In this guide, we'll explore how to create a like button for an MDX-based Next.js application. The button will cater to both authenticated and anonymous users by leveraging local storage for temporary data storage and a PostgreSQL database hosted on Vercel for persistent storage. This ensures a seamless user experience with consistent data retention across devices and sessions.

Check out a live example of the implementation, and find the complete code for this project on GitHub.

Context

This implementation uses Next.js 14, which introduces Server Actions, enabling efficient server-side operations directly from React components. This eliminates the need for API routes, streamlining client-server interactions.

The project integrates the @next/mdx package for combining Markdown and React components. This approach is particularly useful for content-driven sites requiring dynamic interactivity.

By combining local storage and a PostgreSQL database, the like button offers robust functionality. Anonymous users have their likes tracked in local storage, while authenticated users' likes are stored persistently in the database.

Prerequisites

Before starting, ensure you have the following:

• A Next.js project set up
• Vercel PostgreSQL database credentials
• Installed npm packages: react-icons, uuid, and @vercel/postgres

Key Steps

1. Set Up Environment Variables
   Configure a .env.local file in the root of your project with your Vercel PostgreSQL credentials.

2. Create the Like Button Component
   Develop a LikeButton React component to manage the like button's functionality, including state management, local storage for anonymous users, and database interaction for persistent storage.

3. Implement Server Actions
   Use Next.js Server Actions for database operations, such as counting likes, adding likes, removing likes, and verifying whether a user has liked a specific post.

4. Integrate the Like Button in MDX Content
   Embed the LikeButton component directly within your MDX content. MDX allows the seamless inclusion of React components alongside Markdown, enhancing interactivity in content-driven applications.

Benefits of the Approach

• Dynamic Functionality: The combination of React components and MDX provides a flexible platform for building dynamic, content-rich applications.
• Persistent Storage: By using local storage for anonymous users and PostgreSQL for authenticated ones, the solution caters to a diverse audience while ensuring data consistency.
• Efficient Server Operations: Server Actions in Next.js simplify client-server communication, reducing overhead and improving performance.

Additional Resources

For more information, visit the official Vercel documentation on PostgreSQL database integration.