better loading indicators for timetables, talk and files

lib/state/app/modules/chat/bloc/chat_bloc.dart

@@ -1,3 +1,5 @@
+import '../../../../../api/marianumcloud/talk/chat/getChatResponse.dart';
+import '../../../infrastructure/loadableState/loading_error.dart';
 import '../../../infrastructure/utilityWidgets/loadableHydratedBloc/loadable_hydrated_bloc.dart';
 import '../../../infrastructure/utilityWidgets/loadableHydratedBloc/loadable_hydrated_bloc_event.dart';
 import '../repository/chat_repository.dart';
@@ -22,8 +24,11 @@ class ChatBloc extends LoadableHydratedBloc<ChatEvent, ChatState, ChatRepository
   @override
   Future<void> gatherData() async {
     final token = innerState?.currentToken ?? '';
-    if (token.isEmpty) return;
-    _loadChat(token);
+    if (token.isEmpty) {
+      add(DataGathered((s) => s));
+      return;
+    }
+    await _loadChat(token);
   }
 
   void setToken(String token) {
@@ -32,6 +37,7 @@ class ChatBloc extends LoadableHydratedBloc<ChatEvent, ChatState, ChatRepository
       return;
     }
     add(Emit((s) => s.copyWith(currentToken: token, chatResponse: null)));
+    add(RefetchStarted<ChatState>());
     _loadChat(token);
   }
 
@@ -41,19 +47,37 @@ class ChatBloc extends LoadableHydratedBloc<ChatEvent, ChatState, ChatRepository
 
   void refresh() {
     final token = innerState?.currentToken ?? '';
-    if (token.isNotEmpty) _loadChat(token);
+    if (token.isEmpty) return;
+    add(RefetchStarted<ChatState>());
+    _loadChat(token);
   }
 
-  void _loadChat(String token) {
+  Future<void> _loadChat(String token) async {
     final requestStart = DateTime.now();
     _lastTokenSet = requestStart;
-    repo.data.getChat(
-      token: token,
-      onUpdate: (data) {
-        if (_lastTokenSet.isAfter(requestStart)) return;
-        if ((innerState?.currentToken ?? '') != token) return;
-        add(DataGathered((s) => s.copyWith(chatResponse: data)));
-      },
-    );
+
+    Object? capturedError;
+    GetChatResponse? response;
+    try {
+      response = await repo.data.getChat(
+        token: token,
+        onError: (e) => capturedError = e,
+      );
+    } catch (e) {
+      capturedError = e;
+    }
+
+    if (_lastTokenSet.isAfter(requestStart)) return;
+    if ((innerState?.currentToken ?? '') != token) return;
+
+    if (response != null) {
+      add(DataGathered((s) => s.copyWith(chatResponse: response)));
+    }
+    if (capturedError != null) {
+      add(Error(LoadingError(
+        message: capturedError.toString(),
+        allowRetry: true,
+      )));
+    }
   }
 }

lib/state/app/modules/chat/dataProvider/chat_data_provider.dart

@@ -2,10 +2,26 @@ import '../../../../../api/marianumcloud/talk/chat/getChatCache.dart';
 import '../../../../../api/marianumcloud/talk/chat/getChatResponse.dart';
 
 class ChatDataProvider {
-  void getChat({
+  Future<GetChatResponse> getChat({
     required String token,
-    required void Function(GetChatResponse data) onUpdate,
-  }) {
-    GetChatCache(chatToken: token, onUpdate: onUpdate);
+    void Function(GetChatResponse data)? onUpdate,
+    void Function(Object)? onError,
+  }) async {
+    GetChatResponse? latest;
+    Object? capturedError;
+    final cache = GetChatCache(
+      chatToken: token,
+      onUpdate: (data) {
+        latest = data;
+        onUpdate?.call(data);
+      },
+      onError: (e) {
+        capturedError = e;
+        onError?.call(e);
+      },
+    );
+    await cache.ready;
+    if (latest != null) return latest!;
+    throw capturedError ?? Exception('No data and no error from getChat');
   }
 }