Detecting when user scrolls to bottom of div with React js

Viewed 140303

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 have tried the following but it seems to be triggered as soon as I scroll on the page and not when I reached the bottom of the div.

componentDidMount() {
  document.addEventListener('scroll', this.trackScrolling);
}

trackScrolling = () => {
  const wrappedElement = document.getElementById('header');
  if (wrappedElement.scrollHeight - wrappedElement.scrollTop === wrappedElement.clientHeight) {
    console.log('header bottom reached');
    document.removeEventListener('scroll', this.trackScrolling);
  }
};
11 Answers

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;

This answer belongs to Brendan, let's make it functional

export default () => {
   const handleScroll = (e) => {
       const bottom = e.target.scrollHeight - e.target.scrollTop === e.target.clientHeight;
       if (bottom) { 
           console.log("bottom")
       }
    }

  return (
     <div onScroll={handleScroll}  style={{overflowY: 'scroll', maxHeight: '400px'}}  >
        //overflowing elements here
   </div>
  )
}

If the first div is not scrollable it won't work and onScroll didn't work for me in a child element like div after the first div so onScroll should be at the first HTML tag that has an overflow

Extending chandresh's answer to use react hooks and ref I would do it like this;

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

export default function Scrollable() {
    const [referenceNode, setReferenceNode] = useState();
    const [listItems] = useState(Array.from(Array(30).keys(), (n) => n + 1));

    useEffect(() => {
        return () => referenceNode.removeEventListener('scroll', handleScroll);
    }, []);

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

    const paneDidMount = (node) => {
        if (node) {
            node.addEventListener('scroll', handleScroll);
            setReferenceNode(node);
        }
    };

    return (
        <div
            ref={paneDidMount}
            style={{overflowY: 'scroll', maxHeight: '400px'}}
        >
            <ul>
                {listItems.map((listItem) => <li>List Item {listItem}</li>)}
            </ul>
        </div>
    );
}

Add following functions in your React.Component and you're done :]

  componentDidMount() {
    window.addEventListener("scroll", this.onScroll, false);
  }

  componentWillUnmount() {
    window.removeEventListener("scroll", this.onScroll, false);
  }

  onScroll = () => {
    if (this.hasReachedBottom()) {
      this.props.onScrollToBottom();
    }
  };

  hasReachedBottom() {
    return (
      document.body.offsetHeight + document.body.scrollTop ===
      document.body.scrollHeight
    );
  }

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.

I used follow in my code

.modify-table-wrap {
    padding-top: 50px;
    height: 100%;
    overflow-y: scroll;
}

And add code in target js

    handleScroll = (event) => {
        const { limit, offset } = this.state
        const target = event.target
        if (target.scrollHeight - target.scrollTop === target.clientHeight) {
            this.setState({ offset: offset + limit }, this.fetchAPI)
        }
    }
    return (
            <div className="modify-table-wrap" onScroll={this.handleScroll}>
               ...
            <div>
            )

To evaluate whether my browser has scrolled to the bottom of a div, I settled with this solution:

const el = document.querySelector('.your-element');
const atBottom = Math.ceil(el.scrollTop + el.offsetHeight) === el.scrollHeight;

Put a div with 0 height after your scrolling div. then use this custom hooks to detect if this div is visible.

  const bottomRef = useRef();
  const reachedBottom = useCustomHooks(bottomRef);

  return(
  <div>
   {search resault}
  </div>
  <div ref={bottomRef}/> )

reachedBottom will toggle to true if you reach bottom

Related