diff --git a/Controller/ApiController.php b/Controller/ApiController.php
index 0b0b369..f38fcba 100755
--- a/Controller/ApiController.php
+++ b/Controller/ApiController.php
@@ -61,7 +61,7 @@ final class ApiController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return void
      *
@@ -69,7 +69,7 @@ final class ApiController extends Controller
      *
      * @since 1.0.0
      */
-    public function apiResourceRender(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    public function apiResourceRender(RequestAbstract $request, ResponseAbstract $response, array $data = []) : void
     {
         /** @var \Modules\OnlineResourceWatcher\Models\Resource $resource */
         $resource = ResourceMapper::get()
@@ -147,7 +147,7 @@ final class ApiController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return void
      *
@@ -155,7 +155,7 @@ final class ApiController extends Controller
      *
      * @since 1.0.0
      */
-    public function apiResourceCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    public function apiResourceCreate(RequestAbstract $request, ResponseAbstract $response, array $data = []) : void
     {
         if (!empty($val = $this->validateResourceCreate($request))) {
             $response->header->status = RequestStatusCode::R_400;
@@ -201,7 +201,7 @@ final class ApiController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return void
      *
@@ -209,7 +209,7 @@ final class ApiController extends Controller
      *
      * @since 1.0.0
      */
-    public function apiCheckResources(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    public function apiCheckResources(RequestAbstract $request, ResponseAbstract $response, array $data = []) : void
     {
         /** @var Resource[] $resources */
         $resources = ResourceMapper::getAll()
@@ -229,13 +229,13 @@ final class ApiController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return void
      *
      * @since 1.0.0
      */
-    public function informUsers(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    public function informUsers(RequestAbstract $request, ResponseAbstract $response, array $data = []) : void
     {
         $dateTime = new \DateTime('now');
         $dateTime = $dateTime->modify('-1 hour');
@@ -721,7 +721,7 @@ final class ApiController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return void
      *
@@ -729,7 +729,7 @@ final class ApiController extends Controller
      *
      * @since 1.0.0
      */
-    public function apiResourceUpdate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    public function apiResourceUpdate(RequestAbstract $request, ResponseAbstract $response, array $data = []) : void
     {
         if (!empty($val = $this->validateResourceUpdate($request))) {
             $response->data['resource_create'] = new FormValidation($val);
@@ -797,7 +797,7 @@ final class ApiController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return void
      *
@@ -805,7 +805,7 @@ final class ApiController extends Controller
      *
      * @since 1.0.0
      */
-    public function apiResourceGet(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    public function apiResourceGet(RequestAbstract $request, ResponseAbstract $response, array $data = []) : void
     {
     }
 
@@ -814,7 +814,7 @@ final class ApiController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return void
      *
@@ -822,7 +822,7 @@ final class ApiController extends Controller
      *
      * @since 1.0.0
      */
-    public function apiResourceDelete(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    public function apiResourceDelete(RequestAbstract $request, ResponseAbstract $response, array $data = []) : void
     {
         if (!empty($val = $this->validateResourceDelete($request))) {
             $response->data['resource_create'] = new FormValidation($val);
@@ -872,7 +872,7 @@ final class ApiController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return void
      *
@@ -880,7 +880,7 @@ final class ApiController extends Controller
      *
      * @since 1.0.0
      */
-    public function apiInformCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    public function apiInformCreate(RequestAbstract $request, ResponseAbstract $response, array $data = []) : void
     {
         if (!empty($val = $this->validateInformCreate($request))) {
             $response->header->status = RequestStatusCode::R_400;
@@ -950,7 +950,7 @@ final class ApiController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return void
      *
@@ -958,7 +958,7 @@ final class ApiController extends Controller
      *
      * @since 1.0.0
      */
-    public function apiInformDelete(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : void
+    public function apiInformDelete(RequestAbstract $request, ResponseAbstract $response, array $data = []) : void
     {
         if (!empty($val = $this->validateInformDelete($request))) {
             $response->data['resource_create'] = new FormValidation($val);
diff --git a/Controller/BackendController.php b/Controller/BackendController.php
index f721817..50c4f88 100755
--- a/Controller/BackendController.php
+++ b/Controller/BackendController.php
@@ -37,14 +37,14 @@ final class BackendController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return RenderableInterface Returns a renderable object
      *
      * @since 1.0.0
      * @codeCoverageIgnore
      */
-    public function viewResourceList(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : RenderableInterface
+    public function viewResourceList(RequestAbstract $request, ResponseAbstract $response, array $data = []) : RenderableInterface
     {
         $view = new View($this->app->l11nManager, $request, $response);
         $view->setTemplate('/Modules/OnlineResourceWatcher/Theme/Backend/resource-list');
@@ -120,14 +120,14 @@ final class BackendController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return RenderableInterface Returns a renderable object
      *
      * @since 1.0.0
      * @codeCoverageIgnore
      */
-    public function viewResource(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : RenderableInterface
+    public function viewResource(RequestAbstract $request, ResponseAbstract $response, array $data = []) : RenderableInterface
     {
         $view = new View($this->app->l11nManager, $request, $response);
         $view->setTemplate('/Modules/OnlineResourceWatcher/Theme/Backend/resource-single');
@@ -149,14 +149,14 @@ final class BackendController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return RenderableInterface Returns a renderable object
      *
      * @since 1.0.0
      * @codeCoverageIgnore
      */
-    public function viewResourceCreate(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : RenderableInterface
+    public function viewResourceCreate(RequestAbstract $request, ResponseAbstract $response, array $data = []) : RenderableInterface
     {
         return new View($this->app->l11nManager, $request, $response);
     }
@@ -166,14 +166,14 @@ final class BackendController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return RenderableInterface Returns a renderable object
      *
      * @since 1.0.0
      * @codeCoverageIgnore
      */
-    public function viewReportList(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : RenderableInterface
+    public function viewReportList(RequestAbstract $request, ResponseAbstract $response, array $data = []) : RenderableInterface
     {
         return new View($this->app->l11nManager, $request, $response);
     }
@@ -183,14 +183,14 @@ final class BackendController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Generic data
+     * @param array            $data     Generic data
      *
      * @return RenderableInterface Returns a renderable object
      *
      * @since 1.0.0
      * @codeCoverageIgnore
      */
-    public function viewReport(RequestAbstract $request, ResponseAbstract $response, mixed $data = null) : RenderableInterface
+    public function viewReport(RequestAbstract $request, ResponseAbstract $response, array $data = []) : RenderableInterface
     {
         return new View($this->app->l11nManager, $request, $response);
     }