIGURATION;
       }
 
@@ -156,33 +156,33 @@ namespace Documents\Install {
       return $step;
     }
 
-    private function checkRequirements() {
+    private function checkRequirements(): array {
 
       $msg = $this->errorString;
       $success = true;
       $failedRequirements = array();
 
       $configDir = "core/Configuration/";
-      if(!is_writeable($configDir)) {
+      if (!is_writeable($configDir)) {
         $failedRequirements[] = "<b>$configDir</b> is not writeable. Try running <b>chmod 700 $configDir</b>";
         $success = false;
       }
 
       if (function_exists("posix_getuid")) {
         $userId = posix_getuid();
-        if(fileowner($configDir) !== $userId) {
+        if (fileowner($configDir) !== $userId) {
           $username = posix_getpwuid($userId)['name'];
           $failedRequirements[] = "<b>$configDir</b> is not owned by current user: $username ($userId). Try running <b>chown -R $username $configDir</b>";
           $success = false;
         }
       }
 
-      if(version_compare(PHP_VERSION, '7.4', '<')) {
-          $failedRequirements[] = "PHP Version <b>>= 7.4</b> is required. Got: <b>" . PHP_VERSION . "</b>";
-          $success = false;
+      if (version_compare(PHP_VERSION, '7.4', '<')) {
+        $failedRequirements[] = "PHP Version <b>>= 7.4</b> is required. Got: <b>" . PHP_VERSION . "</b>";
+        $success = false;
       }
 
-      if(!$success) {
+      if (!$success) {
         $msg = "The following requirements failed the check:<br>" .
           $this->createUnorderedList($failedRequirements);
         $this->errorString = $msg;
@@ -191,7 +191,7 @@ namespace Documents\Install {
       return array("success" => $success, "msg" => $msg);
     }
 
-    private function databaseConfiguration() {
+    private function databaseConfiguration(): array {
 
       $host = $this->getParameter("host");
       $port = $this->getParameter("port");
@@ -204,44 +204,44 @@ namespace Documents\Install {
       $success = true;
 
       $missingInputs = array();
-      if(is_null($host) || empty($host)) {
+      if (is_null($host) || empty($host)) {
         $success = false;
         $missingInputs[] = "Host";
       }
 
-      if(is_null($port) || empty($port)) {
+      if (is_null($port) || empty($port)) {
         $success = false;
         $missingInputs[] = "Port";
       }
 
-      if(is_null($username) || empty($username)) {
+      if (is_null($username) || empty($username)) {
         $success = false;
         $missingInputs[] = "Username";
       }
 
-      if(is_null($password)) {
+      if (is_null($password)) {
         $success = false;
         $missingInputs[] = "Password";
       }
 
-      if(is_null($database) || empty($database)) {
+      if (is_null($database) || empty($database)) {
         $success = false;
         $missingInputs[] = "Database";
       }
 
-      if(is_null($type) || empty($type)) {
+      if (is_null($type) || empty($type)) {
         $success = false;
         $missingInputs[] = "Type";
       }
 
       $supportedTypes = array("mysql", "postgres");
-      if(!$success) {
+      if (!$success) {
         $msg = "Please fill out the following inputs:<br>" .
           $this->createUnorderedList($missingInputs);
-      } else if(!is_numeric($port) || ($port = intval($port)) < 1 || $port > 65535) {
+      } else if (!is_numeric($port) || ($port = intval($port)) < 1 || $port > 65535) {
         $msg = "Port must be in range of 1-65535.";
         $success = false;
-      } else if(!in_array($type, $supportedTypes)) {
+      } else if (!in_array($type, $supportedTypes)) {
         $msg = "Unsupported database type. Must be one of: " . implode(", ", $supportedTypes);
         $success = false;
       } else {
@@ -251,9 +251,9 @@ namespace Documents\Install {
         $connectionData->setProperty('type', $type);
         $sql = SQL::createConnection($connectionData);
         $success = false;
-        if(is_string($sql)) {
+        if (is_string($sql)) {
           $msg = "Error connecting to database: $sql";
-        } else if(!$sql->isConnected()) {
+        } else if (!$sql->isConnected()) {
           if (!$sql->checkRequirements()) {
             $driverName = $sql->getDriverName();
             $installLink = "https://www.php.net/manual/en/$driverName.setup.php";
@@ -267,7 +267,7 @@ namespace Documents\Install {
           $msg = "";
           $success = true;
           $queries = CreateDatabase::createQueries($sql);
-          foreach($queries as $query) {
+          foreach ($queries as $query) {
             if (!($res = $query->execute())) {
               $msg = "Error creating tables: " . $sql->getLastError();
               $success = false;
@@ -276,13 +276,13 @@ namespace Documents\Install {
           }
 
           $config = $this->getDocument()->getUser()->getConfiguration();
-          if(!$config->create("Database", $connectionData)) {
+          if (!$config->create("Database", $connectionData)) {
             $success = false;
             $msg = "Unable to write file";
           }
         }
 
-        if($sql) {
+        if ($sql) {
           $sql->close();
         }
       }
@@ -290,10 +290,10 @@ namespace Documents\Install {
       return array("success" => $success, "msg" => $msg);
     }
 
-    private function createUser() {
+    private function createUser(): array {
 
       $user = $this->getDocument()->getUser();
-      if($this->getParameter("prev") === "true") {
+      if ($this->getParameter("prev") === "true") {
         $success = $user->getConfiguration()->delete("Database");
         $msg = $success ? "" : error_get_last();
         return array("success" => $success, "msg" => $msg);
@@ -307,22 +307,22 @@ namespace Documents\Install {
       $success = true;
       $missingInputs = array();
 
-      if(is_null($username) || empty($username)) {
+      if (is_null($username) || empty($username)) {
         $success = false;
         $missingInputs[] = "Username";
       }
 
-      if(is_null($password) || empty($password)) {
+      if (is_null($password) || empty($password)) {
         $success = false;
         $missingInputs[] = "Password";
       }
 
-      if(is_null($confirmPassword) || empty($confirmPassword)) {
+      if (is_null($confirmPassword) || empty($confirmPassword)) {
         $success = false;
         $missingInputs[] = "Confirm Password";
       }
 
-      if(!$success) {
+      if (!$success) {
         $msg = "Please fill out the following inputs:<br>" .
           $this->createUnorderedList($missingInputs);
       } else {
@@ -347,10 +347,10 @@ namespace Documents\Install {
       return array("msg" => $msg, "success" => $success);
     }
 
-    private function addMailService() {
+    private function addMailService(): array {
 
       $user = $this->getDocument()->getUser();
-      if($this->getParameter("prev") === "true") {
+      if ($this->getParameter("prev") === "true") {
         $sql = $user->getSQL();
         $success = $sql->delete("User")->execute();
         $msg = $sql->getLastError();
@@ -359,9 +359,9 @@ namespace Documents\Install {
 
       $success = true;
       $msg = $this->errorString;
-      if($this->getParameter("skip") === "true") {
+      if ($this->getParameter("skip") === "true") {
         $req = new \Api\Settings\Set($user);
-        $success = $req->execute(array("settings" => array( "mail_enabled" => "0" )));
+        $success = $req->execute(array("settings" => array("mail_enabled" => "0")));
         $msg = $req->getLastError();
       } else {
 
@@ -372,30 +372,30 @@ namespace Documents\Install {
         $success = true;
 
         $missingInputs = array();
-        if(is_null($address) || empty($address)) {
+        if (is_null($address) || empty($address)) {
           $success = false;
           $missingInputs[] = "SMTP Address";
         }
 
-        if(is_null($port) || empty($port)) {
+        if (is_null($port) || empty($port)) {
           $success = false;
           $missingInputs[] = "Port";
         }
 
-        if(is_null($username) || empty($username)) {
+        if (is_null($username) || empty($username)) {
           $success = false;
           $missingInputs[] = "Username";
         }
 
-        if(is_null($password)) {
+        if (is_null($password)) {
           $success = false;
           $missingInputs[] = "Password";
         }
 
