c86c93582e
- Add 8 new skills (62 total, up from 58) - Official Anthropic skills: docx, pdf, pptx, xlsx, brand-guidelines, internal-comms - Vercel Labs skills: react-best-practices, web-design-guidelines - Implement dual-versioning: -official/-anthropic and -community suffixes - Update README with new skill registry and credits - Regenerate skills_index.json (62 skills validated) - Add comprehensive walkthrough.md BREAKING CHANGE: Document skills (docx/pdf/pptx/xlsx) renamed with version suffixes
1.9 KiB
1.9 KiB
title, impact, impactDescription, tags
| title | impact | impactDescription | tags |
|---|---|---|---|
| Batch DOM CSS Changes | MEDIUM | reduces reflows/repaints | javascript, dom, css, performance, reflow |
Batch DOM CSS Changes
Avoid changing styles one property at a time. Group multiple CSS changes together via classes or cssText to minimize browser reflows.
Incorrect (multiple reflows):
function updateElementStyles(element: HTMLElement) {
// Each line triggers a reflow
element.style.width = '100px'
element.style.height = '200px'
element.style.backgroundColor = 'blue'
element.style.border = '1px solid black'
}
Correct (add class - single reflow):
// CSS file
.highlighted-box {
width: 100px;
height: 200px;
background-color: blue;
border: 1px solid black;
}
// JavaScript
function updateElementStyles(element: HTMLElement) {
element.classList.add('highlighted-box')
}
Correct (change cssText - single reflow):
function updateElementStyles(element: HTMLElement) {
element.style.cssText = `
width: 100px;
height: 200px;
background-color: blue;
border: 1px solid black;
`
}
React example:
// Incorrect: changing styles one by one
function Box({ isHighlighted }: { isHighlighted: boolean }) {
const ref = useRef<HTMLDivElement>(null)
useEffect(() => {
if (ref.current && isHighlighted) {
ref.current.style.width = '100px'
ref.current.style.height = '200px'
ref.current.style.backgroundColor = 'blue'
}
}, [isHighlighted])
return <div ref={ref}>Content</div>
}
// Correct: toggle class
function Box({ isHighlighted }: { isHighlighted: boolean }) {
return (
<div className={isHighlighted ? 'highlighted-box' : ''}>
Content
</div>
)
}
Prefer CSS classes over inline styles when possible. Classes are cached by the browser and provide better separation of concerns.