fixed reload flash for task picker page

resources/js/guest/hooks/useEventData.ts

@@ -19,11 +19,13 @@ interface UseEventDataResult {
 }
 
 const NO_TOKEN_ERROR_MESSAGE = 'Es wurde kein Einladungscode übergeben.';
+const eventCache = new Map<string, EventData>();
 
 export function useEventData(): UseEventDataResult {
   const { token } = useParams<{ token: string }>();
-  const [event, setEvent] = useState<EventData | null>(null);
-  const [status, setStatus] = useState<EventDataStatus>(token ? 'loading' : 'error');
+  const cachedEvent = token ? eventCache.get(token) ?? null : null;
+  const [event, setEvent] = useState<EventData | null>(cachedEvent);
+  const [status, setStatus] = useState<EventDataStatus>(token ? (cachedEvent ? 'ready' : 'loading') : 'error');
   const [errorMessage, setErrorMessage] = useState<string | null>(token ? null : NO_TOKEN_ERROR_MESSAGE);
   const [errorCode, setErrorCode] = useState<FetchEventErrorCode | null>(token ? null : 'invalid_token');
 
@@ -39,7 +41,10 @@ export function useEventData(): UseEventDataResult {
     let cancelled = false;
 
     const loadEvent = async () => {
+      const cached = eventCache.get(token) ?? null;
+      if (!cached) {
         setStatus('loading');
+      }
       setErrorCode(null);
       setErrorMessage(null);
 
@@ -49,6 +54,7 @@ export function useEventData(): UseEventDataResult {
           return;
         }
 
+        eventCache.set(token, eventData);
         setEvent(eventData);
         setStatus('ready');
       } catch (err) {
@@ -56,6 +62,11 @@ export function useEventData(): UseEventDataResult {
           return;
         }
 
+        if (cached) {
+          setEvent(cached);
+          setStatus('ready');
+          return;
+        }
         setEvent(null);
         setStatus('error');