-        if(!$success) {
+        if (!$success) {
           $msg = "Please fill out the following inputs:<br>" .
             $this->createUnorderedList($missingInputs);
-        } else if(!is_numeric($port) || ($port = intval($port)) < 1 || $port > 65535) {
+        } else if (!is_numeric($port) || ($port = intval($port)) < 1 || $port > 65535) {
           $msg = "Port must be in range of 1-65535.";
           $success = false;
         } else {
@@ -413,7 +413,7 @@ namespace Documents\Install {
 
           try {
             $success = $mail->SmtpConnect();
-            if(!$success) {
+            if (!$success) {
               $error = empty($mail->ErrorInfo) ? "Unknown Error" : $mail->ErrorInfo;
               $msg = "Could not connect to SMTP Server: $error";
             } else {
@@ -421,11 +421,11 @@ namespace Documents\Install {
               $msg = "";
               $mail->smtpClose();
             }
-          } catch(Exception $error) {
+          } catch (Exception $error) {
             $msg = "Could not connect to SMTP Server: " . $error->errorMessage();
           }
 
-          if($success) {
+          if ($success) {
             $req = new \Api\Settings\Set($user);
             $success = $req->execute(array("settings" => array(
               "mail_enabled" => "1",
@@ -442,9 +442,9 @@ namespace Documents\Install {
       return array("success" => $success, "msg" => $msg);
     }
 
-    private function performStep() {
+    private function performStep(): array {
 
-      switch($this->currentStep) {
+      switch ($this->currentStep) {
 
         case self::CHECKING_REQUIREMENTS:
           return $this->checkRequirements();
@@ -466,30 +466,30 @@ namespace Documents\Install {
       }
     }
 
-    private function createProgressSidebar() {
+    private function createProgressSidebar(): string {
       $items = array();
-      foreach($this->steps as $num => $step) {
+      foreach ($this->steps as $num => $step) {
 
         $title = $step["title"];
         $status = $step["status"];
         $currentStep = ($num == $this->currentStep) ? " id=\"currentStep\"" : "";
 
-        switch($status) {
+        switch ($status) {
           case self::PENDING:
-            $statusIcon  = $this->createIcon("spinner");
-            $statusText  = "Loading…";
+            $statusIcon = $this->createIcon("spinner");
+            $statusText = "Loading…";
             $statusColor = "muted";
             break;
 
           case self::SUCCESSFUL:
-            $statusIcon  = $this->createIcon("check-circle");
-            $statusText  = "Successful";
+            $statusIcon = $this->createIcon("check-circle");
+            $statusText = "Successful";
             $statusColor = "success";
             break;
 
           case self::ERROR:
-            $statusIcon  = $this->createIcon("times-circle");
-            $statusText  = "Failed";
+            $statusIcon = $this->createIcon("times-circle");
+            $statusText = "Failed";
             $statusColor = "danger";
             break;
 
@@ -514,11 +514,11 @@ namespace Documents\Install {
       return implode("", $items);
     }
 
-    private function createFormItem($formItem, $inline=false) {
+    private function createFormItem($formItem, $inline = false): string {
 
       $title = $formItem["title"];
-      $name  = $formItem["name"];
-      $type  = $formItem["type"];
+      $name = $formItem["name"];
+      $type = $formItem["type"];
 
       $attributes = array(
         "name" => $name,
@@ -526,37 +526,37 @@ namespace Documents\Install {
         "class" => "form-control"
       );
 
-      if(isset($formItem["required"]) && $formItem["required"]) {
+      if (isset($formItem["required"]) && $formItem["required"]) {
         $attributes["required"] = "";
       }
 
       if ($type !== "select") {
         $attributes["type"] = $type;
 
-        if(isset($formItem["value"]) && $formItem["value"]) {
+        if (isset($formItem["value"]) && $formItem["value"]) {
           $attributes["value"] = $formItem["value"];
         }
 
-        if($type === "number") {
-          if(isset($formItem["min"]) && is_numeric($formItem["min"]))
+        if ($type === "number") {
+          if (isset($formItem["min"]) && is_numeric($formItem["min"]))
             $attributes["min"] = $formItem["min"];
-          if(isset($formItem["max"]) && is_numeric($formItem["max"]))
+          if (isset($formItem["max"]) && is_numeric($formItem["max"]))
             $attributes["max"] = $formItem["max"];
-          if(isset($formItem["step"]) && is_numeric($formItem["step"]))
+          if (isset($formItem["step"]) && is_numeric($formItem["step"]))
             $attributes["step"] = $formItem["step"];
         }
       }
 
       $replacements = array("+" => " ", "&" => "\" ", "=" => "=\"");
       $attributes = http_build_query($attributes) . "\"";
-      foreach($replacements as $key => $val) {
+      foreach ($replacements as $key => $val) {
         $attributes = str_replace($key, $val, $attributes);
       }
 
       if ($type === "select") {
         $items = $formItem["items"] ?? array();
         $element = "<select $attributes>";
-        foreach($items as $key => $val) {
+        foreach ($items as $key => $val) {
           $element .= "<option value=\"$key\">$val</option>";
         }
         $element .= "</select>";
@@ -564,7 +564,7 @@ namespace Documents\Install {
         $element = "<input $attributes>";
       }
 
-      if(!$inline) {
+      if (!$inline) {
         return
           "<div class=\"d-block my-3\">
             <label for=\"$name\">$title</label>
@@ -579,7 +579,7 @@ namespace Documents\Install {
       }
     }
 
-    private function createProgessMainview() {
+    private function createProgessMainview(): string {
 
       $views = array(
         self::CHECKING_REQUIREMENTS => array(
@@ -592,21 +592,21 @@ namespace Documents\Install {
             array("title" => "Database Type", "name" => "type", "type" => "select", "required" => true, "items" => array(
               "mysql" => "MySQL", "postgres" => "PostgreSQL"
             )),
-            array("title" => "Username", "name"  => "username", "type"  => "text", "required" => true),
-            array("title" => "Password", "name"  => "password", "type"  => "password"),
-            array("title" => "Database", "name"  => "database", "type"  => "text", "required" => true),
+            array("title" => "Username", "name" => "username", "type" => "text", "required" => true),
+            array("title" => "Password", "name" => "password", "type" => "password"),
+            array("title" => "Database", "name" => "database", "type" => "text", "required" => true),
             array("type" => "row", "items" => array(
               array(
-                "title" => "Address", "name"  => "host", "type"  => "text", "required" => true,
+                "title" => "Address", "name" => "host", "type" => "text", "required" => true,
                 "value" => "localhost", "row" => true
               ),
               array(
-                "title" => "Port", "name"  => "port", "type"  => "number", "required" => true,
+                "title" => "Port", "name" => "port", "type" => "number", "required" => true,
                 "value" => "3306", "min" => "1", "max" => "65535", "row" => true
               )
             )),
             array(
-              "title" => "Encoding", "name"  => "encoding", "type"  => "text", "required" => false,
+              "title" => "Encoding", "name" => "encoding", "type" => "text", "required" => false,
               "value" => "UTF-8"
             ),
           )
@@ -614,25 +614,25 @@ namespace Documents\Install {
         self::CREATE_USER => array(
           "title" => "Create a User",
           "form" => array(
-            array("title" => "Username", "name"  => "username", "type"  => "text", "required" => true),
-            array("title" => "Email", "name"  => "email", "type"  => "text"),
-            array("title" => "Password", "name"  => "password", "type"  => "password", "required" => true),
-            array("title" => "Confirm Password", "name"  => "confirmPassword", "type"  => "password", "required" => true),
+            array("title" => "Username", "name" => "username", "type" => "text", "required" => true),
+            array("title" => "Email", "name" => "email", "type" => "text"),
+            array("title" => "Password", "name" => "password", "type" => "password", "required" => true),
+            array("title" => "Confirm Password", "name" => "confirmPassword", "type" => "password", "required" => true),
           ),
           "previousButton" => true
         ),
         self::ADD_MAIL_SERVICE => array(
           "title" => "Optional: Add Mail Service",
           "form" => array(
-            array("title" => "Username", "name"  => "username", "type"  => "text", "required" => true),
-            array("title" => "Password", "name"  => "password", "type"  => "password"),
+            array("title" => "Username", "name" => "username", "type" => "text", "required" => true),
+            array("title" => "Password", "name" => "password", "type" => "password"),
             array("type" => "row", "items" => array(
               array(
-                "title" => "SMTP Address", "name"  => "address", "type"  => "text", "required" => true,
+                "title" => "SMTP Address", "name" => "address", "type" => "text", "required" => true,
                 "value" => "localhost", "row" => true
               ),
               array(
-                "title" => "Port", "name"  => "port", "type"  => "number", "required" => true,
+                "title" => "Port", "name" => "port", "type" => "number", "required" => true,
                 "value" => "587", "min" => "1", "max" => "65535", "row" => true
               )
             )),
@@ -646,7 +646,7 @@ namespace Documents\Install {
         )
       );
 
