fix: Prevent double submission in Create Page dialog

- Add ref-based double submission protection (isSubmittingRef)
- Extract handleSubmit function with isPending checks
- Add loading spinner during submission
- Disable inputs during submission
- Suppress error toast for duplicate prevention errors

admin-spa/src/routes/Appearance/Pages/components/CreatePageModal.tsx

@@ -1,4 +1,4 @@
-import React, { useState, useEffect } from 'react';
+import React, { useState, useEffect, useRef } from 'react';
 import { useMutation } from '@tanstack/react-query';
 import { api } from '@/lib/api';
 import { __ } from '@/lib/i18n';
@@ -15,7 +15,7 @@ import {
     DialogTitle,
 } from '@/components/ui/dialog';
 import { toast } from 'sonner';
-import { FileText, Layout } from 'lucide-react';
+import { FileText, Layout, Loader2 } from 'lucide-react';
 
 interface PageItem {
     id?: number;
@@ -36,18 +36,30 @@ export function CreatePageModal({ open, onOpenChange, onCreated }: CreatePageMod
     const [title, setTitle] = useState('');
     const [slug, setSlug] = useState('');
 
+    // Prevent double submission
+    const isSubmittingRef = useRef(false);
+
     // Get site URL from WordPress config
     const siteUrl = window.WNW_CONFIG?.siteUrl?.replace(/\/$/, '') || window.location.origin;
 
     // Create page mutation
     const createMutation = useMutation({
-        mutationFn: async () => {
-            if (pageType === 'page') {
-                const response = await api.post('/pages', { title, slug });
-                return response.data;
+        mutationFn: async (data: { title: string; slug: string }) => {
+            // Guard against double submission
+            if (isSubmittingRef.current) {
+                throw new Error('Request already in progress');
+            }
+            isSubmittingRef.current = true;
+
+            try {
+                const response = await api.post('/pages', { title: data.title, slug: data.slug });
+                return response.data;
+            } finally {
+                // Reset after a delay to prevent race conditions
+                setTimeout(() => {
+                    isSubmittingRef.current = false;
+                }, 500);
             }
-            // For templates, we don't create them - they're auto-created for each CPT
-            return null;
         },
         onSuccess: (data) => {
             if (data?.page) {
@@ -64,6 +76,10 @@ export function CreatePageModal({ open, onOpenChange, onCreated }: CreatePageMod
             }
         },
         onError: (error: any) => {
+            // Don't show error for duplicate prevention
+            if (error?.message === 'Request already in progress') {
+                return;
+            }
             // Extract error message from the response
             const message = error?.response?.data?.message ||
                 error?.message ||
@@ -82,15 +98,28 @@ export function CreatePageModal({ open, onOpenChange, onCreated }: CreatePageMod
         }
     };
 
+    // Handle form submission
+    const handleSubmit = () => {
+        if (createMutation.isPending || isSubmittingRef.current) {
+            return;
+        }
+        if (pageType === 'page' && title && slug) {
+            createMutation.mutate({ title, slug });
+        }
+    };
+
     // Reset form when modal closes
     useEffect(() => {
         if (!open) {
             setTitle('');
             setSlug('');
             setPageType('page');
+            isSubmittingRef.current = false;
         }
     }, [open]);
 
+    const isDisabled = pageType === 'page' && (!title || !slug) || createMutation.isPending || isSubmittingRef.current;
+
     return (
         <Dialog open={open} onOpenChange={onOpenChange}>
             <DialogContent className="sm:max-w-[500px]">
@@ -141,6 +170,7 @@ export function CreatePageModal({ open, onOpenChange, onCreated }: CreatePageMod
                                     value={title}
                                     onChange={(e) => handleTitleChange(e.target.value)}
                                     placeholder={__('e.g., About Us')}
+                                    disabled={createMutation.isPending}
                                 />
                             </div>
 
@@ -151,6 +181,7 @@ export function CreatePageModal({ open, onOpenChange, onCreated }: CreatePageMod
                                     value={slug}
                                     onChange={(e) => setSlug(e.target.value.toLowerCase().replace(/[^a-z0-9-]/g, ''))}
                                     placeholder={__('e.g., about-us')}
+                                    disabled={createMutation.isPending}
                                 />
                                 <p className="text-xs text-muted-foreground">
                                     {__('URL will be: ')}<span className="font-mono text-primary">{siteUrl}/{slug || 'page-slug'}</span>
@@ -161,14 +192,21 @@ export function CreatePageModal({ open, onOpenChange, onCreated }: CreatePageMod
                 </div>
 
                 <DialogFooter>
-                    <Button variant="outline" onClick={() => onOpenChange(false)}>
+                    <Button variant="outline" onClick={() => onOpenChange(false)} disabled={createMutation.isPending}>
                         {__('Cancel')}
                     </Button>
                     <Button
-                        onClick={() => createMutation.mutate()}
-                        disabled={pageType === 'page' && (!title || !slug) || createMutation.isPending}
+                        onClick={handleSubmit}
+                        disabled={isDisabled}
                     >
-                        {createMutation.isPending ? __('Creating...') : __('Create Page')}
+                        {createMutation.isPending ? (
+                            <>
+                                <Loader2 className="w-4 h-4 mr-2 animate-spin" />
+                                {__('Creating...')}
+                            </>
+                        ) : (
+                            __('Create Page')
+                        )}
                     </Button>
                 </DialogFooter>
             </DialogContent>