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Skillintermediate
bundle conditional
Load large data or modules only when a feature is activated.
Claude Code Knowledge Pack7/10/2026
Overview
Conditional Module Loading
Load large data or modules only when a feature is activated.
Example (lazy-load animation frames):
function AnimationPlayer({ enabled, setEnabled }: { enabled: boolean; setEnabled: React.Dispatch<React.SetStateAction<boolean>> }) {
const [frames, setFrames] = useState<Frame[] | null>(null)
useEffect(() => {
if (enabled && !frames && typeof window !== 'undefined') {
import('./animation-frames.js')
.then(mod => setFrames(mod.frames))
.catch(() => setEnabled(false))
}
}, [enabled, frames, setEnabled])
if (!frames) return
return
}
The typeof window !== 'undefined' check prevents bundling this module for SSR, optimizing server bundle size and build speed.