-      if(!isset($views[$this->currentStep])) {
+      if (!isset($views[$this->currentStep])) {
         return "";
       }
 
@@ -657,24 +657,24 @@ namespace Documents\Install {
 
       $html = "<h4 class=\"mb-3\">$title</h4><hr class=\"mb-4\">";
 
-      if(isset($currentView["text"])) {
+      if (isset($currentView["text"])) {
         $text = $currentView["text"];
         $html .= "<div class=\"my-3\">$text</i></div>";
       }
 
-      if(isset($currentView["progressText"])) {
+      if (isset($currentView["progressText"])) {
         $progressText = $currentView["progressText"];
         $html .= "<div id=\"progressText\" style=\"display:none\" class=\"my-3\">$progressText$spinnerIcon</i></div>";
       }
 
-      if(isset($currentView["form"])) {
+      if (isset($currentView["form"])) {
         $html .= "<form id=\"installForm\">";
 
-        foreach($currentView["form"] as $formItem) {
+        foreach ($currentView["form"] as $formItem) {
 
-          if($formItem["type"] === "row") {
+          if ($formItem["type"] === "row") {
             $html .= "<div class=\"row\">";
-            foreach($formItem["items"] as $item) {
+            foreach ($formItem["items"] as $item) {
               $html .= $this->createFormItem($item, true);
             }
             $html .= "</div>";
@@ -691,7 +691,7 @@ namespace Documents\Install {
         array("title" => "Go Back", "type" => "info", "id" => "btnPrev", "float" => "left", "disabled" => $prevDisabled)
       );
 
-      if($this->currentStep != self::FINISH_INSTALLATION) {
+      if ($this->currentStep != self::FINISH_INSTALLATION) {
         if ($this->currentStep == self::CHECKING_REQUIREMENTS) {
           $buttons[] = array("title" => "Retry", "type" => "success", "id" => "btnRetry", "float" => "right");
         } else {
@@ -701,14 +701,14 @@ namespace Documents\Install {
         $buttons[] = array("title" => "Finish", "type" => "success", "id" => "btnFinish", "float" => "right");
       }
 
-      if(isset($currentView["skip"])) {
+      if (isset($currentView["skip"])) {
         $buttons[] = array("title" => "Skip", "type" => "secondary", "id" => "btnSkip", "float" => "right");
       }
 
       $buttonsLeft = "";
       $buttonsRight = "";
 
-      foreach($buttons as $button) {
+      foreach ($buttons as $button) {
         $title = $button["title"];
         $type = $button["type"];
         $id = $button["id"];
@@ -716,7 +716,7 @@ namespace Documents\Install {
         $disabled = (isset($button["disabled"]) && $button["disabled"]) ? " disabled" : "";
         $button = "<button type=\"button\" id=\"$id\" class=\"btn btn-$type m-1\"$disabled>$title</button>";
 
-        if($float === "left") {
+        if ($float === "left") {
           $buttonsLeft .= $button;
         } else {
           $buttonsRight .= $button;
@@ -732,7 +732,7 @@ namespace Documents\Install {
       return $html;
     }
 
-    function getCode() {
+    function getCode(): string {
       $html = parent::getCode();
 
       $this->steps = array(
@@ -761,16 +761,16 @@ namespace Documents\Install {
       $this->currentStep = $this->getCurrentStep();
 
       // set status
-      for($step = self::CHECKING_REQUIREMENTS; $step < $this->currentStep; $step++) {
+      for ($step = self::CHECKING_REQUIREMENTS; $step < $this->currentStep; $step++) {
         $this->steps[$step]["status"] = self::SUCCESSFUL;
       }
 
-      if($this->currentStep == self::FINISH_INSTALLATION) {
+      if ($this->currentStep == self::FINISH_INSTALLATION) {
         $this->steps[$this->currentStep]["status"] = self::SUCCESSFUL;
       }
 
       // POST
-      if($_SERVER['REQUEST_METHOD'] == 'POST') {
+      if ($_SERVER['REQUEST_METHOD'] == 'POST') {
         $response = $this->performStep();
         $response["step"] = $this->currentStep;
         die(json_encode($response));
diff --git a/core/Driver/SQL/Column/BoolColumn.class.php b/core/Driver/SQL/Column/BoolColumn.class.php
index 759abdb..f4607bc 100644
--- a/core/Driver/SQL/Column/BoolColumn.class.php
+++ b/core/Driver/SQL/Column/BoolColumn.class.php
@@ -4,7 +4,7 @@ namespace Driver\SQL\Column;
 
 class BoolColumn extends Column {
 
-  public function __construct($name, $defaultValue=false) {
+  public function __construct(string $name, bool $defaultValue = false) {
     parent::__construct($name, false, $defaultValue);
   }
 
diff --git a/core/Driver/SQL/Column/Column.class.php b/core/Driver/SQL/Column/Column.class.php
index 1693928..dd7e207 100644
--- a/core/Driver/SQL/Column/Column.class.php
+++ b/core/Driver/SQL/Column/Column.class.php
@@ -8,14 +8,14 @@ class Column {
   private bool $nullable;
   private $defaultValue;
 
-  public function __construct($name, $nullable = false, $defaultValue = NULL) {
+  public function __construct(string $name, bool $nullable = false, $defaultValue = NULL) {
     $this->name = $name;
     $this->nullable = $nullable;
     $this->defaultValue = $defaultValue;
   }
 
-  public function getName() { return $this->name; }
-  public function notNull() { return !$this->nullable; }
+  public function getName(): string { return $this->name; }
+  public function notNull(): bool { return !$this->nullable; }
   public function getDefaultValue() { return $this->defaultValue; }
 
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Column/DateTimeColumn.class.php b/core/Driver/SQL/Column/DateTimeColumn.class.php
index c7310c9..c082b3d 100644
--- a/core/Driver/SQL/Column/DateTimeColumn.class.php
+++ b/core/Driver/SQL/Column/DateTimeColumn.class.php
@@ -4,7 +4,7 @@ namespace Driver\SQL\Column;
 
 class DateTimeColumn extends Column {
 
-  public function __construct($name, $nullable=false, $defaultValue=NULL) {
+  public function __construct(string $name, bool $nullable = false, $defaultValue = NULL) {
     parent::__construct($name, $nullable, $defaultValue);
   }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Column/EnumColumn.class.php b/core/Driver/SQL/Column/EnumColumn.class.php
index 833d536..f76c3cc 100644
--- a/core/Driver/SQL/Column/EnumColumn.class.php
+++ b/core/Driver/SQL/Column/EnumColumn.class.php
@@ -6,10 +6,10 @@ class EnumColumn extends Column {
 
   private array $values;
 
-  public function __construct($name, $values, $nullable=false, $defaultValue=NULL) {
+  public function __construct(string $name, array $values, bool $nullable = false, $defaultValue = NULL) {
     parent::__construct($name, $nullable, $defaultValue);
     $this->values = $values;
   }
 
