I am creating a chat using Ajax requests and I'm trying to get messages div to scroll to the bottom without much luck.
I am wrapping everything in this div:
#scroll {
height:400px;
overflow:scroll;
}
Is there a way to keep it scrolled to the bottom by default using JS?
Is there a way to keep it scrolled to the bottom after an ajax request?
This is much easier if you're using jQuery scrollTop:
$("#mydiv").scrollTop($("#mydiv")[0].scrollHeight);
You can try the code below:
function scrollToBottom (id) {
var div = document.getElementById(id);
div.scrollTop = div.scrollHeight - div.clientHeight;
}
To perform a smooth scroll with JQuery:
function scrollSmoothToBottom (id) {
var div = document.getElementById(id);
$('#' + id).animate({
scrollTop: div.scrollHeight - div.clientHeight
}, 500);
}
See the example on JSFiddle
Here's why this works:
Ref: scrollTop, scrollHeight, clientHeight
using jQuery animate:
$('#DebugContainer').stop().animate({
scrollTop: $('#DebugContainer')[0].scrollHeight
}, 800);
var mydiv = $("#scroll");
mydiv.scrollTop(mydiv.prop("scrollHeight"));
Works from jQuery 1.6
My Scenario: I had an list of string, in which I had to append a string given by a user and scroll to the end of the list automatically. I had fixed height of the display of the list, after which it should overflow.
I tried @Jeremy Ruten's answer, it worked, but it was scrolling to the (n-1)th element. If anybody is facing this type of issue, you can use setTimeOut() method workaround. You need to modify the code to below:
setTimeout(() => {
var objDiv = document.getElementById('div_id');
objDiv.scrollTop = objDiv.scrollHeight
}, 0)
Here is the StcakBlitz link I have created which shows the problem and its solution : https://stackblitz.com/edit/angular-ivy-x9esw8
Using jQuery, scrollTop is used to set the vertical position of scollbar for any given element. there is also a nice jquery scrollTo plugin used to scroll with animation and different options (demos)
var myDiv = $("#div_id").get(0);
myDiv.scrollTop = myDiv.scrollHeight;
if you want to use jQuery's animate method to add animation while scrolling down, check the following snippet:
var myDiv = $("#div_id").get(0);
myDiv.animate({
scrollTop: myDiv.scrollHeight
}, 500);
I have encountered the same problem, but with an additional constraint: I had no control over the code that appended new elements to the scroll container. None of the examples I found here allowed me to do just that. Here is the solution I ended up with .
It uses Mutation Observers (https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver) which makes it usable only on modern browsers (though polyfills exist)
So basically the code does just that :
var scrollContainer = document.getElementById("myId");
// Define the Mutation Observer
var observer = new MutationObserver(function(mutations) {
// Compute sum of the heights of added Nodes
var newNodesHeight = mutations.reduce(function(sum, mutation) {
return sum + [].slice.call(mutation.addedNodes)
.map(function (node) { return node.scrollHeight || 0; })
.reduce(function(sum, height) {return sum + height});
}, 0);
// Scroll to bottom if it was already scrolled to bottom
if (scrollContainer.clientHeight + scrollContainer.scrollTop + newNodesHeight + 10 >= scrollContainer.scrollHeight) {
scrollContainer.scrollTop = scrollContainer.scrollHeight;
}
});
// Observe the DOM Element
observer.observe(scrollContainer, {childList: true});
I made a fiddle to demonstrate the concept : https://jsfiddle.net/j17r4bnk/
Found this really helpful, thank you.
For the Angular 1.X folks out there:
angular.module('myApp').controller('myController', ['$scope', '$document',
function($scope, $document) {
var overflowScrollElement = $document[0].getElementById('your_overflow_scroll_div');
overflowScrollElement[0].scrollTop = overflowScrollElement[0].scrollHeight;
}
]);
Just because the wrapping in jQuery elements versus HTML DOM elements gets a little confusing with angular.
Also for a chat application, I found making this assignment after your chats were loaded to be useful, you also might need to slap on short timeout as well.
small addendum: scrolls only, if last line is already visible. if scrolled a tiny bit, leaves the content where it is (attention: not tested with different font sizes. this may need some adjustments inside ">= comparison"):
var objDiv = document.getElementById(id);
var doScroll=objDiv.scrollTop>=(objDiv.scrollHeight-objDiv.clientHeight);
// add new content to div
$('#' + id ).append("new line at end<br>"); // this is jquery!
