Prevent invoicing multiple tasks for different clients

lib/redux/project/project_actions.dart

@@ -18,6 +18,7 @@ import 'package:invoiceninja_flutter/redux/document/document_actions.dart';
 import 'package:invoiceninja_flutter/redux/project/project_selectors.dart';
 import 'package:invoiceninja_flutter/ui/app/entities/entity_actions_dialog.dart';
 import 'package:invoiceninja_flutter/utils/completers.dart';
+import 'package:invoiceninja_flutter/utils/dialogs.dart';
 import 'package:invoiceninja_flutter/utils/localization.dart';
 
 class ViewProjectList implements PersistUI {
@@ -272,6 +273,23 @@ void handleProjectAction(
             ..clientId = project.clientId));
       break;
     case EntityAction.invoiceProject:
+      String lastClientId = '';
+      bool hasMultipleClients = false;
+      projects.forEach((project) {
+        final clientId = (project as ProjectEntity).clientId ?? '';
+        if (clientId.isNotEmpty) {
+          if (lastClientId.isNotEmpty && lastClientId != clientId) {
+            hasMultipleClients = true;
+          }
+          lastClientId = clientId;
+        }
+      });
+      if (hasMultipleClients) {
+        showErrorDialog(
+            context: context, message: localization.multipleClientError);
+        return;
+      }
+
       final items = <InvoiceItemEntity>[];
       projects.forEach((project) {
         items.addAll(

lib/redux/task/task_actions.dart

@@ -383,6 +383,23 @@ void handleTaskAction(
       break;
     case EntityAction.invoiceTask:
     case EntityAction.addToInvoice:
+      String lastClientId = '';
+      bool hasMultipleClients = false;
+      tasks.forEach((task) {
+        final clientId = (task as TaskEntity).clientId ?? '';
+        if (clientId.isNotEmpty) {
+          if (lastClientId.isNotEmpty && lastClientId != clientId) {
+            hasMultipleClients = true;
+          }
+          lastClientId = clientId;
+        }
+      });
+      if (hasMultipleClients) {
+        showErrorDialog(
+            context: context, message: localization.multipleClientError);
+        return;
+      }
+
       tasks.sort((taskA, taskB) {
         final taskAEntity = taskA as TaskEntity;
         final taskBEntity = taskB as TaskEntity;

lib/utils/i18n.dart

@@ -16,6 +16,7 @@ mixin LocalizationsProvider on LocaleCodeAware {
   static final Map<String, Map<String, String>> _localizedValues = {
     'en': {
       // STARTER: lang key - do not remove comment
+      'multiple_client_error': 'Error: records belong to more than one client',
       'register_label': 'Create your account in seconds',
       'login_label': 'Login to an existing account',
       'add_to_invoice': 'Add To Invoice',
@@ -69669,6 +69670,11 @@ mixin LocalizationsProvider on LocaleCodeAware {
       _localizedValues[localeCode]['login_label'] ??
       _localizedValues[localeCode]['login_label'];
 
+
+  String get multipleClientError =>
+      _localizedValues[localeCode]['multiple_client_error'] ??
+      _localizedValues[localeCode]['multiple_client_error'];
+
   // STARTER: lang field - do not remove comment
 
   String lookup(String key) {