-  public function getValues() { return $this->values; }
+  public function getValues(): array { return $this->values; }
 }
diff --git a/core/Driver/SQL/Column/IntColumn.class.php b/core/Driver/SQL/Column/IntColumn.class.php
index 2cea131..d6954e6 100644
--- a/core/Driver/SQL/Column/IntColumn.class.php
+++ b/core/Driver/SQL/Column/IntColumn.class.php
@@ -4,7 +4,7 @@ namespace Driver\SQL\Column;
 
 class IntColumn extends Column {
 
-  public function __construct($name, $nullable=false, $defaultValue=NULL) {
+  public function __construct(string $name, bool $nullable = false, $defaultValue = NULL) {
     parent::__construct($name, $nullable, $defaultValue);
   }
 
diff --git a/core/Driver/SQL/Column/JsonColumn.class.php b/core/Driver/SQL/Column/JsonColumn.class.php
index bc7ad92..c89fa93 100644
--- a/core/Driver/SQL/Column/JsonColumn.class.php
+++ b/core/Driver/SQL/Column/JsonColumn.class.php
@@ -4,7 +4,7 @@ namespace Driver\SQL\Column;
 
 class JsonColumn extends Column {
 
-  public function __construct($name, $nullable=false, $defaultValue=null) {
+  public function __construct(string $name, bool $nullable = false, $defaultValue = null) {
     parent::__construct($name, $nullable, $defaultValue);
   }
 
diff --git a/core/Driver/SQL/Column/SerialColumn.class.php b/core/Driver/SQL/Column/SerialColumn.class.php
index 5e1a6d3..14ffe2f 100644
--- a/core/Driver/SQL/Column/SerialColumn.class.php
+++ b/core/Driver/SQL/Column/SerialColumn.class.php
@@ -4,7 +4,7 @@ namespace Driver\SQL\Column;
 
 class SerialColumn extends Column {
 
-  public function __construct($name, $defaultValue=NULL) {
+  public function __construct(string $name, $defaultValue = NULL) {
     parent::__construct($name, false, $defaultValue); # not nullable
   }
 
diff --git a/core/Driver/SQL/Column/StringColumn.class.php b/core/Driver/SQL/Column/StringColumn.class.php
index 7ac78f7..3e266ea 100644
--- a/core/Driver/SQL/Column/StringColumn.class.php
+++ b/core/Driver/SQL/Column/StringColumn.class.php
@@ -6,10 +6,10 @@ class StringColumn extends Column {
 
   private ?int $maxSize;
 
-  public function __construct($name, $maxSize=null, $nullable=false, $defaultValue=null) {
+  public function __construct(string $name, ?int $maxSize = null, bool $nullable = false, $defaultValue = null) {
     parent::__construct($name, $nullable, $defaultValue);
     $this->maxSize = $maxSize;
   }
 
-  public function getMaxSize() { return $this->maxSize; }
+  public function getMaxSize(): ?int { return $this->maxSize; }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Condition/Compare.class.php b/core/Driver/SQL/Condition/Compare.class.php
index 6ed475b..c9df65b 100644
--- a/core/Driver/SQL/Condition/Compare.class.php
+++ b/core/Driver/SQL/Condition/Compare.class.php
@@ -8,14 +8,14 @@ class Compare extends Condition {
   private string $column;
   private $value;
 
-  public function __construct($col, $val, $operator='=') {
+  public function __construct(string $col, $val, string $operator = '=') {
     $this->operator = $operator;
     $this->column = $col;
     $this->value = $val;
   }
 
-  public function getColumn() { return $this->column; }
+  public function getColumn(): string { return $this->column; }
   public function getValue() { return $this->value; }
-  public function getOperator() { return $this->operator; }
+  public function getOperator(): string { return $this->operator; }
 
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Condition/CondAnd.class.php b/core/Driver/SQL/Condition/CondAnd.class.php
index 4c5f2c7..86a9b59 100644
--- a/core/Driver/SQL/Condition/CondAnd.class.php
+++ b/core/Driver/SQL/Condition/CondAnd.class.php
@@ -10,5 +10,5 @@ class CondAnd extends Condition {
     $this->conditions = $conditions;
   }
 
-  public function getConditions() { return $this->conditions; }
+  public function getConditions(): array { return $this->conditions; }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Condition/CondIn.class.php b/core/Driver/SQL/Condition/CondIn.class.php
index 0968413..a77bcf6 100644
--- a/core/Driver/SQL/Condition/CondIn.class.php
+++ b/core/Driver/SQL/Condition/CondIn.class.php
@@ -12,6 +12,6 @@ class CondIn extends Condition {
     $this->expression = $expression;
   }
 
-  public function getColumn() { return $this->column; }
+  public function getColumn(): string { return $this->column; }
   public function getExpression() { return $this->expression; }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Condition/CondKeyword.class.php b/core/Driver/SQL/Condition/CondKeyword.class.php
index a153da6..9bf0e76 100644
--- a/core/Driver/SQL/Condition/CondKeyword.class.php
+++ b/core/Driver/SQL/Condition/CondKeyword.class.php
@@ -8,7 +8,7 @@ abstract class CondKeyword extends Condition {
   private $rightExpression;
   private string $keyword;
 
-  public function __construct($keyword, $leftExpression, $rightExpression) {
+  public function __construct(string $keyword, $leftExpression, $rightExpression) {
     $this->leftExpression = $leftExpression;
     $this->rightExpression = $rightExpression;
     $this->keyword = $keyword;
@@ -16,5 +16,5 @@ abstract class CondKeyword extends Condition {
 
   public function getLeftExp() { return $this->leftExpression; }
   public function getRightExp() { return $this->rightExpression; }
-  public function getKeyword() { return $this->keyword; }
+  public function getKeyword(): string { return $this->keyword; }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Condition/CondNull.class.php b/core/Driver/SQL/Condition/CondNull.class.php
index 260ad67..888ab71 100644
--- a/core/Driver/SQL/Condition/CondNull.class.php
+++ b/core/Driver/SQL/Condition/CondNull.class.php
@@ -10,5 +10,5 @@ class CondNull extends Condition {
     $this->column = $col;
   }
 
-  public function getColumn() { return $this->column; }
+  public function getColumn(): string { return $this->column; }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Condition/CondOr.class.php b/core/Driver/SQL/Condition/CondOr.class.php
index b92ab6b..d80614d 100644
--- a/core/Driver/SQL/Condition/CondOr.class.php
+++ b/core/Driver/SQL/Condition/CondOr.class.php
@@ -10,5 +10,5 @@ class CondOr extends Condition {
     $this->conditions = (!empty($conditions) && is_array($conditions[0])) ? $conditions[0] : $conditions;
   }
 
-  public function getConditions() { return $this->conditions; }
+  public function getConditions(): array { return $this->conditions; }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Constraint/Constraint.class.php b/core/Driver/SQL/Constraint/Constraint.class.php
index 09e90fd..27aeb86 100644
--- a/core/Driver/SQL/Constraint/Constraint.class.php
+++ b/core/Driver/SQL/Constraint/Constraint.class.php
@@ -10,5 +10,5 @@ abstract class Constraint {
     $this->columnNames = (!is_array($columnNames) ? array($columnNames) : $columnNames);
   }
 
-  public function getColumnNames() { return $this->columnNames; }
+  public function getColumnNames(): array { return $this->columnNames; }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Constraint/ForeignKey.class.php b/core/Driver/SQL/Constraint/ForeignKey.class.php
index 5f46366..221001d 100644
--- a/core/Driver/SQL/Constraint/ForeignKey.class.php
+++ b/core/Driver/SQL/Constraint/ForeignKey.class.php
@@ -10,14 +10,14 @@ class ForeignKey extends Constraint {
   private string $referencedColumn;
   private ?Strategy $strategy;
 
-  public function __construct($name, $refTable, $refColumn, $strategy = NULL) {
+  public function __construct(string $name, string $refTable, string $refColumn, ?Strategy $strategy = NULL) {
     parent::__construct($name);
     $this->referencedTable = $refTable;
     $this->referencedColumn = $refColumn;
     $this->strategy = $strategy;
   }
 
-  public function getReferencedTable() { return $this->referencedTable; }
-  public function getReferencedColumn() { return $this->referencedColumn; }
-  public function onDelete() { return $this->strategy; }
+  public function getReferencedTable(): string { return $this->referencedTable; }
+  public function getReferencedColumn(): string { return $this->referencedColumn; }
+  public function onDelete(): ?Strategy { return $this->strategy; }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Expression/Add.class.php b/core/Driver/SQL/Expression/Add.class.php
index 61faffb..1d4df42 100644
--- a/core/Driver/SQL/Expression/Add.class.php
+++ b/core/Driver/SQL/Expression/Add.class.php
@@ -4,9 +4,10 @@ namespace Driver\SQL\Expression;
 
 use Driver\SQL\Condition\Compare;
 
