Detecting when user scrolls to bottom of div with React js

Question

I have a website with different sections. I am using segment.io to track different actions on the page. How can I detect if a user has scrolled to the bottom of a div? I hav

Answer 1

We can also detect div's scroll end by using ref.

import React, { Component } from 'react';
import {withRouter} from 'react-router-dom';
import styles from 'style.scss';

class Gallery extends Component{ 

  paneDidMount = (node) => {    
    if(node) {      
      node.addEventListener("scroll", this.handleScroll.bind(this));      
    }
  }

  handleScroll = (event) => {    
    var node = event.target;
    const bottom = node.scrollHeight - node.scrollTop === node.clientHeight;
    if (bottom) {      
      console.log("BOTTOM REACHED:",bottom); 
    }    
  }

  render() {
    var that = this;        
    return(<div className={styles.gallery}>
      <div ref={that.paneDidMount} className={styles.galleryContainer}>
        ...
      </div>

    </div>);   
  }
}

export default withRouter(Gallery);

Answer 2

I know this has already been answered but, I think another good solution is to use what's already available out in the open source community instead of DIY. React Waypoints is a library that exists to solve this very problem. (Though don't ask me why the this problem space of determining if a person scrolls past an HTML element is called "waypoints," haha)

I think it's very well designed with its props contract and definitely encourage you to check it out.

Answer 3

Here's a solution using React Hooks and ES6:

import React, { useRef, useEffect } from 'react';

const MyListComponent = () => {
  const listInnerRef = useRef();

  const onScroll = () => {
    if (listInnerRef.current) {
      const { scrollTop, scrollHeight, clientHeight } = listInnerRef.current;
      if (scrollTop + clientHeight === scrollHeight) {
        // TO SOMETHING HERE
        console.log('Reached bottom')
      }
    }
  };

  return (
    <div className="list">
      <div className="list-inner" onScroll={() => onScroll()} ref={listInnerRef}>
        {/* List items */}
      </div>
    </div>
  );
};

export default List;