diff --git a/public/index.php b/public/index.php
index 509c7ba..e58da6f 100644
--- a/public/index.php
+++ b/public/index.php
@@ -26,8 +26,9 @@ if ($match !== null) {
     }
 
     if ($method === 'post' && Container::$request->post('anti_csrf_token') !== Container::$request->session()->get('anti_csrf_token')) {
+        $content = new MapGuesser\Response\JsonContent(['error' => 'no_valid_anti_csrf_token']);
         header('Content-Type: text/html; charset=UTF-8', true, 403);
-        echo json_encode(['error' => 'no_valid_anti_csrf_token']);
+        $content->render();
         return;
     }
 
diff --git a/src/Controller/GameController.php b/src/Controller/GameController.php
index 0027e2c..7bcc2dd 100644
--- a/src/Controller/GameController.php
+++ b/src/Controller/GameController.php
@@ -21,15 +21,15 @@ class GameController
     public function getGame(): IContent
     {
         $mapId = (int) $this->request->query('mapId');
-        $data = $this->prepareGame($mapId);
-        return new HtmlContent('game', $data);
+
+        return new HtmlContent('game', $this->prepareGame($mapId));
     }
 
     public function getGameJson(): IContent
     {
         $mapId = (int) $this->request->query('mapId');
-        $data = $this->prepareGame($mapId);
-        return new JsonContent($data);
+
+        return new JsonContent($this->prepareGame($mapId));
     }
 
     private function prepareGame(int $mapId)
diff --git a/src/Controller/GameFlowController.php b/src/Controller/GameFlowController.php
index e1b10fa..c7cf95b 100644
--- a/src/Controller/GameFlowController.php
+++ b/src/Controller/GameFlowController.php
@@ -29,8 +29,7 @@ class GameFlowController
         $session = $this->request->session();
 
         if (!($state = $session->get('state')) || $state['mapId'] !== $mapId) {
-            $data = ['error' => 'no_session_found'];
-            return new JsonContent($data);
+            return new JsonContent(['error' => 'no_session_found']);
         }
 
         if (count($state['rounds']) === 0) {
@@ -79,8 +78,7 @@ class GameFlowController
         $session = $this->request->session();
 
         if (!($state = $session->get('state')) || $state['mapId'] !== $mapId) {
-            $data = ['error' => 'no_session_found'];
-            return new JsonContent($data);
+            return new JsonContent(['error' => 'no_session_found']);
         }
 
         $last = $state['rounds'][count($state['rounds']) - 1];
@@ -119,7 +117,7 @@ class GameFlowController
 
         $session->set('state', $state);
 
-        $data = [
+        return new JsonContent([
             'result' => [
                 'position' => $position->toArray(),
                 'distance' => $distance,
@@ -127,8 +125,7 @@ class GameFlowController
             ],
             'panoId' => $panoId,
             'pov' => $pov
-        ];
-        return new JsonContent($data);
+        ]);
     }
 
     private function addNewRoundToState(&$state, Place $place, array $placesWithoutPano): void
diff --git a/src/Controller/HomeController.php b/src/Controller/HomeController.php
index a80c1ed..6e2a2f2 100644
--- a/src/Controller/HomeController.php
+++ b/src/Controller/HomeController.php
@@ -24,7 +24,6 @@ class HomeController
     {
         // session starts with the request, this method just sends valid data to the client
 
-        $data = ['antiCsrfToken' => $this->request->session()->get('anti_csrf_token')];
-        return new JsonContent($data);
+        return new JsonContent(['antiCsrfToken' => $this->request->session()->get('anti_csrf_token')]);
     }
 }
diff --git a/src/Controller/LoginController.php b/src/Controller/LoginController.php
index bc130c7..ac0a25e 100644
--- a/src/Controller/LoginController.php
+++ b/src/Controller/LoginController.php
@@ -46,8 +46,7 @@ class LoginController
             return new Redirect(\Container::$routeCollection->getRoute('index')->generateLink(), IRedirect::TEMPORARY);
         }
 