+# TODO: change confusing class inheritance here
 class Add extends Compare {
 
-  public function __construct($col, $val) {
+  public function __construct(string $col, $val) {
     parent::__construct($col, $val, "+");
   }
 
diff --git a/core/Driver/SQL/Join.class.php b/core/Driver/SQL/Join.class.php
index b45b550..cedf17d 100644
--- a/core/Driver/SQL/Join.class.php
+++ b/core/Driver/SQL/Join.class.php
@@ -8,9 +8,9 @@ class Join {
   private string $table;
   private string $columnA;
   private string $columnB;
-  private $tableAlias;
+  private ?string $tableAlias;
 
-  public function __construct($type, $table, $columnA, $columnB, $tableAlias=null) {
+  public function __construct(string $type, string $table, string $columnA, string $columnB, ?string $tableAlias = null) {
     $this->type = $type;
     $this->table = $table;
     $this->columnA = $columnA;
@@ -18,10 +18,10 @@ class Join {
     $this->tableAlias = $tableAlias;
   }
 
-  public function getType() { return $this->type; }
-  public function getTable() { return $this->table; }
-  public function getColumnA() { return $this->columnA; }
-  public function getColumnB() { return $this->columnB; }
-  public function getTableAlias() { return $this->tableAlias; }
+  public function getType(): string { return $this->type; }
+  public function getTable(): string { return $this->table; }
+  public function getColumnA(): string { return $this->columnA; }
+  public function getColumnB(): string { return $this->columnB; }
+  public function getTableAlias(): ?string { return $this->tableAlias; }
 
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Keyword.class.php b/core/Driver/SQL/Keyword.class.php
index d613885..69315d5 100644
--- a/core/Driver/SQL/Keyword.class.php
+++ b/core/Driver/SQL/Keyword.class.php
@@ -6,10 +6,10 @@ class Keyword {
 
   private string $value;
 
-  public function __construct($value) {
+  public function __construct(string $value) {
     $this->value = $value;
   }
 
-  public function getValue() { return $this->value; }
+  public function getValue(): string { return $this->value; }
 
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Query/CreateTable.class.php b/core/Driver/SQL/Query/CreateTable.class.php
index 5743747..27c2a47 100644
--- a/core/Driver/SQL/Query/CreateTable.class.php
+++ b/core/Driver/SQL/Query/CreateTable.class.php
@@ -13,6 +13,8 @@ use Driver\SQL\Column\JsonColumn;
 use Driver\SQL\Constraint\PrimaryKey;
 use Driver\SQL\Constraint\Unique;
 use Driver\SQL\Constraint\ForeignKey;
+use Driver\SQL\SQL;
+use Driver\SQL\Strategy\Strategy;
 
 class CreateTable extends Query {
 
@@ -21,7 +23,7 @@ class CreateTable extends Query {
   private array $constraints;
   private bool $ifNotExists;
 
-  public function __construct($sql, $name) {
+  public function __construct(SQL $sql, string $name) {
     parent::__construct($sql);
     $this->tableName = $name;
     $this->columns = array();
@@ -29,67 +31,67 @@ class CreateTable extends Query {
     $this->ifNotExists = false;
   }
 
-  public function addSerial($name) {
+  public function addSerial(string $name): CreateTable {
     $this->columns[$name] = new SerialColumn($name);
     return $this;
   }
 
-  public function addString($name, $maxSize=NULL, $nullable=false, $defaultValue=NULL) {
+  public function addString(string $name, ?int $maxSize = NULL, bool $nullable = false, $defaultValue = NULL): CreateTable {
     $this->columns[$name] = new StringColumn($name, $maxSize, $nullable, $defaultValue);
     return $this;
   }
 
-  public function addDateTime($name, $nullable=false, $defaultValue=NULL) {
+  public function addDateTime(string $name, bool $nullable = false, $defaultValue = NULL): CreateTable {
     $this->columns[$name] = new DateTimeColumn($name, $nullable, $defaultValue);
     return $this;
   }
 
-  public function addInt($name, $nullable=false, $defaultValue=NULL) {
+  public function addInt(string $name, bool $nullable = false, $defaultValue = NULL): CreateTable {
     $this->columns[$name] = new IntColumn($name, $nullable, $defaultValue);
     return $this;
   }
 
-  public function addBool($name, $defaultValue=false) {
+  public function addBool(string $name, $defaultValue = false): CreateTable {
     $this->columns[$name] = new BoolColumn($name, $defaultValue);
     return $this;
   }
 
-  public function addJson($name, $nullable=false, $defaultValue=NULL) {
+  public function addJson(string $name, bool $nullable = false, $defaultValue = NULL): CreateTable {
     $this->columns[$name] = new JsonColumn($name, $nullable, $defaultValue);
     return $this;
   }
 
-  public function addEnum($name, $values, $nullable=false, $defaultValue=NULL) {
+  public function addEnum(string $name, array $values, bool $nullable = false, $defaultValue = NULL): CreateTable {
     $this->columns[$name] = new EnumColumn($name, $values, $nullable, $defaultValue);
     return $this;
   }
 
-  public function primaryKey(...$names) {
+  public function primaryKey(...$names): CreateTable {
     $this->constraints[] = new PrimaryKey($names);
     return $this;
   }
 
-  public function unique(...$names) {
+  public function unique(...$names): CreateTable {
     $this->constraints[] = new Unique($names);
     return $this;
   }
 
-  public function foreignKey($name, $refTable, $refColumn, $strategy = NULL) {
+  public function foreignKey(string $name, string $refTable, string $refColumn, ?Strategy $strategy = NULL): CreateTable {
     $this->constraints[] = new ForeignKey($name, $refTable, $refColumn, $strategy);
     return $this;
   }
 
-  public function onlyIfNotExists() {
+  public function onlyIfNotExists(): CreateTable {
     $this->ifNotExists = true;
     return $this;
   }
 
-  public function execute() {
+  public function execute(): bool {
     return $this->sql->executeCreateTable($this);
   }
 
-  public function ifNotExists() { return $this->ifNotExists; }
-  public function getTableName() { return $this->tableName; }
-  public function getColumns() { return $this->columns; }
-  public function getConstraints() { return $this->constraints; }
+  public function ifNotExists(): bool { return $this->ifNotExists; }
+  public function getTableName(): string { return $this->tableName; }
+  public function getColumns(): array { return $this->columns; }
+  public function getConstraints(): array { return $this->constraints; }
 }
diff --git a/core/Driver/SQL/Query/Delete.class.php b/core/Driver/SQL/Query/Delete.class.php
index 705fbfe..4f993e9 100644
--- a/core/Driver/SQL/Query/Delete.class.php
+++ b/core/Driver/SQL/Query/Delete.class.php
@@ -3,19 +3,20 @@
 namespace Driver\SQL\Query;
 
 use Driver\SQL\Condition\CondOr;
+use Driver\SQL\SQL;
 
 class Delete extends Query {
 
   private string $table;
   private array $conditions;
 
-  public function __construct($sql, $table) {
+  public function __construct(SQL $sql, string $table) {
     parent::__construct($sql);
     $this->table = $table;
     $this->conditions = array();
   }
 
-  public function where(...$conditions) {
+  public function where(...$conditions): Delete {
     $this->conditions[] = (count($conditions) === 1 ? $conditions : new CondOr($conditions));
     return $this;
   }
@@ -24,6 +25,6 @@ class Delete extends Query {
     return $this->sql->executeDelete($this);
   }
 
-  public function getTable() { return $this->table; }
-  public function getConditions() { return $this->conditions; }
+  public function getTable(): string { return $this->table; }
+  public function getConditions(): array { return $this->conditions; }
 }
diff --git a/core/Driver/SQL/Query/Drop.php b/core/Driver/SQL/Query/Drop.php
index 9938a57..ebcc193 100644
--- a/core/Driver/SQL/Query/Drop.php
+++ b/core/Driver/SQL/Query/Drop.php
@@ -14,16 +14,16 @@ class Drop extends Query {
    * @param SQL $sql
    * @param string $table
    */
-  public function __construct(\Driver\SQL\SQL $sql, string $table) {
+  public function __construct(SQL $sql, string $table) {
     parent::__construct($sql);
     $this->table = $table;
   }
 
