display drawer regardless of classes fetch state

lib/drawer/drawer.dart

 import 'package:flutter/material.dart';
 
 import '../context.dart';
+import '../untis/class.dart';
 import 'class_list_item.dart';
 
 class ClassDrawer extends StatefulWidget {
@@ -13,6 +14,8 @@ class ClassDrawer extends StatefulWidget {
 }
 
 class _ClassDrawerState extends State<ClassDrawer> {
+  List<Class> get availableClasses => widget.appContext.classes ?? [];
+
   @override
   void initState() {
     super.initState();
@@ -30,10 +33,10 @@ class _ClassDrawerState extends State<ClassDrawer> {
     return Drawer(
       child: ListView.builder(
         itemBuilder: (context, index) {
-          final cls = widget.appContext.classes!.elementAt(index);
+          final cls = availableClasses.elementAt(index);
           return ClassListItem(cls: cls, appContext: widget.appContext);
         },
-        itemCount: widget.appContext.classes!.length,
+        itemCount: availableClasses.length,
       ),
     );
   }

lib/main.dart

@@ -123,9 +123,7 @@ class _MyHomePageState extends State<MyHomePage> {
       appBar: AppBar(
         title: const Text(appName),
       ),
-      drawer: appContext.profile.value == null
-          ? null
-          : ClassDrawer(appContext: appContext),
+      drawer: ClassDrawer(appContext: appContext),
       body: Column(
         children: [
           Toolbar(appContext: appContext),