Tim Neutkens discusses the Next.js app router, leveraging Server Components and React's cache API. He explains partial revalidation and UI updates from server-side state changes, as well as caching layers and stability focus. Also discussed are server component rendering, composition vs. top-down data flow, revalidation after a user event, back and forward navigation, and current focus on stability, performance, education, and TurboPack.
The Next.js app router leverages Server Components and React's new cache API to bring composability to server-side code.
Server Actions enable partial revalidation in a single round trip to the server, allowing for targeted refreshes and optimal code structure.
Caching mechanisms in React Server Components and App Router applications improve performance and optimize rendering and composition strategies.
Backward and forward navigation in Next.js is handled through caching and rendering of previous pages, ensuring instant rendering and a smooth user experience.
Deep dives
Benefits of React Cache
React Cache provides memoization capabilities, allowing functions to return the same value when called with the same arguments within the same request. This improves performance and ensures consistent data across components. It is similar to memoization in other languages where expensive operations are only performed once and then cached for subsequent calls. In the context of React, the cache API encourages co-location of data requirements with components, simplifying development and enabling more composable and deleteable code.
Composition and Co-locating Data Dependencies
React Server Components (RSC) and the App Router architecture promote composition and co-location of data dependencies within components. This enables partial rendering and selective re-rendering based on specific component requirements, rather than relying on top-down data flow. It encourages optimal code structure, facilitates maintenance, and allows components to be easily added or removed without impacting other parts of the application. The architecture aligns with the principles of React Query and SWR, as it supports granular data fetching and component-based data management without the need for global context or complex data propagation.
Caching and Optimizations
Caching plays a crucial role in optimizing React Server Components and App Router applications. The React cache API is used for memoization within a single request, reducing duplicate work and ensuring consistent values for specific function calls. The Nexus data cache provides caching across requests, improving performance by utilizing cached data instead of making unnecessary database or API calls. These caching mechanisms enable efficient rendering, composition, and optimization strategies, enhancing the overall performance and user experience of the application.
Refreshing Data and Component Rendering
When it comes to refreshing data and rendering components, An App Router application provides various options. Actions performed within the browser, such as navigation or form submission, can trigger re-rendering of specific components based on updated data. The cache API and other methods, like server actions or tag-based updates, allow for targeted refreshes and ensure components reflect the latest data. The architecture promotes granular updates and prevents unnecessary re-renders while maintaining consistency and improving performance.
Navigating and refreshing pages
Navigating and refreshing pages in Next.js using server components and SWR involves calling mutate on the SWR store and using server actions. Server actions are used for most types of mutations and rely on the 'refellidate pod' and 'refellidate tag' functions to rerender the page and invalidate the router cache. These functions allow developers to update the database, render the new page, and handle caching efficiently in a single round trip to the server.
Caching and revalidation
Next.js provides various caching layers, such as the data cache and full route cache, that help optimize server rendering and data fetching. The data cache facilitates quick data reads, while the full route cache stores fully rendered HTML and RC payload. You can use functions like 'refellidate pod' and 'refellidate tag' to manually invalidate cache entries and ensure that pages render with the latest data. By understanding the caching layers and using proper cache invalidation strategies, developers can enhance the performance and efficiency of their Next.js applications.
Backward and forward navigation
Next.js handles backward and forward navigation by caching and rendering the previous pages. This ensures instant rendering and proper scroll positions, providing a smooth user experience. Developers can control cache invalidation by using functions like 'refellidate pod' and 'refellidate tag' to purge and update specific cache entries. The caching behavior for back and forward navigation can be customized and adjusted to suit different requirements. Additionally, developers can create custom components using 'refellidate pod' and 'useEffect' to handle routing and cache updates effectively.
Tim joins Sam to talk about his work on the new app router in Next.js 13. He explains how the app router leverages Server Components and React’s new cache API to bring a new level of composability to server-side code, how Server Actions are being designed to enable partial revalidation in a single round trip to the server, and how to think about UI updates as a result of server-side state changes.
Topics include:
0:00 - Intro
2:53 - Rendering Server Components and the RSC payload
21:49 - Composition vs. top-down data flow and the React cache
53:35 - Revalidation after a user event and Server Actions
1:06:37 - Revalidation after a server-side state change
1:14:02 - Back and forward navigation
1:21:43 - Caching layers
1:30:53 - Current focus on stability, performance, education, and TurboPack