-  public function execute() {
-    $this->sql->executeDrop($this);
+  public function execute(): bool {
+    return $this->sql->executeDrop($this);
   }
 
-  public function getTable() {
+  public function getTable(): string {
     return $this->table;
   }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Query/Insert.class.php b/core/Driver/SQL/Query/Insert.class.php
index 308aa87..aa0e2ea 100644
--- a/core/Driver/SQL/Query/Insert.class.php
+++ b/core/Driver/SQL/Query/Insert.class.php
@@ -2,6 +2,7 @@
 
 namespace Driver\SQL\Query;
 
+use Driver\SQL\SQL;
 use Driver\SQL\Strategy\Strategy;
 
 class Insert extends Query {
@@ -12,7 +13,7 @@ class Insert extends Query {
   private ?Strategy $onDuplicateKey;
   private ?string $returning;
 
-  public function __construct($sql, $name, $columns=array()) {
+  public function __construct(SQL $sql, string $name, array $columns = array()) {
     parent::__construct($sql);
     $this->tableName = $name;
     $this->columns = $columns;
@@ -21,28 +22,28 @@ class Insert extends Query {
     $this->returning = NULL;
   }
 
-  public function addRow(...$values) {
+  public function addRow(...$values): Insert {
     $this->rows[] = $values;
     return $this;
   }
 
-  public function onDuplicateKeyStrategy($strategy) {
+  public function onDuplicateKeyStrategy(Strategy $strategy): Insert {
     $this->onDuplicateKey = $strategy;
     return $this;
   }
 
-  public function returning($column) {
+  public function returning(string $column): Insert {
     $this->returning = $column;
     return $this;
   }
 
-  public function execute() {
+  public function execute(): bool {
     return $this->sql->executeInsert($this);
   }
 
-  public function getTableName() { return $this->tableName; }
-  public function getColumns() { return $this->columns; }
-  public function getRows() { return $this->rows; }
-  public function onDuplicateKey() { return $this->onDuplicateKey; }
-  public function getReturning() { return $this->returning; }
+  public function getTableName(): string { return $this->tableName; }
+  public function getColumns(): array { return $this->columns; }
+  public function getRows(): array { return $this->rows; }
+  public function onDuplicateKey(): ?Strategy { return $this->onDuplicateKey; }
+  public function getReturning(): ?string { return $this->returning; }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Query/Query.class.php b/core/Driver/SQL/Query/Query.class.php
index b58a3b7..f6201de 100644
--- a/core/Driver/SQL/Query/Query.class.php
+++ b/core/Driver/SQL/Query/Query.class.php
@@ -9,16 +9,16 @@ abstract class Query {
   protected SQL $sql;
   public bool $dump;
 
-  public function __construct($sql) {
+  public function __construct(SQL $sql) {
     $this->sql = $sql;
     $this->dump = false;
   }
 
-  public function dump() {
+  public function dump(): Query {
     $this->dump = true;
     return $this;
   }
 
-  public abstract function execute();
+  public abstract function execute(): bool;
 
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Query/Select.class.php b/core/Driver/SQL/Query/Select.class.php
index aec1641..29f141f 100644
--- a/core/Driver/SQL/Query/Select.class.php
+++ b/core/Driver/SQL/Query/Select.class.php
@@ -30,68 +30,68 @@ class Select extends Query {
     $this->sortAscending = true;
   }
 
-  public function from(...$tables) {
+  public function from(...$tables): Select {
     $this->tables = array_merge($this->tables, $tables);
     return $this;
   }
 
-  public function where(...$conditions) {
+  public function where(...$conditions): Select {
     $this->conditions[] = (count($conditions) === 1 ? $conditions : new CondOr($conditions));
     return $this;
   }
 
-  public function innerJoin($table, $columnA, $columnB, $tableAlias=null) {
+  public function innerJoin(string $table, string $columnA, string $columnB, ?string $tableAlias = null): Select {
     $this->joins[] = new Join("INNER", $table, $columnA, $columnB, $tableAlias);
     return $this;
   }
 
-  public function leftJoin($table, $columnA, $columnB, $tableAlias=null) {
+  public function leftJoin(string $table, string $columnA, string $columnB, ?string $tableAlias = null): Select {
     $this->joins[] = new Join("LEFT", $table, $columnA, $columnB, $tableAlias);
     return $this;
   }
 
-  public function groupBy(...$columns) {
+  public function groupBy(...$columns): Select {
     $this->groupColumns = $columns;
     return $this;
   }
 
-  public function orderBy(...$columns) {
+  public function orderBy(...$columns): Select {
     $this->orderColumns = $columns;
     return $this;
   }
 
-  public function ascending() {
+  public function ascending(): Select {
     $this->sortAscending = true;
     return $this;
   }
 
-  public function descending() {
+  public function descending(): Select {
     $this->sortAscending = false;
     return $this;
   }
 
-  public function limit($limit) {
+  public function limit(int $limit): Select {
     $this->limit = $limit;
     return $this;
   }
 
-  public function offset($offset) {
+  public function offset(int $offset): Select {
     $this->offset = $offset;
     return $this;
   }
 
-  public function execute() {
+  public function execute(): bool {
     return $this->sql->executeSelect($this);
   }
 
-  public function getColumns() { return $this->columns; }
-  public function getTables() { return $this->tables; }
-  public function getConditions() { return $this->conditions; }
-  public function getJoins() { return $this->joins; }
-  public function isOrderedAscending() { return $this->sortAscending; }
-  public function getOrderBy() { return $this->orderColumns; }
-  public function getLimit() { return $this->limit; }
-  public function getOffset() { return $this->offset; }
-  public function getGroupBy() { return $this->groupColumns; }
+  public function getColumns(): array { return $this->columns; }
+  public function getTables(): array { return $this->tables; }
+  public function getConditions(): array { return $this->conditions; }
+  public function getJoins(): array { return $this->joins; }
+  public function isOrderedAscending(): bool { return $this->sortAscending; }
+  public function getOrderBy(): array { return $this->orderColumns; }
+  public function getLimit(): int { return $this->limit; }
+  public function getOffset(): int { return $this->offset; }
+  public function getGroupBy(): array { return $this->groupColumns; }
 
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Query/Truncate.class.php b/core/Driver/SQL/Query/Truncate.class.php
index d2c0478..7cb57c4 100644
--- a/core/Driver/SQL/Query/Truncate.class.php
+++ b/core/Driver/SQL/Query/Truncate.class.php
@@ -2,18 +2,20 @@
 
 namespace Driver\SQL\Query;
 
+use Driver\SQL\SQL;
+
 class Truncate extends Query {
 
   private string $tableName;
 
-  public function __construct($sql, $name) {
+  public function __construct(SQL $sql, string $name) {
     parent::__construct($sql);
     $this->tableName = $name;
   }
 
-  public function execute() {
+  public function execute(): bool {
     return $this->sql->executeTruncate($this);
   }
 
-  public function getTable() { return $this->tableName; }
+  public function getTable(): string { return $this->tableName; }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Query/Update.class.php b/core/Driver/SQL/Query/Update.class.php
index e69a4f3..5727512 100644
--- a/core/Driver/SQL/Query/Update.class.php
+++ b/core/Driver/SQL/Query/Update.class.php
@@ -3,6 +3,7 @@
 namespace Driver\SQL\Query;
 
 use Driver\SQL\Condition\CondOr;
+use Driver\SQL\SQL;
 
 class Update extends Query {
 
@@ -10,28 +11,28 @@ class Update extends Query {
   private string $table;
   private array $conditions;
 
-  public function __construct($sql, $table) {
+  public function __construct(SQL $sql, string $table) {
     parent::__construct($sql);
     $this->values = array();
     $this->table = $table;
     $this->conditions = array();
   }
 
-  public function where(...$conditions) {
+  public function where(...$conditions): Update {
     $this->conditions[] = (count($conditions) === 1 ? $conditions : new CondOr($conditions));
     return $this;
   }
 
-  public function set($key, $val) {
+  public function set(string $key, $val): Update {
     $this->values[$key] = $val;
     return $this;
   }
 
-  public function execute() {
+  public function execute(): bool {
     return $this->sql->executeUpdate($this);
   }
 
