javascript 42 lines · 7 steps

A responsive column hook in React

A custom hook that tracks viewport width and returns how many columns to render, with debounced, SSR-safe updates.

Explained by highlit
React Intermediate custom-hooks debouncing responsive-design cleanup ssr-safety
1import { useState, useEffect, useCallback } from 'react';
2 
3function getColumnCount(width) {
4 if (width < 640) return 1;
5 if (width < 1024) return 2;
6 if (width < 1440) return 3;
7 return 4;
8}
9 
10export function useResponsiveColumns() {
11 const [columns, setColumns] = useState(() =>
12 getColumnCount(typeof window !== 'undefined' ? window.innerWidth : 1440)
13 );
14 
15 const recompute = useCallback(() => {
16 setColumns((prev) => {
17 const next = getColumnCount(window.innerWidth);
18 return next === prev ? prev : next;
19 });
20 }, []);
21 
22 useEffect(() => {
23 let frame;
24 let timeout;
25 
26 const handleResize = () => {
27 clearTimeout(timeout);
28 timeout = setTimeout(() => {
29 frame = requestAnimationFrame(recompute);
30 }, 150);
31 };
32 
33 window.addEventListener('resize', handleResize);
34 return () => {
35 window.removeEventListener('resize', handleResize);
36 clearTimeout(timeout);
37 cancelAnimationFrame(frame);
38 };
39 }, [recompute]);
40 
41 return columns;
42}
01 / 01
STEP 01

Walkthrough

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Three takeaways
  1. 1A lazy state initializer lets you compute the first value once while guarding against undefined APIs during server rendering.
  2. 2Debouncing plus requestAnimationFrame keeps resize handlers cheap by collapsing bursts into a single paint-aligned update.
  3. 3Every listener and timer created in an effect should be torn down in its cleanup to avoid leaks and stale callbacks.

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