🚀 Introduction
Next.js has quickly become one of the most powerful frameworks for building fast, scalable, and dynamic web applications. It has gained widespread adoption for its ability to deliver exceptional performance and developer experience, making it an ideal choice for everything from small projects to complex enterprise solutions. Next.js empowers developers with key features like dynamic routing, client-server component architecture, route grouping, and protected pages, all designed to streamline workflows and enhance the quality of the final product.
In this article, we’ll explore some of these powerful features, drawing from recent insights gained through a Next.js app router workshop. By leveraging these capabilities, you can significantly improve both the speed, scalability, and maintainability of your web applications.
🏗️ Layout vs Template
When structuring your Next.js application, it’s crucial to understand the distinction between Layouts and Templates, as each serves a specific purpose in ensuring efficient and maintainable UI management.
Layout
A Layout is designed for elements that remain consistent across multiple pages or routes, such as headers, sidebars, or footers. By nature, layouts do not re-render when navigating between routes, making them an excellent choice for persistent UI components.
- Consistency across routes: Layouts are ideal for elements that should remain static across different parts of the application.
- Efficiency: Since Layouts do not re-render on route changes, they help maintain high performance, ensuring that only relevant parts of the page are refreshed.
Layouts play a fundamental role in maintaining a smooth navigation experience, with the ability to retain elements that do not require reloading.
Template
In contrast, a Template is used for dynamic content that must reset whenever the user navigates to a new route. Templates are re-rendered each time a route changes, making them perfect for situations where different pages or sections need to load different content.
- Dynamic UI: Templates allow for content that needs to refresh or reset with each new navigation event.
- Page-Specific: Templates are useful for pages that require unique or changing content based on user interactions or data fetching.
By utilising templates, developers can tailor the user experience to specific route requirements, providing flexibility and dynamic content management.
🤷♂️ When should you use each?
- Layouts should be used for components that are shared across multiple pages (e.g., navigation elements) and do not require reloading.
- Templates are suited for content that needs to reset or change based on route-specific conditions, ensuring that each page can behave independently.
❌ Not found primitive
Next.js offers a robust way to manage missing content using its Not Found primitive. This feature allows developers to define custom 404 pages on a per-segment basis, ensuring that errors are handled gracefully and only affect the relevant part of the app.
- Segment-specific error handling: With this feature, developers can create custom 404 pages for individual routes or sections, isolating errors and preventing them from affecting other parts of the app.
- Global fallback: The root-level “Not Found” page can be used as a fallback when a custom 404 page isn’t defined for a particular route.
This capability significantly enhances the user experience, ensuring that users aren’t confronted with generic error pages while navigating through the app.
🛑 Error boundaries
Another standout feature of Next.js is Error Boundaries, which allow for graceful error handling at runtime. These boundaries help contain errors within specific segments or components, preventing the entire application from crashing.
- Isolated error handling: When an error occurs, it’s confined to the affected segment, allowing other areas of the application to remain operational.
- Graceful recovery: The reset() method enables recovery from errors, providing a seamless experience for users while ensuring that only the problematic segment is impacted.
Error boundaries provide a robust mechanism for error isolation, improving the overall reliability and stability of your app.
📂 Routing group - simplifying structure without affecting URLs
n Next.js 15, Route Grouping allows developers to logically organise their routes without affecting the URL structure. Using parentheses (), you can group related routes together in the file system, creating a cleaner, more maintainable codebase without altering the URLs users access.
- Logical grouping: Route Grouping offers a way to organise pages or components while keeping URLs intuitive and user-friendly.
- Simplified maintenance: This feature streamlines the organisation of complex applications, especially when dealing with a large number of routes.
# Grouping pages without affecting URLs
pages/
(admin)/
dashboard.js
users.js
📂 Routing dynamic - creating flexible, scalable routes
Next.js allows for the creation of dynamic routes, which are essential for building flexible applications that depend on data-driven content. You can define routes with dynamic segments, which capture URL parameters like post IDs, category slugs, or user profiles.
Single dynamic routes: A route like [slug] captures dynamic URL segments for single-page content such as blog posts or user profiles.
Catch-all dynamic routes: Using the [[...slug]] syntax, you can define catch-all routes that capture multiple or optional segments, adding even more flexibility.
Dynamic routes provide a powerful tool for creating scalable, data-driven applications that respond to changing content and user behaviour
Code example for dynamic routing
# Single dynamic route
pages/posts/[slug].js
# Optional catch-all route
pages/posts/[[...slug]].js
💻 Client vs. 🌐 Server components
Next.js gives you the ability to use both Client and Server components, allowing you to optimise your app’s performance while maintaining flexibility in rendering content.
💻 Client components:
Client components are rendered on the client-side after the initial page load. They are perfect for interactive UI elements that require dynamic behaviour, such as forms or chat widgets. Client components can utilise state, effects, and DOM interactions.
- Rendered on the client (browser): Useful for interactive elements.
- State and effects supported: Ideal for dynamic behaviour like form validation.
🌐 Server components:
Server components, on the other hand, are rendered on the server before the HTML is sent to the client. They are best for static content and data fetching, improving performance, SEO, and First Contentful Paint (FCP).
- Rendered on the server: Offloads rendering to the server, improving performance.
- No state or effects: Focuses on static rendering, ideal for data-fetching pages.
Key Benefits
- Server Components improve performance by reducing the client-side rendering load, while Client Components enable dynamic interactions.
- Server components enhance SEO and FCP since the HTML is pre-generated and sent from the server.
- Client components offer rich interactivity by supporting JavaScript state and DOM manipulation.
💻 Client component code example
🌐 Server component code example
🚀 Bonus tip: Protect Routes with “_” Prefix
In Next.js, you can protect certain routes from being accessed directly by prefixing them with an underscore (_). This helps prevent users from accessing specific routes unless they are logged in or authorised.
Example:
# Prefix routes to protect them
pages/_admin/
dashboard.js
settings.js
🌟 Final thoughts
Next.js offers a wide range of powerful features that can optimise your web applications, streamline routing, and enhance performance. From the use of Client vs. Server components to advanced routing techniques like grouping and dynamic paths, Next.js empowers developers to build scalable, fast, and highly interactive applications.
By leveraging these features, you can improve both the developer experience and the user experience. So, whether you’re building a simple blog or an enterprise-grade application, Next.js has the tools to help you push your development to the next level. Keep experimenting and shaping the future of web development with Next.js 🎉!
What’s your favourite new feature in Next.js 15? Let’s discuss! 👇😊
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Next.JS App router tips for developers - Speaker Deck
🌟 Exploring Next.js 15: Key Takeaways from an Amazing Workshop! 🌟 Big thanks to Alice De Mauro from Vercel for hosting an insightful workshop on Next…
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Top comments (1)
Big thanks to Alice De Mauro from Vercel for hosting an insightful workshop on Next.js 15! 🙌✨ We dove into the power of the new App Router 🚀, explored how Server Components can supercharge performance 🖥️⚡, and saw the magic of Error Boundaries 🛑 and the Not Found primitive 🚧. From grouping routes with () for cleaner paths 📂➡️, to combining Client Components for dynamic interactivity 🖱️ and Server Components for secure, performant rendering 🎯, it was packed with actionable tips to build scalable, lightning-fast apps. 🌐💡 I’m looking forward to leveraging these insights to architect even more scalable and efficient applications! 💻🔥