-  public function getTable() { return $this->table; }
-  public function getConditions() { return $this->conditions; }
-  public function getValues() { return $this->values; }
+  public function getTable(): string { return $this->table; }
+  public function getConditions(): array { return $this->conditions; }
+  public function getValues(): array { return $this->values; }
 }
\ No newline at end of file
diff --git a/core/Driver/SQL/Strategy/UpdateStrategy.class.php b/core/Driver/SQL/Strategy/UpdateStrategy.class.php
index 9084979..6044415 100644
--- a/core/Driver/SQL/Strategy/UpdateStrategy.class.php
+++ b/core/Driver/SQL/Strategy/UpdateStrategy.class.php
@@ -12,9 +12,11 @@ class UpdateStrategy extends Strategy {
     $this->values = $values;
   }
 
-  public function getConflictingColumns() {
+  public function getConflictingColumns(): array {
     return $this->conflictingColumns;
   }
 
-  public function getValues() { return $this->values; }
+  public function getValues(): array {
+    return $this->values;
+  }
 }
\ No newline at end of file
diff --git a/core/Elements/EmptyHead.class.php b/core/Elements/EmptyHead.class.php
index 9495edb..2b877c0 100644
--- a/core/Elements/EmptyHead.class.php
+++ b/core/Elements/EmptyHead.class.php
@@ -11,16 +11,16 @@ class EmptyHead extends Head {
   protected function initSources() {
   }
 
-  protected function initMetas() {
+  protected function initMetas(): array {
     return array(
     );
   }
 
-  protected function initRawFields() {
+  protected function initRawFields(): array {
     return array();
   }
 
-  protected function initTitle() {
+  protected function initTitle(): string {
     return "";
   }
 }
\ No newline at end of file
diff --git a/core/Elements/Head.class.php b/core/Elements/Head.class.php
index 383c2e2..3a03e97 100644
--- a/core/Elements/Head.class.php
+++ b/core/Elements/Head.class.php
@@ -24,9 +24,9 @@ abstract class Head extends View {
   }
 
   protected abstract function initSources();
-  protected abstract function initMetas();
-  protected abstract function initRawFields();
-  protected abstract function initTitle();
+  protected abstract function initMetas(): array;
+  protected abstract function initRawFields(): array;
+  protected abstract function initTitle(): string;
 
   protected function init() {
     $this->keywords = array();
diff --git a/core/Elements/SimpleBody.class.php b/core/Elements/SimpleBody.class.php
index 87f8712..171efce 100644
--- a/core/Elements/SimpleBody.class.php
+++ b/core/Elements/SimpleBody.class.php
@@ -3,14 +3,15 @@
 namespace Elements;
 
 abstract class SimpleBody extends Body {
+
   public function __construct($document) {
     parent::__construct($document);
   }
 
-  public function getCode() {
+  public function getCode(): string {
     $content = $this->getContent();
     return parent::getCode() . "<body>$content</body>";
   }
 
-  protected abstract function getContent();
+  protected abstract function getContent(): string;
 }
\ No newline at end of file
diff --git a/core/Elements/View.class.php b/core/Elements/View.class.php
index b6efbb9..0cf961c 100644
--- a/core/Elements/View.class.php
+++ b/core/Elements/View.class.php
@@ -7,23 +7,25 @@ abstract class View extends StaticView {
   private Document $document;
   private bool $loadView;
   protected bool $searchable;
-  protected string $reference;
   protected string $title;
   protected array $langModules;
 
-  public function __construct(Document $document, $loadView = true) {
+  public function __construct(Document $document, bool $loadView = true) {
     $this->document = $document;
     $this->searchable = false;
-    $this->reference = "";
     $this->title = "Untitled View";
     $this->langModules = array();
     $this->loadView = $loadView;
   }
 
-  public function getTitle() { return $this->title; }
-  public function getDocument() { return $this->document; }
-  public function isSearchable() { return $this->searchable; }
-  public function getReference() { return $this->reference; }
+  public function getTitle(): string { return $this->title; }
+  public function getDocument(): Document { return $this->document; }
+  public function isSearchable(): bool { return $this->searchable; }
+
+  public function getSiteName(): string {
+    // what a chain lol
+    return $this->getDocument()->getUser()->getConfiguration()->getSettings()->getSiteName();
+  }
 
   protected function load(string $viewClass) : string {
     try {
@@ -50,7 +52,7 @@ abstract class View extends StaticView {
   // Virtual Methods
   public function loadView() { }
 
-  public function getCode() {
+  public function getCode(): string {
 
     // Load translations
     $this->loadLanguageModules();
@@ -64,33 +66,33 @@ abstract class View extends StaticView {
   }
 
   // UI Functions
-  private function createList($items, $tag) {
+  private function createList($items, $tag): string {
     if(count($items) === 0)
       return "<$tag></$tag>";
     else
       return "<$tag><li>" . implode("</li><li>", $items) . "</li></$tag>";
   }
 
-  public function createOrderedList($items=array()) {
+  public function createOrderedList($items=array()): string {
     return $this->createList($items, "ol");
   }
 
-  public function createUnorderedList($items=array()) {
+  public function createUnorderedList($items=array()): string {
     return $this->createList($items, "ul");
   }
 
-  protected function createLink($link, $title=null, $classes="") {
+  protected function createLink($link, $title=null, $classes=""): string {
     if(is_null($title)) $title=$link;
     if(!empty($classes)) $classes = " class=\"$classes\"";
     return "<a href=\"$link\"$classes>$title</a>";
   }
 
-  protected function createExternalLink($link, $title=null) {
+  protected function createExternalLink($link, $title=null): string {
     if(is_null($title)) $title=$link;
     return "<a href=\"$link\" target=\"_blank\" class=\"external\">$title</a>";
   }
 
-  protected function createIcon($icon, $type = "fas", $classes = "") {
+  protected function createIcon($icon, $type = "fas", $classes = ""): string {
     $iconClass = "$type fa-$icon";
 
     if($icon === "spinner" || $icon === "circle-notch")
@@ -102,39 +104,39 @@ abstract class View extends StaticView {
     return "<i class=\"$iconClass\" ></i>";
   }
 
-  protected function createErrorText($text, $id="", $hidden=false) {
+  protected function createErrorText($text, $id="", $hidden=false): string {
     return $this->createStatusText("danger", $text, $id, $hidden);
   }
 
-  protected function createWarningText($text, $id="", $hidden=false) {
+  protected function createWarningText($text, $id="", $hidden=false): string {
     return $this->createStatusText("warning", $text, $id, $hidden);
   }
 
-  protected function createSuccessText($text, $id="", $hidden=false) {
+  protected function createSuccessText($text, $id="", $hidden=false): string {
     return $this->createStatusText("success", $text, $id, $hidden);
   }
 
-  protected function createSecondaryText($text, $id="", $hidden=false) {
+  protected function createSecondaryText($text, $id="", $hidden=false): string {
     return $this->createStatusText("secondary", $text, $id, $hidden);
   }
 
-  protected function createInfoText($text, $id="", $hidden=false) {
+  protected function createInfoText($text, $id="", $hidden=false): string {
     return $this->createStatusText("info", $text, $id, $hidden);
   }
 
-  protected function createStatusText($type, $text, $id="", $hidden=false, $classes="") {
+  protected function createStatusText($type, $text, $id="", $hidden=false, $classes=""): string {
     if(strlen($id) > 0) $id = " id=\"$id\"";
     if($hidden) $classes .= " hidden";
     if(strlen($classes) > 0) $classes = " $classes";
     return "<div class=\"alert alert-$type$hidden$classes\" role=\"alert\"$id>$text</div>";
   }
 
-  protected function createBadge($type, $text) {
+  protected function createBadge($type, $text): string {
     $text = htmlspecialchars($text);
     return "<span class=\"badge badge-$type\">$text</span>";
   }
 
-  protected function createJumbotron(string $content, bool $fluid=false, $class="") {
+  protected function createJumbotron(string $content, bool $fluid=false, $class=""): string {
     $jumbotronClass = "jumbotron" . ($fluid ? "-fluid" : "");
     if (!empty($class)) $jumbotronClass .= " $class";
 
@@ -148,12 +150,12 @@ abstract class View extends StaticView {
       </div>";
   }
 