-        $data = [];
-        return new HtmlContent('login/login', $data);
+        return new HtmlContent('login/login');
     }
 
     public function getGoogleLoginRedirect(): IRedirect
@@ -57,7 +56,10 @@ class LoginController
         $this->request->session()->set('oauth_state', $state);
 
         $oAuth = new GoogleOAuth(new Request());
-        $url = $oAuth->getDialogUrl($state, $this->request->getBase() . '/' . \Container::$routeCollection->getRoute('login-google-action')->generateLink());
+        $url = $oAuth->getDialogUrl(
+            $state,
+            $this->request->getBase() . '/' . \Container::$routeCollection->getRoute('login-google-action')->generateLink()
+        );
 
         return new Redirect($url, IRedirect::TEMPORARY);
     }
@@ -81,8 +83,7 @@ class LoginController
 
     public function getSignupSuccess(): IContent
     {
-        $data = [];
-        return new HtmlContent('login/signup_success', $data);
+        return new HtmlContent('login/signup_success');
     }
 
     public function getSignupWithGoogleForm()
@@ -99,8 +100,7 @@ class LoginController
 
         $user = $this->userRepository->getByEmail($userData['email']);
 
-        $data = ['found' => $user !== null, 'email' => $userData['email']];
-        return new HtmlContent('login/google_signup', $data);
+        return new HtmlContent('login/google_signup', ['found' => $user !== null, 'email' => $userData['email']]);
     }
 
     public function getRequestPasswordResetForm()
@@ -109,8 +109,7 @@ class LoginController
             return new Redirect(\Container::$routeCollection->getRoute('index')->generateLink(), IRedirect::TEMPORARY);
         }
 
-        $data = ['email' => $this->request->query('email')];
-        return new HtmlContent('login/password_reset_request', $data);
+        return new HtmlContent('login/password_reset_request', ['email' => $this->request->query('email')]);
     }
 
     public function getRequestPasswordResetSuccess(): IContent
@@ -128,54 +127,67 @@ class LoginController
         $resetter = $this->userPasswordResetterRepository->getByToken($token);
 
         if ($resetter === null || $resetter->getExpiresDate() < new DateTime()) {
-            $data = ['success' => false];
-            return new HtmlContent('login/reset_password', $data);
+            return new HtmlContent('login/reset_password', ['success' => false]);
         }
 
         $user = $this->userRepository->getById($resetter->getUserId());
 
-        $data = ['success' => true, 'token' => $token, 'email' => $user->getEmail()];
-        return new HtmlContent('login/reset_password', $data);
+        return new HtmlContent('login/reset_password', ['success' => true, 'token' => $token, 'email' => $user->getEmail()]);
     }
 
     public function login(): IContent
     {
         if ($this->request->user() !== null) {
-            $data = ['success' => true];
-            return new JsonContent($data);
+            return new JsonContent(['success' => true]);
         }
 
         $user = $this->userRepository->getByEmail($this->request->post('email'));
 
         if ($user === null) {
             if (strlen($this->request->post('password')) < 6) {
-                $data = ['error' => ['errorText' => 'The given password is too short. Please choose a password that is at least 6 characters long!']];
-                return new JsonContent($data);
+                return new JsonContent([
+                    'error' => [
+                        'errorText' => 'The given password is too short. Please choose a password that is at least 6 characters long!'
+                    ]
+                ]);
             }
 
             $tmpUser = new User();
             $tmpUser->setPlainPassword($this->request->post('password'));
 
-            $this->request->session()->set('tmp_user_data', ['email' => $this->request->post('email'), 'password_hashed' => $tmpUser->getPassword()]);
+            $this->request->session()->set('tmp_user_data', [
+                'email' => $this->request->post('email'),
+                'password_hashed' => $tmpUser->getPassword()
+            ]);
 
