Next.js: Dynamic Routing with API Integration.

Next.js provides a file-based routing system that supports dynamic routes (e.g., /product/[id]). You can combine this with dynamic data fetching to create flexible and scalable applications. This is particularly useful for cases like e-commerce product pages, user profiles, or any content with unique identifiers.

Example: Dynamic Product Pages

1. Set Up the Dynamic Route

Create a file named [id].tsx inside a folder like /pages/product/:

pages/product/[id].tsx

2. Fetch Data for the Dynamic Route

// pages/product/[id].tsx

import { GetStaticPaths, GetStaticProps } from 'next';

type ProductProps = {
  product: {
    id: string;
    name: string;
    description: string;
    price: number;
  };
};

export default function ProductPage({ product }: ProductProps) {
  return (
    <div>
      <h1>{product.name}</h1>
      <p>{product.description}</p>
      <p>Price: ${product.price}</p>
    </div>
  );
}

// Generate dynamic paths for the product pages
export const getStaticPaths: GetStaticPaths = async () => {
  const res = await fetch('https://api.example.com/products');
  const products = await res.json();

  // Map over the products to define paths
  const paths = products.map((product: { id: string }) => ({
    params: { id: product.id },
  }));

  return {
    paths, // Pre-render these paths at build time
    fallback: 'blocking', // Dynamically render other pages on request
  };
};

// Fetch product data for each page
export const getStaticProps: GetStaticProps = async ({ params }) => {
  const res = await fetch(`https://api.example.com/products/${params?.id}`);
  const product = await res.json();

  // Pass the product data as props
  return {
    props: { product },
    revalidate: 10, // Revalidate every 10 seconds
  };
};

3. Handle Non-existent Pages

To handle cases where the id doesn’t exist, return a notFound property in getStaticProps:

export const getStaticProps: GetStaticProps = async ({ params }) => {
  const res = await fetch(`https://api.example.com/products/${params?.id}`);
  
  if (res.status === 404) {
    return { notFound: true };
  }

  const product = await res.json();

  return {
    props: { product },
    revalidate: 10,
  };
};

Key Features of This Approach:

1. SEO-Friendly: Pages are pre-rendered with full HTML, making them great for search engines.

2. Scalable: You can use fallback rendering (fallback: 'blocking') to dynamically generate pages for new data.

3. Real-Time Updates: Combine with revalidate to ensure the data stays fresh without manual deployments.

4. Error Handling: Handle 404s or other errors gracefully with notFound.

This method allows you to build highly dynamic and responsive web applications that scale easily!