Files
archy/packages/app/src/composables/useLazyImage.ts
T
DorianandClaude Opus 4.6 1664fbbb6f feat(perf): performance composables for lazy loading, dedup, prefetch, cleanup (M18.1-M18.8)
- Image lazy loading: IntersectionObserver + blur-up placeholder
- Request deduplication: in-flight Promise sharing by URL+body key
- Prefetch on hover: 5-minute cache for pre-fetched detail data
- Memory leak audit: useCleanup() tracks intervals/listeners/observers
- Background sync queue: retry failed IDB saves on visibility change
- Bundle splitting: composable architecture enables tree-shaking

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-04 00:59:03 +00:00

41 lines
1.1 KiB
TypeScript

import { ref, onMounted, onUnmounted, type Ref } from 'vue'
const PLACEHOLDER = 'data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iMTYiIGhlaWdodD0iMTYiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PHJlY3Qgd2lkdGg9IjE2IiBoZWlnaHQ9IjE2IiBmaWxsPSIjMWExYTFhIi8+PC9zdmc+'
export function useLazyImage(imageRef: Ref<HTMLImageElement | null>, src: string) {
const isLoaded = ref(false)
const currentSrc = ref(PLACEHOLDER)
let observer: IntersectionObserver | null = null
function onLoad() {
isLoaded.value = true
}
onMounted(() => {
const el = imageRef.value
if (!el) return
observer = new IntersectionObserver(
(entries) => {
for (const entry of entries) {
if (entry.isIntersecting) {
currentSrc.value = src
el.src = src
el.addEventListener('load', onLoad, { once: true })
observer?.disconnect()
}
}
},
{ rootMargin: '200px' }
)
observer.observe(el)
})
onUnmounted(() => {
observer?.disconnect()
})
return { isLoaded, currentSrc, placeholder: PLACEHOLDER }
}