-            $data = ['redirect' => ['target' => '/' . \Container::$routeCollection->getRoute('signup')->generateLink()]];
-            return new JsonContent($data);
+            return new JsonContent([
+                'redirect' => [
+                    'target' => '/' . \Container::$routeCollection->getRoute('signup')->generateLink()
+                ]
+            ]);
         }
 
         if (!$user->getActive()) {
-            $data = ['error' => ['errorText' => 'User found with the given email address, but the account is not activated. Please check your email and click on the activation link!']];
-            return new JsonContent($data);
+            return new JsonContent([
+                'error' => [
+                    'errorText' => 'User found with the given email address, but the account is not activated. ' .
+                        'Please check your email and click on the activation link!'
+                ]
+            ]);
         }
 
         if (!$user->checkPassword($this->request->post('password'))) {
-            $data = ['error' => ['errorText' => 'The given password is wrong. You can <a href="/password/requestReset?email=' . urlencode($user->getEmail()) . '" title="Request password reset">request password reset</a>!']];
-            return new JsonContent($data);
+            return new JsonContent([
+                'error' => [
+                    'errorText' => 'The given password is wrong. You can <a href="/password/requestReset?email=' .
+                        urlencode($user->getEmail()) . '" title="Request password reset">request password reset</a>!'
+                ]
+            ]);
         }
 
         $this->request->setUser($user);
 
-        $data = ['success' => true];
-        return new JsonContent($data);
+        return new JsonContent(['success' => true]);
     }
 
     public function loginWithGoogle()
@@ -185,24 +197,24 @@ class LoginController
         }
 
         if ($this->request->query('state') !== $this->request->session()->get('oauth_state')) {
-            $data = [];
-            return new HtmlContent('login/google_login', $data);
+            return new HtmlContent('login/google_login');
         }
 
         $oAuth = new GoogleOAuth(new Request());
-        $tokenData = $oAuth->getToken($this->request->query('code'), $this->request->getBase() . '/' . \Container::$routeCollection->getRoute('login-google-action')->generateLink());
+        $tokenData = $oAuth->getToken(
+            $this->request->query('code'),
+            $this->request->getBase() . '/' . \Container::$routeCollection->getRoute('login-google-action')->generateLink()
+        );
 
         if (!isset($tokenData['id_token'])) {
-            $data = [];
-            return new HtmlContent('login/google_login', $data);
+            return new HtmlContent('login/google_login');
         }
 
         $jwtParser = new JwtParser($tokenData['id_token']);
         $userData = $jwtParser->getPayload();
 
         if (!$userData['email_verified']) {
-            $data = [];
-            return new HtmlContent('login/google_login', $data);
+            return new HtmlContent('login/google_login');
         }
 
         $user = $this->userRepository->getByGoogleSub($userData['sub']);
@@ -228,8 +240,7 @@ class LoginController
     public function signup(): IContent
     {
         if ($this->request->user() !== null) {
-            $data = ['redirect' => ['target' => '/' . \Container::$routeCollection->getRoute('home')->generateLink()]];
-            return new JsonContent($data);
+            return new JsonContent(['redirect' => ['target' => '/' . \Container::$routeCollection->getRoute('home')->generateLink()]]);
         }
 
         $user = $this->userRepository->getByEmail($this->request->post('email'));
@@ -237,22 +248,31 @@ class LoginController
         if ($user !== null) {
             if ($user->getActive()) {
                 if (!$user->checkPassword($this->request->post('password'))) {
-                    $data = ['error' => ['errorText' => 'There is a user already registered with the given email address, but the given password is wrong. You can <a href="/password/requestReset?email=' . urlencode($user->getEmail()) . '" title="Request password reset">request password reset</a>!']];
-                    return new JsonContent($data);
+                    return new JsonContent([
+                        'error' => [
+                            'errorText' => 'There is a user already registered with the given email address, ' .
+                                'but the given password is wrong. You can <a href="/password/requestReset?email=' .
+                                urlencode($user->getEmail()) . '" title="Request password reset">request password reset</a>!'
+                        ]
+                    ]);
                 }
 
