How can I prevent the "Page not found" error when implementing dynamic

I am sharing a tentative flowchart for dynamic routing with Static Site Generation (SSG), please check and let me know if this works for you?

Another approach is :

• Validate getStaticProps:

  • Check getStaticProps fetches the correct data for each slug:

    export async function getStaticProps({ params }) {
        const data = await fetchDataForSlug(params.slug); // Replace with your data fetching logic
        if (!data) {
            return { notFound: true }; // Return a 404 if the slug data doesn't exist
        }
        return { props: { data } };
    }
    

• 404 Pages for Missing Data:

  • If fetchDataForSlug doesn't return data for certain slugs, ensure notFound: true is handled in getStaticProps.

• Verify CMS/API Integration:

  • Ensure the CMS or API provides consistent and accurate data for all expected slugs.

• Local Testing:

  • Test your application locally using npm run build && npm start to verify that the static pages are being generated.

• Structure of getStaticPaths:

  • Check getStaticPaths is returning the paths correctly. 
  • Double-check the params object matches the dynamic route's file name ([slug].js).

export async function getStaticPaths() {
    const slugs = await fetchSlugs(); // Replace with your CMS/API logic
    const paths = slugs.map((slug) => ({ params: { slug } }));
    return { paths, fallback: false }; // Or 'blocking' for fallback rendering
}

• Verify Slugs:

  • Log the slugs and paths in getStaticPaths to ensure all required slugs are fetched and mapped correctly.

• Check Fallback Setting:

  • If fallback is false, any slug not listed in paths will show a 404 error. Use fallback: true or blocking to handle pages dynamically.

• Build Logs:

  • During the build process, ensure that all expected pages are generated. Look for skipped or missing paths.

export async function getStaticPaths() {
  const slugs = await fetchSlugs(); 

  return {
    paths: slugs.map((slug) => ({ params: { slug } })), 
    fallback: false, 
  };
}

Your getStaticPaths  should look like above and the getStaticProps correctly fetches data for each slug :

export async function getStaticProps({ params }) {
  const slug = params.slug; 
  const data = await fetchDataForSlug(slug); 

  if (!data) {
    return { notFound: true }; 
  }

  return {
    props: { data },
  };
}