-  public function createSimpleParagraph(string $content, string $class="") {
+  public function createSimpleParagraph(string $content, string $class=""): string {
     if($class) $class = " class=\"$class\"";
     return "<p$class>$content</p>";
   }
 
-  public function createParagraph($title, $id, $content) {
+  public function createParagraph($title, $id, $content): string {
     $id = replaceCssSelector($id);
     $iconId = urlencode("$id-icon");
     return "
@@ -166,7 +168,7 @@ abstract class View extends StaticView {
       </div>";
   }
 
-  protected function createBootstrapTable($data, string $classes="") {
+  protected function createBootstrapTable($data, string $classes=""): string {
     $classes = empty($classes) ? "" : " $classes";
     $code = "<div class=\"container$classes\">";
     foreach($data as $row) {
diff --git a/core/Objects/User.class.php b/core/Objects/User.class.php
index 2fa2361..e3b3ff8 100644
--- a/core/Objects/User.class.php
+++ b/core/Objects/User.class.php
@@ -3,9 +3,6 @@
 namespace Objects;
 
 use Configuration\Configuration;
-use DateTime;
-use Driver\SQL\Expression\Add;
-use Driver\SQL\Strategy\UpdateStrategy;
 use Exception;
 use External\JWT;
 use Driver\SQL\SQL;
@@ -52,19 +49,19 @@ class User extends ApiObject {
     }
   }
 
-  public function getId() { return $this->uid; }
-  public function isLoggedIn() { return $this->loggedIn; }
-  public function getUsername() { return $this->username; }
-  public function getEmail() { return $this->email; }
-  public function getSQL() { return $this->sql; }
-  public function getLanguage() { return $this->language; }
+  public function getId(): int { return $this->uid; }
+  public function isLoggedIn(): bool { return $this->loggedIn; }
+  public function getUsername(): string { return $this->username; }
+  public function getEmail(): ?string { return $this->email; }
+  public function getSQL(): ?SQL { return $this->sql; }
+  public function getLanguage(): Language { return $this->language; }
   public function setLanguage(Language $language) { $this->language = $language; $language->load(); }
-  public function getSession() { return $this->session; }
-  public function getConfiguration() { return $this->configuration; }
-  public function getGroups() { return $this->groups; }
-  public function hasGroup(int $group) { return isset($this->groups[$group]); }
+  public function getSession(): ?Session { return $this->session; }
+  public function getConfiguration(): Configuration { return $this->configuration; }
+  public function getGroups(): array { return $this->groups; }
+  public function hasGroup(int $group): bool { return isset($this->groups[$group]); }
 
-  public function __debugInfo() {
+  public function __debugInfo(): array {
     $debugInfo = array(
       'loggedIn' => $this->loggedIn,
       'language' => $this->language->getName(),
@@ -78,7 +75,7 @@ class User extends ApiObject {
     return $debugInfo;
   }
 
-  public function jsonSerialize() {
+  public function jsonSerialize(): array {
     if ($this->isLoggedIn()) {
       return array(
         'uid' => $this->uid,
@@ -103,7 +100,7 @@ class User extends ApiObject {
     $this->session = null;
   }
 
-  public function logout() {
+  public function logout(): bool {
     $success = true;
     if($this->loggedIn) {
       $success = $this->session->destroy();
@@ -113,7 +110,7 @@ class User extends ApiObject {
     return $success;
   }
 
-  public function updateLanguage($lang) {
+  public function updateLanguage($lang): bool {
     if($this->sql) {
       $request = new \Api\Language\Set($this);
       return $request->execute(array("langCode" => $lang));
@@ -131,7 +128,13 @@ class User extends ApiObject {
     session_write_close();
   }
 
-  public function readData($userId, $sessionId, $sessionUpdate = true) {
+  /**
+   * @param $userId user's id
+   * @param $sessionId session's id
+   * @param bool $sessionUpdate update session information, including session's lifetime and browser information
+   * @return bool true, if the data could be loaded
+   */
+  public function readData($userId, $sessionId, $sessionUpdate = true): bool {
 
     $res = $this->sql->select("User.name", "User.email",
         "Language.uid as langId", "Language.code as langCode", "Language.name as langName",
@@ -203,10 +206,10 @@ class User extends ApiObject {
     }
   }
 
-  public function createSession($userId, $stayLoggedIn) {
+  public function createSession($userId, $stayLoggedIn): bool {
     $this->uid = $userId;
     $this->session = Session::create($this, $stayLoggedIn);
-    if($this->session) {
+    if ($this->session) {
       $this->loggedIn = true;
       return true;
     }
@@ -214,10 +217,11 @@ class User extends ApiObject {
     return false;
   }
 
-  public function authorize($apiKey) {
+  public function authorize($apiKey): bool {
 
-    if($this->loggedIn)
+    if ($this->loggedIn) {
       return true;
+    }
 
     $res = $this->sql->select("ApiKey.user_id as uid", "User.name", "User.email", "User.confirmed",
       "Language.uid as langId", "Language.code as langCode", "Language.name as langName")
@@ -264,7 +268,7 @@ class User extends ApiObject {
     }
   }
 
-  private function isBot() {
+  private function isBot(): bool {
     if (!isset($_SERVER["HTTP_USER_AGENT"]) || empty($_SERVER["HTTP_USER_AGENT"])) {
       return false;
     }
diff --git a/core/Views/Account/AccountView.class.php b/core/Views/Account/AccountView.class.php
index 126e93e..6c6907d 100644
--- a/core/Views/Account/AccountView.class.php
+++ b/core/Views/Account/AccountView.class.php
@@ -26,7 +26,7 @@ abstract class AccountView extends View {
     }
   }
 
-  public function getCode() {
+  public function getCode(): string {
     $html = parent::getCode();
 
     $content = $this->getAccountContent();
diff --git a/core/Views/Admin/AdminDashboardBody.class.php b/core/Views/Admin/AdminDashboardBody.class.php
index fc5fde4..758b595 100644
--- a/core/Views/Admin/AdminDashboardBody.class.php
+++ b/core/Views/Admin/AdminDashboardBody.class.php
@@ -11,7 +11,7 @@ class AdminDashboardBody extends Body {
     parent::__construct($document);
   }
 
-  public function getCode() {
+  public function getCode(): string {
     $html = parent::getCode();
     $script = new Script(Script::MIME_TEXT_JAVASCRIPT, "/js/admin.min.js");
     $html .= "<body><div class=\"wrapper\" id=\"root\">$script</div></body>";
diff --git a/core/Views/Admin/LoginBody.class.php b/core/Views/Admin/LoginBody.class.php
index b165656..b40285a 100644
--- a/core/Views/Admin/LoginBody.class.php
+++ b/core/Views/Admin/LoginBody.class.php
@@ -24,7 +24,7 @@ class LoginBody extends Body {
     $head->addCSS(Link::ACCOUNT);
   }
 
-  public function getCode() {
+  public function getCode(): string {
     $html = parent::getCode();
 
     $username = L("Username");
diff --git a/core/Views/LanguageFlags.class.php b/core/Views/LanguageFlags.class.php
index 381ef1b..b7e4187 100644
--- a/core/Views/LanguageFlags.class.php
+++ b/core/Views/LanguageFlags.class.php
@@ -56,7 +56,7 @@ class LanguageFlags extends View {
     }
   }
 
-  public function getCode() {
+  public function getCode(): string {
     return implode('', $this->languageFlags);
   }
 }
\ No newline at end of file
diff --git a/core/Views/View404.class.php b/core/Views/View404.class.php
index 7f972d2..d3ebe0f 100644
--- a/core/Views/View404.class.php
+++ b/core/Views/View404.class.php
@@ -6,7 +6,7 @@ use Elements\View;
 
 class View404 extends View {
 
-  public function getCode() {
+  public function getCode(): string {
     return parent::getCode() . "<b>Not found</b>";
   }
 
diff --git a/core/core.php b/core/core.php
index c57da2f..0534622 100644
--- a/core/core.php
+++ b/core/core.php
@@ -1,6 +1,6 @@
 <?php
 
-define("WEBBASE_VERSION", "1.2.1");
+define("WEBBASE_VERSION", "1.2.2");
 
 function getProtocol() {
   return (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https" : "http";