Enhance event date normalization: Introduce a helper function to standardize date formats for the event form, ensuring consistent input handling. Update event data initialization to utilize this function, improving data integrity and user experience.

src/components/EventForm.vue

@@ -113,6 +113,31 @@ import Multiselect from 'vue-multiselect';
 import { formatTime } from '@/utils/strings';
 import AddImageDialog from '@/components/AddImageDialog.vue';
 
+function normalizeDateForInput(value) {
+  if (!value) return '';
+  if (value instanceof Date && !Number.isNaN(value.getTime())) {
+    const yyyy = value.getFullYear();
+    const mm = String(value.getMonth() + 1).padStart(2, '0');
+    const dd = String(value.getDate()).padStart(2, '0');
+    return `${yyyy}-${mm}-${dd}`;
+  }
+  const raw = String(value).trim();
+  // ISO oder SQL-Format: YYYY-MM-DD...
+  const isoMatch = raw.match(/^(\d{4})-(\d{2})-(\d{2})/);
+  if (isoMatch) {
+    return `${isoMatch[1]}-${isoMatch[2]}-${isoMatch[3]}`;
+  }
+  // Deutsches Format: DD.MM.YYYY
+  const deMatch = raw.match(/^(\d{1,2})\.(\d{1,2})\.(\d{4})$/);
+  if (deMatch) {
+    const dd = String(deMatch[1]).padStart(2, '0');
+    const mm = String(deMatch[2]).padStart(2, '0');
+    const yyyy = deMatch[3];
+    return `${yyyy}-${mm}-${dd}`;
+  }
+  return '';
+}
+
 export default {
   name: 'EventForm',
   components: { Multiselect, AddImageDialog },
@@ -140,7 +165,10 @@ export default {
   },
   data() {
     return {
-      eventData: { ...this.event },
+      eventData: {
+        ...this.event,
+        date: normalizeDateForInput(this.event?.date),
+      },
       selectedEventType: null,
       selectedInstitution: this.event.institution || null,
       selectedEventPlace: this.event.eventPlace || null,
@@ -308,9 +336,7 @@ export default {
     },
     normalizeEventForForm(event) {
       const normalized = { ...(event || {}) };
-      if (typeof normalized.date === 'string') {
-        normalized.date = normalized.date.split('T')[0];
-      }
+      normalized.date = normalizeDateForInput(normalized.date);
       const dayValue = this.extractDayOfWeekValue(normalized.dayOfWeek);
       if (dayValue > -1) {
         const mappedValue = dayValue === 0 ? 7 : dayValue;