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Taming the Logout Jank: Handling State Resets in React Native

#react #react-native #javascript #async

TL;DR

  • UseEffect Timing: Utilize useEffect judiciously to handle asynchronous state updates, including logout state management.
  • Promises over Timeouts: Avoid using arbitrary timeouts; instead employ microtask queue preferences with promises.
  • State Reset Strategy: Avoid premature UI state resets by ensuring they align with successful logout completion.
  • Banish the Jank: Carefully control when UI state changes to minimize visual disruptions.
  • The Onboarding Gates: Make sure onboarding transitions align with authentication state changes.

Today, I’m diving into a bug that messes with user experience on logout in our React Native app. The core issue is ensuring the user reset happens post-onboarding screen transition. The initial approach feels hacky, involving a promise resolution after a one-second timeout. It’s ugly and feels wrong.

Initial Attempts and Insights

Using useEffect in my AppDataContext was my opening move. It watches the wasLogoutSuccessful state, but the promise-timeout combo doesn’t sit well—it’s the kind of duct-tape fix that merely masks deeper problems.

The microtask queue route feels appealing, where leveraging a promise should ensure it runs after ongoing operations, rather than relying on setImmediate or setTimeout. The initial execution flow needs to wait for UI completion due to ongoing renderings—timing, indeed, becomes critical.

Problem Solving Steps

  1. Observe and Identify: Logging out prompts an OS-level alert, causing the app to go into the background, confusingly triggering substantive state reset mechanisms.

  2. State Management Re-evaluation: Instead of relying on a timer, I opted for wasLogoutSuccessful as a cue to reset vision and palette states when absolutely necessary.

  3. Effect Cleanup: Introduced a variable to store the timeout ID. Implemented a cleanup within useEffect to clear dangling timeouts, assuaging the cleanup anxiety.

  4. Guards on Logout State: Revisited the useVision and themeContext files to replace potentially erroneous states with wasLogoutSuccessful.

  5. Empirical Testing: By running tests on iOS and comparing visual effects (or lack thereof) on logout transitions, the app seems to behave just right - jank free.

Broader Observations

Emphasizing the importance of waiting for transitions to complete avoids jarring UI resets. Curiously, rather than setting integral state values to undefined or allowing state resets, maintaining a coherent palette structure mitigates user experience disruptions upon logout.

Moreover, this exploration underscores an oft-overlooked aspect: Acceptable jank might be tolerable when fleeting (sub-300ms) and post-logout, though aiming for fluidity is paramount. It’s about acceptable thresholds, providing insights into where performance can concede for overall stability, especially during logout—a critical navigation transition.

In essence, the goal was balance—ensuring logout mechanics reflect only on wasLogoutSuccessful, minimizing UI jolts, and ultimately presenting users a seamless transition experience.