Static-to-Dynamic Error

[Saeedinum]

Removed generateStaticParams in /products/[id]/page.tsx Due to Static-to-Dynamic Error

Overview

The /products/[id] page encountered errors due to a conflict between static generation and dynamic cookie access. I removed generateStaticParams to make the page dynamic (SSR), resolving the issue. This documents the problem, the fix, and a future solution to restore static generation.

Problem Description

The /products/[id] page used generateStaticParams to pre-render pages at build time, but fetchUser (calling getUser) accessed cookies, which isn’t possible during static generation. Additionally, Supabase’s createClient tried to modify cookies during rendering, which is only allowed in Server Actions or Route Handlers.

Errors Encountered

1. Static-to-Dynamic Error:

   Error: Page changed from static to dynamic at runtime /products/9b601a62-d80e-4f8c-83e3-82c3b41e2334, reason: cookies
   

   • Caused by accessing cookies during runtime on a statically generated page.

2. Cookies Modification Error:

   Error: Cookies can only be modified in a Server Action or Route Handler.
   

   • Supabase’s createClient attempted to set cookies during Server Component rendering.

Affected Code

• Original generateStaticParams (removed):

  export async function generateStaticParams() {
    const data = await getAllProducts().then((res) => res.data).catch(() => []);
    return data.length ? data.slice(0, 5).map((product) => ({ id: product.id })) : [];
  }

• Problematic Code in ProductDetailsPage:

  const data = await fetchUser(); // Accesses cookies via getUser
  const productResponse = (data?.data?.id && (await fetchProductDetails(id, data.data.id))) || (await fetchProductDetails(id));

Resolution

I removed generateStaticParams, making the page dynamic (SSR). This allows fetchUser to access cookies at request time. I also added ISR to cache the page:

export const revalidate = 3600; // Revalidate every hour

Implications:

• Performance: SSR is slower than static generation, but ISR helps.
• SEO: Still SEO-friendly, but static pages are faster for crawlers.
• Scalability: Increased server load; monitor in production.

Suggested Future Solution

To restore static generation:

1. Remove fetchUser from ProductDetailsPage to avoid cookie access during rendering.
2. Fetch user data client-side in ProductsClient using createBrowserClient from @supabase/ssr.
3. Reintroduce generateStaticParams to pre-render product pages.

Example:

• Static ProductDetailsPage:

  export default async function ProductDetailsPage({ params }: { params: Promise<{ id: string }> }) {
    const { id } = await params;
    const productResponse = await fetchProductDetails(id); // No userId
    if (!productResponse.success || !productResponse.data) notFound();
    const { product, category, isInCart, isInWishlist } = productResponse.data;
    return <ProductsClient product={product} category={category} isInCart={isInCart} isInWishlist={isInWishlist} userId={null} />;
  }

• Client-Side User Fetch in ProductsClient:

  useEffect(() => {
    const fetchUserData = async () => {
      const supabase = createBrowserClient(process.env.NEXT_PUBLIC_SUPABASE_URL!, process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!);
      const { data: { user } } = await supabase.auth.getUser();
      if (user) setUserId(user.id); // Fetch isInCart, isInWishlist similarly
    };
    fetchUserData();
  }, []);

Next Steps

• Monitor performance in production to ensure SSR with ISR is sustainable.
• Consider implementing the static generation solution for better SEO and performance.
• Investigate cookies modification issue if it reappears (check Supabase auth setup).

Additional Notes

• Context: Rezogifts (e-commerce for gaming gift cards) using Next.js App Router and Supabase.
• Priority: Medium (current fix works, but static generation is preferred for SEO).