How to create custom useInfiniteScroll Hook in React

Infinite scrolling is a popular technique used in web development to load content continuously as the user scrolls down a page. Implementing infinite scrolling efficiently can greatly improve user experience and performance.

In this blog post, we will explore how to create a custom useInfiniteScroll hook in React using Intersection Observer.

Implementation of useInfiniteScroll hook

const useInfiniteScroll = (callback) => {
    const observer = new IntersectionObserver((entries) => {
        if (entries[0].isIntersecting) {
            callback();
        }
    });

    useEffect(() => {
        observer.observe(document.getElementById('infinite-scroll-trigger'));

        return () => {
            observer.disconnect();
        };
    }, []);
};
    

Handle Infinite Scroll using custom useInfiniteScroll Hook

Next, let's use the useInfiniteScroll hook in a component to fetch more data as the user scrolls and reaches to the bottom of the page to fetch more content.

const InfiniteScrollComponent = () => {
    const [items, setItems] = useState([]);
    
    const fetchMoreData = () => {
        // Fetch more data and update the items state
    };

    useInfiniteScroll(fetchMoreData);

    return (
        <div>
            {items.map((item) => (
                <div key={item.id}>{item.name}</div>
            ))}
            <div id="infinite-scroll-trigger"></div>
        </div>
    );
};
    

Explanation

The useInfiniteScroll hook takes a callback function as an argument, which will be called when the target element (in this case, the trigger element) intersects with the viewport.

The hook sets up an Intersection Observer to monitor the trigger element and invoke the callback when it becomes visible.

In the InfiniteScrollComponent, we use the useInfiniteScroll hook to call the fetchMoreData function when the trigger element comes into view. This allows us to fetch more data and update the items state dynamically as the user scrolls.

Best Practices

• Loading state: Use a loading spinner or indicator while fetching more data to provide feedback to the user.
• Avoid Memory Leakage: Clean up the Intersection Observer when the component unmounts to prevent memory leaks.

Conclusion

Infinite scrolling can enhance the user experience by seamlessly loading content as the user interacts with the page. By implementing the useInfiniteScroll hook using Intersection Observer, you can efficiently handle long lists of items in your React applications.

Further Reading 🚀

1. Top 20 Most Asked Custom Hooks in React (Interview)
2. Best Resources to Ace React Interviews