                 $this->request->setUser($user);
 
                 $data = ['redirect' => ['target' => '/' . \Container::$routeCollection->getRoute('index')->generateLink()]];
             } else {
-                $data = ['error' => ['errorText' => 'There is a user already registered with the given email address. Please check your email and click on the activation link!']];
+                $data = [
+                    'error' => [
+                        'errorText' => 'There is a user already registered with the given email address. ' .
+                            'Please check your email and click on the activation link!'
+                    ]
+                ];
             }
             return new JsonContent($data);
         }
 
         if (filter_var($this->request->post('email'), FILTER_VALIDATE_EMAIL) === false) {
-            $data = ['error' => ['errorText' => 'The given email address is not valid.']];
-            return new JsonContent($data);
+            return new JsonContent(['error' => ['errorText' => 'The given email address is not valid.']]);
         }
 
         if ($this->request->session()->has('tmp_user_data')) {
@@ -262,18 +282,19 @@ class LoginController
             $tmpUser->setPassword($tmpUserData['password_hashed']);
 
             if (!$tmpUser->checkPassword($this->request->post('password'))) {
-                $data = ['error' => ['errorText' => 'The given passwords do not match.']];
-                return new JsonContent($data);
+                return new JsonContent(['error' => ['errorText' => 'The given passwords do not match.']]);
             }
         } else {
             if (strlen($this->request->post('password')) < 6) {
-                $data = ['error' => ['errorText' => 'The given password is too short. Please choose a password that is at least 6 characters long!']];
-                return new JsonContent($data);
+                return new JsonContent([
+                    'error' => [
+                        'errorText' => 'The given password is too short. Please choose a password that is at least 6 characters long!'
+                    ]
+                ]);
             }
 
             if ($this->request->post('password') !== $this->request->post('password_confirm')) {
-                $data = ['error' => ['errorText' => 'The given passwords do not match.']];
-                return new JsonContent($data);
+                return new JsonContent(['error' => ['errorText' => 'The given passwords do not match.']]);
             }
         }
 
@@ -299,15 +320,13 @@ class LoginController
 
         $this->request->session()->delete('tmp_user_data');
 
-        $data = ['success' => true];
-        return new JsonContent($data);
+        return new JsonContent(['success' => true]);
     }
 
     public function signupWithGoogle(): IContent
     {
         if ($this->request->user() !== null) {
-            $data = ['success' => true];
-            return new JsonContent($data);
+            return new JsonContent(['success' => true]);
         }
 
         $userData = $this->request->session()->get('google_user_data');
@@ -335,24 +354,21 @@ class LoginController
         $this->request->session()->delete('google_user_data');
         $this->request->setUser($user);
 
-        $data = ['success' => true];
-        return new JsonContent($data);
+        return new JsonContent(['success' => true]);
     }
 
     public function resetSignup(): IContent
     {
         $this->request->session()->delete('tmp_user_data');
 
-        $data = ['success' => true];
-        return new JsonContent($data);
+        return new JsonContent(['success' => true]);
     }
 
     public function resetGoogleSignup(): IContent
     {
         $this->request->session()->delete('google_user_data');
 
-        $data = ['success' => true];
-        return new JsonContent($data);
+        return new JsonContent(['success' => true]);
     }
 
     public function activate()
@@ -364,8 +380,7 @@ class LoginController
         $confirmation = $this->userConfirmationRepository->getByToken($this->request->query('token'));
 
         if ($confirmation === null) {
-            $data = [];
-            return new HtmlContent('login/activate', $data);
+            return new HtmlContent('login/activate');
         }
 
         \Container::$dbConnection->startTransaction();
@@ -393,8 +408,7 @@ class LoginController
         $confirmation = $this->userConfirmationRepository->getByToken($this->request->query('token'));
 
         if ($confirmation === null) {
-            $data = ['success' => false];
-            return new HtmlContent('login/cancel', $data);
+            return new HtmlContent('login/cancel', ['success' => false]);
         }
 
