Enum for user role - somehow user page is currently unresponsive. Probably because of previous layout changes

frontend/src/api/dtos/UserDto.ts

@@ -1,9 +1,10 @@
-import { AbstractDto } from "./AbstractDto.ts";
+import {AbstractDto} from "./AbstractDto";
+import {UserRole} from "../enums/UserRole";
 
-export class UserDto extends AbstractDto {
+export interface UserDto extends AbstractDto {
     firstName?: string;
     lastName?: string;
-    userName!: string;
-    email!: string;
-    role?: string;
+    userName: string;
+    email: string;
+    role?: UserRole;
 }

frontend/src/api/enums/UserRole.ts

@@ -0,0 +1,52 @@
+/**
+ * User roles - Frontend version
+ * Content should match backend enum exactly
+ * However, we cannot use a basic enum here as we're using erasableSyntaxOnly.
+ */
+export const UserRole = {
+    USER: "user",
+    ADMIN: "admin",
+} as const;
+
+// Create a type from the values
+export type UserRole = typeof UserRole[keyof typeof UserRole];
+
+/**
+ * Helper functions for UserRole in frontend
+ */
+export const UserRoleHelper = {
+    /**
+     * Get display name for role (German)
+     */
+    getDisplayName(role: UserRole): string {
+        const displayNames: Record<UserRole, string> = {
+            [UserRole.USER]: "Benutzer",
+            [UserRole.ADMIN]: "Administrator",
+        };
+        return displayNames[role];
+    },
+
+    /**
+     * Get all roles with display names for dropdowns
+     */
+    getRoleOptions(): Array<{ value: UserRole; label: string }> {
+        return Object.values(UserRole).map((role) => ({
+            value: role,
+            label: this.getDisplayName(role),
+        }));
+    },
+
+    /**
+     * Check if a string is a valid role
+     */
+    isValidRole(value: string): value is UserRole {
+        return Object.values(UserRole).includes(value as UserRole);
+    },
+
+    /**
+     * Get all role values
+     */
+    getAllRoles(): UserRole[] {
+        return Object.values(UserRole);
+    },
+};

frontend/src/components/basics/SelectField.tsx

@@ -1,18 +1,40 @@
-type SelectFieldProps = {
-    value: string;
-    onChange: (value: string) => void;
-    options: { value: string; label: string }[];
+type SelectFieldProps<T extends string> = {
+    value: T;
+    onChange: (value: T) => void;
+    options: { value: T; label: string }[];
     className?: string;
 };
 
 /**
  * SelectField - A dropdown styled consistently with input fields
+ * Generic component that works with any string-based type (including string literals and enums)
+ *
+ * @example
+ * // With UserRole type
+ * <SelectField<UserRole>
+ *   value={user.role}
+ *   onChange={(role) => setUser({...user, role})}
+ *   options={UserRoleHelper.getRoleOptions()}
+ * />
+ *
+ * @example
+ * // With plain strings
+ * <SelectField<string>
+ *   value={status}
+ *   onChange={setStatus}
+ *   options={[{value: "active", label: "Active"}, {value: "inactive", label: "Inactive"}]}
+ * />
  */
-export default function SelectField({value, onChange, options, className = ''}: SelectFieldProps) {
+export default function SelectField<T extends string>({
+                                                          value,
+                                                          onChange,
+                                                          options,
+                                                          className = ''
+                                                      }: SelectFieldProps<T>) {
     return (
         <select
             value={value}
-            onChange={(e) => onChange(e.target.value)}
+            onChange={(e) => onChange(e.target.value as T)}
             className={`p-2 w-full border rounded-md bg-white border-gray-600 hover:border-blue-800 transition-colors text-gray-600 focus:outline-none focus:border-blue-900 cursor-pointer ${className}`}
         >
             {options.map((option) => (

frontend/src/components/users/UserEditForm.tsx

@@ -6,6 +6,7 @@ import PasswordField from "../basics/PasswordField";
 import ButtonGroupLayout from "../basics/ButtonGroupLayout";
 import TextLinkButton from "../basics/TextLinkButton";
 import SelectField from "../basics/SelectField";
+import {UserRole, UserRoleHelper} from "../../api/enums/UserRole.ts";
 
 type UserEditFormProps = {
     user: UserDto;
@@ -52,10 +53,7 @@ export default function UserEditForm({
     };
 
     // @todo API string
-    const roleOptions = [
-        {value: "user", label: "Benutzer"},
-        {value: "admin", label: "Administrator"},
-    ];
+    const roleOptions = UserRoleHelper.getRoleOptions();
 
     return (
         <div className="px-6 py-2">
@@ -104,8 +102,8 @@ export default function UserEditForm({
                 {isAdmin && (
                     <>
                         <label>Benutzergruppe</label>
-                        <SelectField
-                            value={editedUser.role ?? "user"}
+                        <SelectField<UserRole>
+                            value={editedUser.role ?? UserRole.USER}
                             onChange={(value) =>
                                 setEditedUser({...editedUser, role: value})
                             }

frontend/src/components/users/UserManagementPage.tsx

@@ -17,6 +17,7 @@ import type {UserListResponse} from "../../api/dtos/UserListResponse";
 import UserList from "./UserList";
 import UserEditForm from "./UserEditForm";
 import ErrorPopup from "../basics/ErrorPopup";
+import {UserRole} from "../../api/enums/UserRole.ts";
 
 /**
  * UserManagementPage
@@ -39,8 +40,7 @@ export default function UserManagementPage() {
     const [error, setError] = useState<string | null>(null);
 
     //@todo API enum
-    const adminRole: string = "admin";
-    const isAdmin = currentUser?.role === adminRole;
+    const isAdmin = currentUser?.role === UserRole.ADMIN;
 
     // Load current user and user list (if admin)
     useEffect(() => {
@@ -52,7 +52,7 @@ export default function UserManagementPage() {
             const me = await fetchCurrentUser();
             setCurrentUser(me);
 
-            if (me.role === adminRole) {
+            if (me.role === UserRole.ADMIN) {
                 const userResponse: UserListResponse = await fetchAllUsers();
 
                 // Sort users alphabetically by last name, then first name
@@ -140,7 +140,7 @@ export default function UserManagementPage() {
             firstName: "",
             lastName: "",
             email: "",
-            role: "user",
+            role: UserRole.USER,
         });
     };