In this lesson, we explore the world of Optimistic UI, an approach that's changing the way we interact with web apps. Optimistic UI is about making actions in web apps feel instant, providing immediate feedback before the server even responds. We'll walk through how this approach can make web apps more responsive and user-friendly. We will delve into the implementation details that enable this near-instantaneous user experience. By preemptively assuming that user actions will be successful, Optimistic UI updates the app's interface immediately rather than waiting for server confirmation. This strategy enhances the perception of speed, keeps users engaged, and reduces frustration caused by waiting.
However, implementing Optimistic UI isn't without its challenges. We will discuss the importance of handling the scenarios where the server eventually returns an error and how to gracefully revert changes in the user interface. This requires careful planning and robust error-handling strategies to maintain a consistent and trustworthy user experience.
Additionally, we'll examine the situations where Optimistic UI is most effective and where it might not be the best fit. Understanding these nuances is crucial for developers and designers alike, as it helps in making informed decisions about where to apply this approach for maximum impact.
For a practical illustration, consider Twitter's implementation of Optimistic UI. When a user likes a tweet, the like button immediately changes colour and the like count increments, even before the server has processed the request. We can verify this by throttling our network speed from browser dev tools, and we will see that the button shows instant feedback, even while the POST request to like the tweet is pending. This gives the user instant feedback, creating a seamless and satisfying experience.
However, if the server fails to process the like, Twitter has mechanisms in place to revert the UI to its previous state. The like count decreases, and the button's colour changes back. This demonstrates the necessity of having robust error handling when implementing Optimistic UI.