         \Container::$dbConnection->startTransaction();
@@ -407,27 +421,36 @@ class LoginController
 
         \Container::$dbConnection->commit();
 
-        $data = ['success' => true];
-        return new HtmlContent('login/cancel', $data);
+        return new HtmlContent('login/cancel', ['success' => true]);
     }
 
     public function requestPasswordReset(): IContent
     {
         if ($this->request->user() !== null) {
-            $data = ['redirect' => ['target' => '/' . \Container::$routeCollection->getRoute('home')->generateLink()]];
-            return new JsonContent($data);
+            return new JsonContent([
+                'redirect' => [
+                    'target' => '/' . \Container::$routeCollection->getRoute('home')->generateLink()
+                ]
+            ]);
         }
 
         $user = $this->userRepository->getByEmail($this->request->post('email'));
 
         if ($user === null) {
-            $data = ['error' => ['errorText' => 'No user found with the given email address. You can <a href="/signup" title="Sign up">sign up</a>!']];
-            return new JsonContent($data);
+            return new JsonContent([
+                'error' => [
+                    'errorText' => 'No user found with the given email address. You can <a href="/signup" title="Sign up">sign up</a>!'
+                ]
+            ]);
         }
 
         if (!$user->getActive()) {
-            $data = ['error' => ['errorText' => 'User found with the given email address, but the account is not activated. Please check your email and click on the activation link!']];
-            return new JsonContent($data);
+            return new JsonContent([
+                'error' => [
+                    'errorText' => 'User found with the given email address, but the account is not activated. ' .
+                        'Please check your email and click on the activation link!'
+                ]
+            ]);
         }
 
         $token = bin2hex(random_bytes(16));
@@ -442,34 +465,41 @@ class LoginController
 
         $this->sendPasswordResetEmail($user->getEmail(), $token, $expires);
 
-        $data = ['success' => true];
-        return new JsonContent($data);
+        return new JsonContent(['success' => true]);
     }
 
 
     public function resetPassword(): IContent
     {
         if ($this->request->user() !== null) {
-            $data = ['redirect' => ['target' => '/' . \Container::$routeCollection->getRoute('home')->generateLink()]];
-            return new JsonContent($data);
+            return new JsonContent([
+                'redirect' => [
+                    'target' => '/' . \Container::$routeCollection->getRoute('home')->generateLink()
+                ]
+            ]);
         }
 
         $token = $this->request->query('token');
         $resetter = $this->userPasswordResetterRepository->getByToken($token);
 
         if ($resetter === null || $resetter->getExpiresDate() < new DateTime()) {
-            $data = ['redirect' => ['target' => '/' . \Container::$routeCollection->getRoute('password-reset')->generateLink(['token' => $token])]];
-            return new JsonContent($data);
+            return new JsonContent([
+                'redirect' => [
+                    'target' => '/' . \Container::$routeCollection->getRoute('password-reset')->generateLink(['token' => $token])
+                ]
+            ]);
         }
 
         if (strlen($this->request->post('password')) < 6) {
-            $data = ['error' => ['errorText' => 'The given password is too short. Please choose a password that is at least 6 characters long!']];
-            return new JsonContent($data);
+            return new JsonContent([
+                'error' => [
+                    'errorText' => 'The given password is too short. Please choose a password that is at least 6 characters long!'
+                ]
+            ]);
         }
 
         if ($this->request->post('password') !== $this->request->post('password_confirm')) {
-            $data = ['error' => ['errorText' => 'The given passwords do not match.']];
-            return new JsonContent($data);
+            return new JsonContent(['error' => ['errorText' => 'The given passwords do not match.']]);
         }
 
         \Container::$dbConnection->startTransaction();
@@ -485,8 +515,7 @@ class LoginController
 
         $this->request->setUser($user);
 
