Intermediate LevelReact JS & React 19
How does React Suspense work for asynchronous data fetching and fallback UIs?
❓ Interview Prompt: Explain React Suspense, thrown Promises, Suspense boundaries, `<Suspense fallback={...}>`, and integration with data fetching frameworks.
React Suspense allows components to suspend rendering while waiting for asynchronous operations (code splitting chunks or data fetching):
How Suspense Data Fetching Works:
1
A component reads from a Suspense-enabled resource (TanStack Query, Relay, RSC).
2
If data is pending, the resource throws a Promise up the component tree.
3
The nearest '<Suspense fallback={<Spinner />}>' boundary catches the Promise and renders the fallback UI until the Promise resolves!
Code Implementation Example
jsx
import { Suspense } from 'react';
function UserProfilePage() {
return (
<Suspense fallback={<SkeletonProfile />}>
{/* Suspendable component throws Promise until user data resolves */}
<UserProfileDetails />
</Suspense>
);
}💡Wrapping async suspendable components with Suspense fallback boundaries.
🎯 Interview Key Takeaway
Suspense boundaries catch thrown Promises from data resources, displaying fallback loading UIs automatically.
#Suspense#Data Fetching#Async#Intermediate
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