How to keep scroll bar always on bottom of chat

Question

I have a chat box and i have to keep scroll bar always on bottom of chat also if there is a new message coming scroll bar automatically scroll to bottom. The code i am using scrolled chat box only half also when a new message popup it doesn't scroll to bottom.

$('#chat_history_'+to_user_id).stop().animate({ scrollTop: $('#chat_history_'+to_user_id)[0].scrollHeight}, 1000);

Answer 1

This is your Solution

 window.alert = function(){};
        var defaultCSS = document.getElementById('bootstrap-css');
        function changeCSS(css){
            if(css) $('head > link').filter(':first').replaceWith('<link rel="stylesheet" href="'+ css +'" type="text/css" />'); 
            else $('head > link').filter(':first').replaceWith(defaultCSS); 
        }
        
$("#submit").click(function() {
    var data = $("#btn-input").val();
        //console.log(data);
        $('chat_log').append('<div class="row msg_container base_sent"><div class="col-md-10 col-xs-10"><div class="messages msg_receive"><p>'+data+'</p></div></div></div><div class="row msg_container base_receive"><div class="col-md-10 col-xs-10"><div class="messages msg_receive"><p>'+data+'</p></div></div></div>');
        clearInput();
        $(".msg_container_base").stop().animate({ scrollTop: $(".msg_container_base")[0].scrollHeight}, 1000);
});

function clearInput() {
    $("#myForm :input").each(function() {
        $(this).val(''); //hide form values
    });
}

$("#myForm").submit(function() {
    return false; //to prevent redirection to save.php
});

.msg_container_base{
  background: #e5e5e5;
  margin: 0;
  padding: 0 10px 10px;
  max-height:80vh;
  overflow-x:hidden;
}
.top-bar {
  background: #666;
  color: white;
  padding: 10px;
  position: relative;
  overflow: hidden;
}
.msg_receive{
    padding-left:0;
    margin-left:0;
}
.msg_sent{
    padding-bottom:20px !important;
    margin-right:0;
}
.messages {
  background: white;
  padding: 10px;
  border-radius: 2px;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
  max-width:100%;
}
.messages > p {
    font-size: 13px;
    margin: 0 0 0.2rem 0;
  }
.messages > time {
    font-size: 11px;
    color: #ccc;
}
.msg_container {
    padding: 10px;
    overflow: hidden;
    display: flex;
}
img {
    display: block;
    width: 100%;
}
.avatar {
    position: relative;
}
.base_receive > .avatar:after {
    content: "";
    position: absolute;
    top: 0;
    right: 0;
    width: 0;
    height: 0;
    border: 5px solid #FFF;
    border-left-color: rgba(0, 0, 0, 0);
    border-bottom-color: rgba(0, 0, 0, 0);
}

.base_sent {
  justify-content: flex-end;
  align-items: flex-end;
}
.base_sent > .avatar:after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 0;
    border: 5px solid white;
    border-right-color: transparent;
    border-top-color: transparent;
    box-shadow: 1px 1px 2px rgba(black, 0.2); // not quite perfect but close
}

.msg_sent > time{
    float: right;
}



.msg_container_base::-webkit-scrollbar-track
{
    -webkit-box-shadow: inset 0 0 6px rgba(0,0,0,0.3);
    background-color: #F5F5F5;
}

.msg_container_base::-webkit-scrollbar
{
    width: 12px;
    background-color: #F5F5F5;
}

.msg_container_base::-webkit-scrollbar-thumb
{
    -webkit-box-shadow: inset 0 0 6px rgba(0,0,0,.3);
    background-color: #555;
}

.btn-group.dropup{
    position:fixed;
    left:0px;
    bottom:0;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="panel panel-primary" style="border:0px">
                <div class="panel-heading top-bar">
                    <div class="col-md-8 col-xs-8">
                        <h3 class="panel-title"><span class="glyphicon glyphicon-comment" style="margin-right:6px;"></span>College Enquiry Chat</h3>
                    </div>
                </div>


                <div class="panel-body msg_container_base">

                    <div class="row msg_container base_sent">
                        <div class="col-md-10 col-xs-10">
                            <div class="messages msg_sent">
                                <p>that mongodb thing looks good, huh?
                                tiny master db, and huge document store</p>
                            </div>
                        </div>
                    </div>

                    <div class="row msg_container base_receive">
                        <div class="col-md-10 col-xs-10">
                            <div class="messages msg_receive">
                                <p>that mongodb thing looks good, huh?
                                tiny master db, and huge document store</p>
                            </div>
                        </div>
                    </div>

                    <chat_log> . </chat_log>
                </div>

                <!--CHAT USER BOX-->
                <div class="panel-footer">
                    <div class="input-group" id="myForm">
                        <input id="btn-input" type="text" class="form-control input-sm chat_input" placeholder="Write your message here...">
                        <span class="input-group-btn">
                        <button class="btn btn-primary btn-sm" id="submit" type="submit">Send</button>
                        </span>
                    </form>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

See Code link