-        $data = ['success' => true];
-        return new JsonContent($data);
+        return new JsonContent(['success' => true]);
     }
 
     private function sendConfirmationEmail(string $email, string $token): void
@@ -496,8 +525,10 @@ class LoginController
         $mail->setSubject('Welcome to ' . $_ENV['APP_NAME'] . ' - Activate your account');
         $mail->setBodyFromTemplate('signup', [
             'EMAIL' => $email,
-            'ACTIVATE_LINK' => $this->request->getBase() . '/' . \Container::$routeCollection->getRoute('signup.activate')->generateLink(['token' => $token]),
-            'CANCEL_LINK' => $this->request->getBase() . '/' . \Container::$routeCollection->getRoute('signup.cancel')->generateLink(['token' => $token]),
+            'ACTIVATE_LINK' => $this->request->getBase() . '/' .
+                \Container::$routeCollection->getRoute('signup.activate')->generateLink(['token' => $token]),
+            'CANCEL_LINK' => $this->request->getBase() . '/' .
+                \Container::$routeCollection->getRoute('signup.cancel')->generateLink(['token' => $token]),
         ]);
         $mail->send();
     }
@@ -520,7 +551,8 @@ class LoginController
         $mail->setSubject($_ENV['APP_NAME'] . ' - Password reset');
         $mail->setBodyFromTemplate('password-reset', [
             'EMAIL' => $email,
-            'RESET_LINK' => $this->request->getBase() . '/' . \Container::$routeCollection->getRoute('password-reset')->generateLink(['token' => $token]),
+            'RESET_LINK' => $this->request->getBase() . '/' .
+                \Container::$routeCollection->getRoute('password-reset')->generateLink(['token' => $token]),
             'EXPIRES' => $expires->format('Y-m-d H:i:s T')
         ]);
         $mail->send();
diff --git a/src/Controller/MapAdminController.php b/src/Controller/MapAdminController.php
index 0d7ad02..7f64d0f 100644
--- a/src/Controller/MapAdminController.php
+++ b/src/Controller/MapAdminController.php
@@ -58,8 +58,13 @@ class MapAdminController implements ISecured
             $places = [];
         }
 
-        $data = ['mapId' => $mapId, 'mapName' => $map->getName(), 'mapDescription' => str_replace('<br>', "\n", $map->getDescription()), 'bounds' => $map->getBounds()->toArray(), 'places' => &$places];
-        return new HtmlContent('admin/map_editor', $data);
+        return new HtmlContent('admin/map_editor', [
+            'mapId' => $mapId,
+            'mapName' => $map->getName(),
+            'mapDescription' => str_replace('<br>', "\n", $map->getDescription()),
+            'bounds' => $map->getBounds()->toArray(),
+            'places' => &$places
+        ]);
     }
 
     public function getPlace(): IContent
@@ -68,8 +73,7 @@ class MapAdminController implements ISecured
 
         $place = $this->placeRepository->getById($placeId);
 
-        $data = ['panoId' => $place->getFreshPanoId()];
-        return new JsonContent($data);
+        return new JsonContent(['panoId' => $place->getFreshPanoId()]);
     }
 
     public function saveMap(): IContent
@@ -157,8 +161,7 @@ class MapAdminController implements ISecured
 
         \Container::$dbConnection->commit();
 
-        $data = ['mapId' => $map->getId(), 'added' => $addedIds];
-        return new JsonContent($data);
+        return new JsonContent(['mapId' => $map->getId(), 'added' => $addedIds]);
     }
 
     public function deleteMap()
@@ -175,8 +178,7 @@ class MapAdminController implements ISecured
 
         \Container::$dbConnection->commit();
 
-        $data = ['success' => true];
-        return new JsonContent($data);
+        return new JsonContent(['success' => true]);
     }
 
     private function deletePlaces(Map $map): void
diff --git a/src/Controller/MapsController.php b/src/Controller/MapsController.php
index 932e69e..3c90d56 100644
--- a/src/Controller/MapsController.php
+++ b/src/Controller/MapsController.php
@@ -46,8 +46,10 @@ class MapsController
         }
 
