Migrate the function to change the style to a command

Author: Cyperghost

wcfsetup/install/files/lib/command/style/ChangeStyle.class.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace wcf\command\style;
+
+use wcf\data\style\Style;
+use wcf\data\user\UserAction;
+use wcf\event\style\StyleChanged;
+use wcf\system\event\EventHandler;
+use wcf\system\style\StyleHandler;
+use wcf\system\WCF;
+
+/**
+ * Change the style for the current user.
+ *
+ * @author Olaf Braun
+ * @copyright 2001-2025 WoltLab GmbH
+ * @license GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @since 6.3
+ */
+final class ChangeStyle
+{
+    public function __construct(
+        private readonly Style $style
+    ) {}
+
+    public function __invoke(): void
+    {
+        StyleHandler::getInstance()->changeStyle($this->style->styleID);
+        if (StyleHandler::getInstance()->getStyle()->styleID !== $this->style->styleID) {
+            // style could not be changed
+            return;
+        }
+
+        if (WCF::getUser()->userID) {
+            $this->saveUserStyle($this->style->styleID, (bool)$this->style->isDefault);
+        } else {
+            $this->saveGuestStyle($this->style->styleID, (bool)$this->style->isDefault);
+        }
+
+        $event = new StyleChanged($this->style);
+        EventHandler::getInstance()->fire($event);
+    }
+
+    private function saveUserStyle(int $styleID, bool $defaultStyle): void
+    {
+        (new UserAction([WCF::getUser()], 'update', [
+            'data' => [
+                'styleID' => $defaultStyle ? 0 : $styleID,
+            ],
+        ]))->executeAction();
+    }
+
+    private function saveGuestStyle(int $styleID, bool $defaultStyle): void
+    {
+        if ($defaultStyle) {
+            WCF::getSession()->unregister('styleID');
+        } else {
+            WCF::getSession()->register('styleID', $styleID);
+        }
+    }
+}

wcfsetup/install/files/lib/data/style/StyleAction.class.php

@@ -3,10 +3,10 @@
 namespace wcf\data\style;
 
 use ParagonIE\ConstantTime\Hex;
+use wcf\command\style\ChangeStyle;
 use wcf\data\AbstractDatabaseObjectAction;
 use wcf\data\IToggleAction;
 use wcf\data\TDatabaseObjectToggle;
-use wcf\data\user\UserAction;
 use wcf\system\exception\PermissionDeniedException;
 use wcf\system\image\ImageHandler;
 use wcf\system\request\LinkHandler;
@@ -520,6 +520,8 @@ public function copy()
      * Validates parameters to change user style.
      *
      * @return void
+     *
+     * @deprecated 6.3
      */
     public function validateChangeStyle()
     {
@@ -533,27 +535,12 @@ public function validateChangeStyle()
      * Changes user style.
      *
      * @return void
+     *
+     * @deprecated 6.3 Use the `ChangeStyle` command instead.
      */
     public function changeStyle()
     {
-        StyleHandler::getInstance()->changeStyle($this->style->styleID);
-        if (StyleHandler::getInstance()->getStyle()->styleID == $this->style->styleID) {
-            if (WCF::getUser()->userID) {
-                // set this as the permanent style
-                $userAction = new UserAction([WCF::getUser()], 'update', [
-                    'data' => [
-                        'styleID' => $this->style->isDefault ? 0 : $this->style->styleID,
-                    ],
-                ]);
-                $userAction->executeAction();
-            } else {
-                if ($this->style->isDefault) {
-                    WCF::getSession()->unregister('styleID');
-                } else {
-                    WCF::getSession()->register('styleID', $this->style->styleID);
-                }
-            }
-        }
+        (new ChangeStyle($this->style))();
     }
 
     /**

wcfsetup/install/files/lib/event/style/StyleChanged.class.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace wcf\event\style;
+
+use wcf\data\style\Style;
+use wcf\event\IPsr14Event;
+
+/**
+ * Indicates that a style has been changed for the current user.
+ *
+ * @author Olaf Braun
+ * @copyright 2001-2025 WoltLab GmbH
+ * @license GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @since 6.3
+ */
+final class StyleChanged implements IPsr14Event
+{
+    public function __construct(public readonly Style $style) {}
+}