now shows every empty required field in the save as template dialog

lib/addCam/add_cam_main.dart

@@ -216,7 +216,7 @@ class _AddCamMainState extends State<AddCamMain> {
   }
 
   // Function to show the dialog where the user has to choose if he want to safe his values as a template
-  Future<void> showTemplateDialog(String emptyField) async {
+  Future<void> showTemplateDialog(List<String> emptyField) async {
     return showDialog(
         context: context,
         barrierDismissible: false,
@@ -224,7 +224,7 @@ class _AddCamMainState extends State<AddCamMain> {
           return AlertDialog(
             title: Text(AppLocalizations.of(context)!.fieldEmpty),
             content: SingleChildScrollView(
-              child: ListBody(children: <Widget>[Text(emptyField)]),
+              child: ListBody(children: <Widget>[Text(emptyField.join("; "))]),
             ),
             actions: <Widget>[
               TextButton(
@@ -326,7 +326,10 @@ class _AddCamMainState extends State<AddCamMain> {
   }
 
   // checks if required fields are not empty. If one is the name will be returned
-  String validateData() {
+  List<String> validateData() {
+
+    List<String> emptyFields = <String>[];
+
     Map<String, TextEditingController> fields = {
       'CID': id,
       'Rudel': rudelC,
@@ -347,14 +350,13 @@ class _AddCamMainState extends State<AddCamMain> {
 
     for (var entry in fields.entries) {
       if (entry.value.text.isEmpty) {
-        empty = true;
-        return entry.key;
-      } else {
-        empty = false;
+        emptyFields.add(entry.key);
       }
     }
 
-    return "";
+    if (emptyFields.isEmpty) empty = true;
+
+    return emptyFields;
   }
 
   // If the user decides to safe his values as a template this function is called to save the values in the database
@@ -718,11 +720,11 @@ class _AddCamMainState extends State<AddCamMain> {
                       currentStep += 1;
                     });
                   } else {
-                    String emptyField = validateData();
+                    List<String> emptyFields = validateData();
                     // ! always fileed out
-                    empty = false;
+                    empty = true;
                     if (empty == true) {
-                      showTemplateDialog(emptyField);
+                      showTemplateDialog(emptyFields);
                       ();
                       return;
                     } else if (empty == false) {