Async Boundary

Problem

Components flash between loading states inconsistently, showing jarring skeleton screens or leaving parts of the UI frozen while data loads. Without centralized loading boundaries, every component must manage its own loading state, creating a chaotic user experience with spinners appearing and disappearing randomly across the page.

Solution

Wrap async components in boundaries that declare what to show while loading, centralizing loading states at logical UI sections. This creates predictable loading patterns where entire regions transition together rather than individual components flickering independently.

Example

This example shows how to use React Suspense to define a loading boundary that displays a spinner while an async component loads its data.

// Wrap async components in Suspense to manage loading state
<Suspense fallback={<Spinner />}>
  {/* This component can load data asynchronously */}
  {/* The Spinner will show until the component is ready */}
  <UserProfile userId={userId} />
</Suspense>

Benefits

• Creates predictable, cohesive loading patterns across UI regions.
• Reduces visual chaos by preventing individual components from flickering.
• Centralizes loading logic instead of scattering it across components.
• Improves perceived performance by showing meaningful loading states.
• Simplifies component code by moving loading concerns to boundaries.

Tradeoffs

• Requires framework support like React Suspense or similar patterns.
• Can delay showing any content until all data within boundary loads.
• May need careful boundary placement to balance granularity and cohesion.
• Debugging loading issues becomes harder with multiple nested boundaries.
• Not all components or data fetching patterns work well with boundaries.