Enhance NewCustomerModal with callback support and toast notifications

- Add `onCustomerCreated` callback to refresh customer list after creation.
- Integrate `showInfoToast` and `showSuccessToast` for validation and creation feedback.
- Prevent closing modal on backdrop click; add explicit cancel button.
- Refactor `addCustomer` to use `callApi` and centralized routes.
- Simplify customer fetching logic in `CustomersPage` with reusable function.

backend/server/src/main/java/dev/rheinsw/server/customer/controller/CustomerController.java

@@ -16,7 +16,6 @@ import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
-import java.util.Collections;
 import java.util.List;
 import java.util.UUID;
 

internal_frontend/app/customers/page.tsx

@@ -35,28 +35,28 @@ export default function CustomersPage() {
     const pageSize = 15;
     const handleError = useErrorHandler();
 
-    useEffect(() => {
+    const loadCustomers = async () => {
         setLoading(true);
-        fetch('/api/customers')
-            .then(async (response) => {
+        try {
+            const response = await fetch('/api/customers');
             if (!response.ok) {
-                    showError("Failed to fetch customers data")
+                showError("Failed to fetch customers data");
                 throw new Error(`Failed to fetch customers: ${response.statusText}`);
             }
-                return response.json();
-            })
-            .then((data) => {
-                showInfoToast("Customers data loaded")
+            const data = await response.json();
+            showInfoToast("Customers data loaded");
             setCustomers(data);
-            })
-            .catch((error) => {
-                showError("Failed to fetch customers data (1)")
+        } catch (error) {
+            showError("Failed to fetch customers data (1)");
             handleError(error);
             setCustomers([]);
-            })
-            .finally(() => {
+        } finally {
             setLoading(false);
-            });
+        }
+    };
+
+    useEffect(() => {
+        loadCustomers();
     }, [handleError]);
 
     const filtered = useMemo(() => {
@@ -114,7 +114,7 @@ export default function CustomersPage() {
                     <CardContent className="space-y-6">
                         <div className="flex flex-col md:flex-row justify-between items-center gap-4">
                             <Input placeholder="Suche" value={search} onChange={(e) => setSearch(e.target.value)}/>
-                            <NewCustomerModal/>
+                            <NewCustomerModal onCustomerCreated={loadCustomers}/>
                         </div>
 
                         {customers.length === 0 && loading ? (

internal_frontend/components/customers/modal/NewCustomerModal.tsx

@@ -14,8 +14,13 @@ import {CreateCustomerDto, NoteDto, PhoneNumberDto} from "@/services/customers/d
 import {addCustomer} from "@/services/customers/usecases/addCustomer";
 import {validateCustomer} from "@/services/customers/usecases/validateCustomer";
 import {useErrorHandler} from "@/components/error-boundary";
+import {showInfoToast, showSuccessToast} from "@/lib/ui/showToast";
 
-export function NewCustomerModal() {
+interface NewCustomerModalProps {
+    onCustomerCreated?: () => void;
+}
+
+export function NewCustomerModal({ onCustomerCreated }: NewCustomerModalProps) {
     const [step, setStep] = useState(1);
     const [open, setOpen] = useState(false);
     const [email, setEmail] = useState("");
@@ -53,6 +58,7 @@ export function NewCustomerModal() {
         try {
             const result = await validateCustomer({email, companyName, street, zip, city});
             setMatches(result);
+            showInfoToast("Datenvalidierung abgeschlossen");
         } catch (err) {
             handleError(err);
         }
@@ -63,7 +69,11 @@ export function NewCustomerModal() {
         try {
             const payload: CreateCustomerDto = {email, name, companyName, street, zip, city, phoneNumbers, notes};
             await addCustomer(payload);
-            location.reload();
+            showSuccessToast("Kunde erfolgreich erstellt");
+            setOpen(false);
+            if (onCustomerCreated) {
+                onCustomerCreated();
+            }
         } catch (err) {
             handleError(err);
         }
@@ -215,14 +225,16 @@ export function NewCustomerModal() {
 
     return (
         <>
-            <Dialog open={open} onOpenChange={setOpen}>
+            <Dialog open={open} onOpenChange={() => {
+                // Prevent closing on backdrop click - modal can only be closed explicitly
+            }}>
                 <DialogTrigger asChild>
                     <Button onClick={() => {
                         setOpen(true);
                         setStep(1);
                     }}>Neue Kunde</Button>
                 </DialogTrigger>
-                <DialogContent className="w-full max-w-5xl max-h-[95vh] overflow-y-auto">
+                <DialogContent className="w-full max-w-5xl max-h-[95vh] overflow-y-auto" showCloseButton={false}>
                     <DialogHeader><DialogTitle>Neuen Kunden anlegen</DialogTitle></DialogHeader>
                     <div className="mb-4">
                         <div className="text-xs font-semibold mb-2">Schritt {step} von 2</div>
@@ -233,9 +245,14 @@ export function NewCustomerModal() {
                     {matches.length > 0 && renderDuplicationCard()}
 
                     <div className="flex justify-between mt-6">
+                        <div className="flex gap-2">
+                            <Button variant="outline" onClick={() => setOpen(false)}>
+                                Abbrechen
+                            </Button>
                             <Button variant="secondary" disabled={step === 1} onClick={() => setStep(step - 1)}>
                                 Zurück
                             </Button>
+                        </div>
                         {step === 1 ? (
                             <Button
                                 onClick={() => setStep(2)}

internal_frontend/services/customers/usecases/addCustomer.ts

@@ -1,6 +1,9 @@
 "use server";
 
 import {CreateCustomerDto} from "@/services/customers/dtos/createCustomer.dto";
+import {customerRoutes} from "@/app/api/customers/customerRoutes";
+import {callApi} from "@/lib/api/callApi";
+import {UUID} from "node:crypto";
 
 export async function addCustomer(params: CreateCustomerDto): Promise<void> {
     const {email, name, companyName, street, zip, city, phoneNumbers, notes} = params;
@@ -16,15 +19,6 @@ export async function addCustomer(params: CreateCustomerDto): Promise<void> {
         notes: notes.map(({text}) => ({text})),
     };
 
-    const response = await fetch('/api/customers', {
-        method: 'POST',
-        headers: {
-            'Content-Type': 'application/json',
-        },
-        body: JSON.stringify(payload)
-    });
-
-    if (!response.ok) {
-        throw new Error(`Failed to create customer: ${response.statusText}`);
-    }
+    const response = await callApi<UUID>(customerRoutes.create, "POST", payload);
+    console.log(response);
 }