         $user = $this->request->user();
-        $data = ['maps' => $maps, 'isAdmin' => $user !== null && $user->hasPermission(IUser::PERMISSION_ADMIN)];
-        return new HtmlContent('maps', $data);
+        return new HtmlContent('maps', [
+            'maps' => $maps,
+            'isAdmin' => $user !== null && $user->hasPermission(IUser::PERMISSION_ADMIN)
+        ]);
     }
 
     private function formatMapAreaForHuman(float $area): array
diff --git a/src/Controller/UserController.php b/src/Controller/UserController.php
index 9314dd7..83f3c89 100644
--- a/src/Controller/UserController.php
+++ b/src/Controller/UserController.php
@@ -48,8 +48,7 @@ class UserController implements ISecured
          */
         $user = $this->request->user();
 
-        $data = ['user' => $user->toArray()];
-        return new HtmlContent('account/account', $data);
+        return new HtmlContent('account/account', ['user' => $user->toArray()]);
     }
 
     public function getGoogleAuthenticateRedirect(): IRedirect
@@ -82,31 +81,36 @@ class UserController implements ISecured
         $user = $this->request->user();
 
         if ($this->request->query('state') !== $this->request->session()->get('oauth_state')) {
-            $data = ['success' => false];
-            return new HtmlContent('account/google_authenticate', $data);
+            return new HtmlContent('account/google_authenticate', ['success' => false]);
         }
 
         $oAuth = new GoogleOAuth(new Request());
-        $tokenData = $oAuth->getToken($this->request->query('code'), $this->request->getBase() . '/' . \Container::$routeCollection->getRoute('account.googleAuthenticate-action')->generateLink());
+        $tokenData = $oAuth->getToken(
+            $this->request->query('code'),
+            $this->request->getBase() . '/' . \Container::$routeCollection->getRoute('account.googleAuthenticate-action')->generateLink()
+        );
 
         if (!isset($tokenData['id_token'])) {
-            $data = ['success' => false];
-            return new HtmlContent('account/google_authenticate', $data);
+            return new HtmlContent('account/google_authenticate', ['success' => false]);
         }
 
         $jwtParser = new JwtParser($tokenData['id_token']);
         $userData = $jwtParser->getPayload();
 
         if ($userData['sub'] !== $user->getGoogleSub()) {
-            $data = ['success' => false, 'errorText' => 'This Google account is not linked to your account.'];
-            return new HtmlContent('account/google_authenticate', $data);
+            return new HtmlContent('account/google_authenticate', [
+                'success' => false,
+                'errorText' => 'This Google account is not linked to your account.'
+            ]);
         }
 
         $authenticatedWithGoogleUntil = new DateTime('+45 seconds');
         $this->request->session()->set('authenticated_with_google_until', $authenticatedWithGoogleUntil);
 
-        $data = ['success' => true, 'authenticatedWithGoogleUntil' => $authenticatedWithGoogleUntil];
-        return new HtmlContent('account/google_authenticate', $data);
+        return new HtmlContent('account/google_authenticate', [
+            'success' => true,
+            'authenticatedWithGoogleUntil' => $authenticatedWithGoogleUntil
+        ]);
     }
 
     public function getDeleteAccount(): IContent
@@ -116,8 +120,7 @@ class UserController implements ISecured
          */
         $user = $this->request->user();
 