// doScroll is true, if we the bottom line is already visible
if( doScroll) objDiv.scrollTop = objDiv.scrollHeight;
Just as a bonus snippet. I'm using angular and was trying to scroll a message thread to the bottom when a user selected different conversations with users. In order to make sure that the scroll works after the new data had been loaded into the div with the ng-repeat for messages, just wrap the scroll snippet in a timeout.
$timeout(function(){
var messageThread = document.getElementById('message-thread-div-id');
messageThread.scrollTop = messageThread.scrollHeight;
},0)
That will make sure that the scroll event is fired after the data has been inserted into the DOM.
On my Angular 6 application I just did this:
postMessage() {
// post functions here
let history = document.getElementById('history')
let interval
interval = setInterval(function() {
history.scrollTop = history.scrollHeight
clearInterval(interval)
}, 1)
}
The clearInterval(interval) function will stop the timer to allow manual scroll top / bottom.
Like you, I'm building a chat app and want the most recent message to scroll into view. This ultimately worked well for me:
//get the div that contains all the messages
let div = document.getElementById('message-container');
//make the last element (a message) to scroll into view, smoothly!
div.lastElementChild.scrollIntoView({ behavior: 'smooth' });
I know this is an old question, but none of these solutions worked out for me. I ended up using offset().top to get the desired results. Here's what I used to gently scroll the screen down to the last message in my chat application:
$("#html, body").stop().animate({
scrollTop: $("#last-message").offset().top
}, 2000);
I hope this helps someone else.
I use the difference between the Y coordinate of the first item div and the Y coordinate of the selected item div. Here is the JavaScript/JQuery code and the html:
function scrollTo(event){
// In my proof of concept, I had a few <button>s with value
// attributes containing strings with id selector expressions
// like "#item1".
let selectItem = $($(event.target).attr('value'));
let selectedDivTop = selectItem.offset().top;
let scrollingDiv = selectItem.parent();
let firstItem = scrollingDiv.children('div').first();
let firstItemTop = firstItem.offset().top;
let newScrollValue = selectedDivTop - firstItemTop;
scrollingDiv.scrollTop(newScrollValue);
}<div id="scrolling" style="height: 2rem; overflow-y: scroll">
<div id="item1">One</div>
<div id="item2">Two</div>
<div id="item3">Three</div>
<div id="item4">Four</div>
<div id="item5">Five</div>
</div>You can use the Element.scrollTo() method.
It can be animated using the built-in browser/OS animation, so it's super smooth.
function scrollToBottom() {
const scrollContainer = document.getElementById('container');
scrollContainer.scrollTo({
top: scrollContainer.scrollHeight,
left: 0,
behavior: 'smooth'
});
}
// initialize dummy content
const scrollContainer = document.getElementById('container');
const numCards = 100;
let contentInnerHtml = '';
for (let i=0; i<numCards; i++) {
contentInnerHtml += `<div class="card mb-2"><div class="card-body">Card ${i + 1}</div></div>`;
}
scrollContainer.innerHTML = contentInnerHtml;.overflow-y-scroll {
overflow-y: scroll;
}<link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet"/>
<div class="d-flex flex-column vh-100">
<div id="container" class="overflow-y-scroll flex-grow-1"></div>
<div>
<button class="btn btn-primary" onclick="scrollToBottom()">Scroll to bottom</button>
</div>
</div>If this is being done for scrolling to the bottom of chat window, do the following
The idea of scrolling to a particular div in the chat was the following
1) Each chat div consisting of Person, time and message is run in a for loop with class chatContentbox
2) querySelectorAll finds all such arrays. It could be 400 nodes (400 chats)
3) go to the last one
4) scrollIntoView()
let lastChatBox = document.querySelectorAll('.chatContentBox');
lastChatBox = lastChatBox[lastChatBox.length-1];
lastChatBox.scrollIntoView();
Sometimes the most simple is the best solution: I do not know if this will help, it helped me to scroll it were ever I wanted too. The higher the "y=" is,the more down it scrolls and of course "0" means top, so there for example "1000" could be bottom, or "2000" or "3000" and so on, depending how long your page is. This usually works in a button with onclick or onmouseover.
window.scrollTo(x=0,y=150);
