How to Build an Infinite Scroll Component

Map over your main state data collection within JSX to output a structured feed list of child DOM components.

Insert a hidden structural marker node (like a loading indicator or 'sentinel' empty div) right underneath the rendered item feed group.

Create an Intersection Observer instance within a 'useEffect' hook: 'new IntersectionObserver(callback, options)' inside the component container.

Pass options config specifying a 'rootMargin' (e.g., '200px') to begin downloading data slightly before the user reaches the literal edge of the display container.

Write the logic inside your observer callback to capture tracking entries. Isolate 'entries[0].isIntersecting' to ensure the sentinel node has crossed the screen threshold.

Add validation clauses: check if the component is already in an active loading state or has hit the final data pagination ceiling before firing API loops.

Increment your local page index variable state tracker by 1. This updates dependencies and fires your async data aggregation method to retrieve next-generation rows.

Combine freshly resolved data with previous state elements using spread syntax: 'setItems(prev => [...prev, ...newItems])' to expand the continuous scrolling viewport.

Ensure the observer detaches cleanly using 'observer.disconnect()' or 'unobserve()' inside the hook's return statement to prevent background memory leaks.