-        $data = ['user' => $user->toArray()];
-        return new HtmlContent('account/delete', $data);
+        return new HtmlContent('account/delete', ['user' => $user->toArray()]);
     }
 
     public function saveAccount(): IContent
@@ -133,19 +136,24 @@ class UserController implements ISecured
             $this->request->post('password'),
             $error
         )) {
-            $data = ['error' => ['errorText' => $error]];
-            return new JsonContent($data);
+            return new JsonContent(['error' => ['errorText' => $error]]);
         }
 
         if (strlen($this->request->post('password_new')) > 0) {
             if (strlen($this->request->post('password_new')) < 6) {
-                $data = ['error' => ['errorText' => 'The given new password is too short. Please choose a password that is at least 6 characters long!']];
-                return new JsonContent($data);
+                return new JsonContent([
+                    'error' => [
+                        'errorText' => 'The given new password is too short. Please choose a password that is at least 6 characters long!'
+                    ]
+                ]);
             }
 
             if ($this->request->post('password_new') !== $this->request->post('password_new_confirm')) {
-                $data = ['error' => ['errorText' => 'The given new passwords do not match.']];
-                return new JsonContent($data);
+                return new JsonContent([
+                    'error' => [
+                        'errorText' => 'The given new passwords do not match.'
+                    ]
+                ]);
             }
 
             $user->setPlainPassword($this->request->post('password_new'));
@@ -155,8 +163,7 @@ class UserController implements ISecured
 
         $this->request->session()->delete('authenticated_with_google_until');
 
-        $data = ['success' => true];
-        return new JsonContent($data);
+        return new JsonContent(['success' => true]);
     }
 
     public function deleteAccount(): IContent
@@ -172,8 +179,7 @@ class UserController implements ISecured
             $this->request->post('password'),
             $error
         )) {
-            $data = ['error' => ['errorText' => $error]];
-            return new JsonContent($data);
+            return new JsonContent(['error' => ['errorText' => $error]]);
         }
 
         \Container::$dbConnection->startTransaction();
@@ -192,8 +198,7 @@ class UserController implements ISecured
 
         $this->request->session()->delete('authenticated_with_google_until');
 
-        $data = ['success' => true];
-        return new JsonContent($data);
+        return new JsonContent(['success' => true]);
     }
 
     private function confirmUserIdentity(User $user, ?DateTime $authenticatedWithGoogleUntil, ?string $password, &$error): bool
diff --git a/src/Interfaces/Response/IContent.php b/src/Interfaces/Response/IContent.php
index fef4842..c93e94b 100644
--- a/src/Interfaces/Response/IContent.php
+++ b/src/Interfaces/Response/IContent.php
@@ -2,7 +2,9 @@
 
 interface IContent
 {
-    public function &getData(): array;
+    public function setData(array $data): void;
+
+    public function getData(): array;
 
     public function render(): void;
 
diff --git a/src/Response/ContentBase.php b/src/Response/ContentBase.php
index 31d0053..10cfafc 100644
--- a/src/Response/ContentBase.php
+++ b/src/Response/ContentBase.php
@@ -6,7 +6,12 @@ abstract class ContentBase implements IContent
 {
     protected array $data;
 
-    public function &getData(): array
+    public function setData(array $data): void
+    {
+        $this->data = $data;
+    }
+
+    public function getData(): array
     {
         return $this->data;
     }
diff --git a/src/Response/HtmlContent.php b/src/Response/HtmlContent.php
index b5c9d6c..377b32e 100644
--- a/src/Response/HtmlContent.php
+++ b/src/Response/HtmlContent.php
@@ -6,10 +6,10 @@ class HtmlContent extends ContentBase
 {
     private string $view;
 
-    public function __construct(string $view, array &$data = [])
+    public function __construct(string $view, array $data = [])
     {
         $this->view = $view;
-        $this->data = &$data;
+        $this->data = $data;
     }
 
     public function render(): void
diff --git a/src/Response/JsonContent.php b/src/Response/JsonContent.php
index c2ecac0..9632328 100644
--- a/src/Response/JsonContent.php
+++ b/src/Response/JsonContent.php
@@ -2,9 +2,9 @@
 
 class JsonContent extends ContentBase
 {
-    public function __construct(array &$data = [])
+    public function __construct(array $data = [])
     {
-        $this->data = &$data;
+        $this->data = $data;
     }
 
     public function render(): void