#react 18

This Talk introduces server components in React, which provide an intermediate format for rendering and offer advantages for both client-side and server-side rendering. Server components reduce bundle size on the client and improve search engine optimization. They abstract the rendering process, allowing for faster rendering and flexibility in choosing where to render components. While server components are still in the experimental stage, Next.js is a good starting point to try them out.

React 18's concurrent rendering, specifically the useTransition hook, optimizes app performance by allowing non-urgent updates to be processed without freezing the UI. However, there are drawbacks such as longer processing time for non-urgent updates and increased CPU usage. The useTransition hook works similarly to throttling or bouncing, making it useful for addressing performance issues caused by multiple small components. Libraries like React Query may require the use of alternative APIs to handle urgent and non-urgent updates effectively.

The Talk discussed Concurrent React and its impact on app performance, particularly in relation to long tasks on the main thread. It explored parallelism with workers and the challenges of WebAssembly for UI tasks. The concepts of concurrency, scheduling, and rendering were covered, along with techniques for optimizing performance and tackling wasted renders. The Talk also highlighted the benefits of hydration improvements and the new profiler in Concurrent React, and mentioned future enhancements such as React fetch and native scheduling primitives. The importance of understanding React internals and correlating performance metrics with business metrics was emphasized.

This Talk explores React's internal jargon, specifically fiber, which is an internal unit of work for rendering and committing. Fibers facilitate efficient updates to elements and play a crucial role in the reconciliation process. The work loop, complete work, and commit phase are essential steps in the rendering process. Understanding React's internals can help with optimizing code and pull request reviews. React 18 introduces the work loop sync and async functions for concurrent features and prioritization. Fiber brings benefits like async rendering and the ability to discard work-in-progress trees, improving user experience.

This Talk explores the internals of React Fiber and its implications. It covers topics such as fibres and units of work, inspecting elements and parent matching, pattern matching and coroutines, and the influence of coroutines on concurrent React. The Talk also discusses effect handlers in React, handling side effects in components, and the history of effect handlers in React. It concludes by emphasizing the importance of understanding React internals and provides learning resources for further exploration.

Sudhanshu Yadav discusses the incremental concurrent feature in React 18 and the need for concurrent mode to provide a better user experience. Time slicing is the key pattern enabling concurrent features. Background rendering and unit of work are used to achieve asynchronous rendering and eventual consistency. Concurrent mode introduces a new pattern called differing for immediate rendering and adjusting based on available resources. React provides APIs for deferred updates and transitions. Implementing concurrent mode APIs can be complex, but it offers benefits like avoiding update starvation and reusing work. Scheduling and slots are used to control execution and dynamic FPS control. Handling multiple transitions can be challenging, but the React 18 working group discussions provide insights into the team's efforts to improve the user experience.

The Talk discusses the future of React and introduces new APIs, including streaming rendering and server components. React Suspense allows for asynchronous loading of components and data fetching. The use of serverless computing, specifically Cloudflare Workers, is explored as a way to improve performance. The Talk emphasizes the potential for simplifying the React ecosystem and the excitement about the new API.

I'm going to be speaking about concurrency within React and how you can use it to improve performance within your applications. Concurrency is crucial for optimizing responsiveness and ensuring a good user experience in complex applications. React breaks up the rendering process into render and commit phases, allowing interruption of the render phase for prioritizing user interactions. React's task scheduler handles tasks in small chunks, ensuring a fluid user experience and responsiveness. High-priority tasks include user interactions, while lower priority tasks involve fetching data or rendering long lists. React introduced new hooks, useTransition and useDeferredValue, for handling state update priorities. The deferred value hook allows for deferring the updates of non-critical UI values, while Suspense for Data Fetching improves the performance of data fetching in React applications. Concurrency is useful for handling real-time search inputs, seamless tab or component switching, rendering large lists, and animating transitions. However, there are drawbacks to concurrency, such as potential delays in non-urgent updates and limited benefits for expensive components. Concurrency may add CPU strain and requires an understanding of React's background behavior for effective debugging. Use suspense on parent level components for data fetching. Performance profiling can help test the effectiveness of transition hooks.

Today's Talk introduces concurrent React and highlights the importance of fast and slow updates in user interfaces. It explains how concurrent rendering improves UI performance by allowing fast updates to proceed without being blocked by slow updates. The concept of assigning priorities to renders is discussed, with high priority renders being synchronous and low priority renders being interruptible. The Talk also mentions the benefits of using concurrent features in navigation and list filtering. Overall, concurrent React enhances rendering with interruptibility and prioritization, making the application feel faster and more responsive.

This Talk discusses using suspense and GraphQL with Apollo client to build great end user experiences. It explains the core concepts of React suspense and how to fetch data in suspense with Apollo client's new suspense hooks. The Talk also covers optimizing the loading experience by adding suspense boundaries, using the defer directive in GraphQL, and integrating suspense hooks with React 18 transitions. Future plans include new APIs like suspenseful use fragment and lazy use background query in Apollo client 3.9. Testing strategies for suspense in components and customizing loading states are also mentioned.

The talk discusses the ramifications of the new concurrent features in React and the misconceptions around the rendering model. It explores the changes in the rendering process and the need to handle state carefully. The talk also highlights the challenges in managing communication with the outside world and the recommended libraries for synchronization. It mentions the benefits of using concurrent mode in existing frameworks and the difficulties in building demos and enforcing immutability. Finally, it emphasizes the benefits of concurrent mode for heavy components.

React Server Components is a recent feature introduced with the React team and launched with Next.js 12. They allow for rendering components on the server, improving performance and data fetching. Server components can be used alongside client-side rendering and provide direct access to server resources. However, they are still in the experimental stage and have some limitations, such as not being able to use hooks or event handlers. Challenges include importing server components in client components and making third-party API calls.

This talk explores the implications of the new concurrent features in React 18 and how they impact developers. It discusses the core premise of React and the importance of pure function components. The talk also addresses misconceptions about React's rendering process and the prevention of tearing in applications. Additionally, it highlights the reconciliation and commit phases in React and the challenges of dependency management in state management libraries.

Today's Talk introduces React Snots, a new way of composition for design systems. The configuration way provides flexibility but can lead to uncontrolled use cases and wrong patterns. React Slots RFC was created to address the limitations of React's support for web components and slots. It introduces createHost and createSlot APIs to enable component composition and solve previous problems. React Slots RFC allows for flexible component styling and the creation of complex structures without rendering them to the browser.

This Talk explores the concept of subtle loading in software development, focusing on techniques to provide a fast and seamless user experience. Tips include avoiding waterfall loading, optimizing loading sequences, and handling loading scenarios for users on faster connections. The use of React 18 APIs, such as start transition, is recommended to achieve an optimistic loading experience. Overall, the Talk emphasizes the importance of improving user experience through subtle loading techniques.

This Talk discusses React performance and how re-renders can affect it. It highlights common mistakes and misconceptions, such as the overuse of useMemo and useCallback hooks. The importance of React.memo in preventing unnecessary child component re-renders is emphasized. Creating components in render functions is identified as a major performance killer, and the benefits of moving state down and wrapping state around children are explained. The Talk also covers optimizing component rendering through memoization and provides a recap of the key points.