How can I use Zustand and ResizeObserver

Zustand is a lightweight and straightforward state management library designed for React applications. It is intuitive to use, with its simplicity and lightweight nature being key advantages. It supports TypeScript and integrates seamlessly with the React ecosystem.

Zustand Usage Example

First, install Zustand:

bash
npm install zustand

Then, create a store:

javascript
import create from 'zustand';

const useStore = create(set => ({
  count: 1,
  increment: () => set(state => ({ count: state.count + 1 })),
  decrement: () => set(state => ({ count: state.count - 1 }))
}));

Use the store in a component:

javascript
function Counter() {
  const { count, increment, decrement } = useStore();
  return (
    <div>
      <button onClick={decrement}>-</button>
      {count}
      <button onClick={increment}>+</button>
    </div>
  );
}

ResizeObserver Introduction

ResizeObserver allows you to listen for changes in the size of HTML elements. This is particularly useful for responsive design and layouts that depend on element dimensions.

ResizeObserver Usage Example

javascript
const ro = new ResizeObserver(entries => {
  for (let entry of entries) {
    const cr = entry.contentRect;
    console.log('Element:', entry.target);
    console.log(`Element size: ${cr.width}px x ${cr.height}px`);
    console.log(`Element padding: ${cr.top}px ; ${cr.left}px`);
  }
});

// Observe an element
ro.observe(document.getElementById('myElement'));

Combining Zustand and ResizeObserver

Suppose we want to update the Zustand store state based on changes in the size of an element within a React component. We can do this as follows:

1. Define the Zustand store: Store the width and height of the element.
2. Use ResizeObserver to listen for changes in the element's size: Update the Zustand store when the element's size changes.

javascript
import create from 'zustand';
import { useEffect } from 'react';

// Define store
const useSizeStore = create(set => ({
  width: 0,
  height: 0,
  setSize: (width, height) => set({ width, height })
}));

function ResponsiveComponent() {
  const { width, height, setSize } = useSizeStore();

  useEffect(() => {
    const ro = new ResizeObserver(entries => {
      for (let entry of entries) {
        const { width, height } = entry.contentRect;
        setSize(width, height);
      }
    });

    const element = document.getElementById('responsiveElement');
    ro.observe(element);

    return () => ro.disconnect(); // Cleanup
  }, [setSize]);

  return (
    <div id="responsiveElement">
      <p>The width is: {width}</p>
      <p>The height is: {height}</p>
    </div>
  );
}

Summary

By combining Zustand and ResizeObserver, we can easily manage state that depends on changes in element dimensions. This approach enhances the responsiveness and flexibility of React components.