How to open Bootstrap dropdown programmatically

I'm trying to open a Bootstrap dropdown when I click a item of another dropdown.

The idea is to select a city from the first drop down - then the script will auto open the second dropdown with areas (and show only areas corresponding to the chosen city).

Here is my JS:

$('#sidebar_filter_city li').click(function(){   
    $('#sidebar_filter_areas').dropdown('toggle');
});

and this is the HTML:

<div class="dropdown form-control">
   <div data-toggle="dropdown" id="sidebar_filter_cities" class="sidebar_filter_menu" data-value="jersey-city">Jersey City<span class="caret caret_sidebar"></span></div>           
   <input type="hidden" name="advanced_city" value="jersey-city">
   <ul id="sidebar_filter_city" class="dropdown-menu filter_menu" role="menu" aria-labelledby="sidebar_filter_cities">
      <li role="presentation" data-value="">All Cities</li>
      <li role="presentation" data-value="jersey-city">Jersey City</li>
      <li role="presentation" data-value="london">London</li>
      <li role="presentation" data-value="new-york">New York</li>
   </ul>        
   </div>
</div>

<div class="dropdown form-control">
    <div data-toggle="dropdown" id="sidebar_filter_areas" class="sidebar_filter_menu">All Areas<span class="caret caret_sidebar"></span> </div>           
        <input type="hidden" name="advanced_area" value="">
           <ul id="sidebar_filter_area" class="dropdown-menu filter_menu" role="menu" aria-labelledby="sidebar_filter_areas">
               <li role="presentation" data-value="">All Areas</li>
               <li role="presentation" data-value="east-harlem" data-parentcity="">East Harlem</li>
               <li role="presentation" data-value="greenville" data-parentcity="">Greenville</li>
               <li role="presentation" data-value="manhattan" data-parentcity="">Manhattan</li>
               <li role="presentation" data-value="northern-brooklyn" data-parentcity="">Northern Brooklyn</li>
               
                  .....
           </ul>        
        </div>    
</div>

The best way is to check if the dropdown is not already open, and then to use .dropdown('toggle').

Couple things to be aware of:

• If you want to trigger it by clicking on another element, you must kill the click event on the other element- otherwise Bootstrap will treat it as a click outside of the dropdown and immediately close it.

• $('.dropdown').addClass('open') is not a good replacement for $('.dropdown-toggle').dropdown('toggle') as suggested in other answers, because it will cause the dropdown to stay permanently open instead of closing when you click off of the component.

HTML:

<button class="btn btn-secondary trigger_button">Trigger dropdown</button><br><br>
<div class="dropdown">
  <button class="btn btn-secondary dropdown-toggle" type="button" data-toggle="dropdown">
Dropdown
  </button>
  <div class="dropdown-menu">
  Stuff...
  </div>
</div>

JS:

$('.trigger_button').click(function(e){
  // Kill click event:
  e.stopPropagation();
  // Toggle dropdown if not already visible:
  if ($('.dropdown').find('.dropdown-menu').is(":hidden")){
    $('.dropdown-toggle').dropdown('toggle');
  }
});

Fiddle example

For Bootstrap 3 you can just add the 'open' class to the dropdown tag. Removing it closes the dropdown.

$('.dropdown').addClass('open'); // Opens the dropdown
$('.dropdown').removeClass('open'); // Closes it

This may work in other versions, but I'm not sure.

Bootstrap's dropdown plugin waits for 'click.bs.dropdown' event to show the menu, so in this case:

$('#sidebar_filter_areas').trigger('click.bs.dropdown');

should work. This will not trigger other 'click' events on same element if any.

dropdown('toggle') works great for me when using the button tag.

JS

$("#mybutton").dropdown('toggle')

HTML

<button class="dropdown-toggle ban" role="button" data-toggle="dropdown" data-target="#" id="mybutton">...</button>

You need to stop the click event from bubbling to parent elements

$('#sidebar_filter_city li').click(function(e){   
    $('#sidebar_filter_areas').dropdown('toggle');
    e.stopPropagation();
});

You can also use return false; which will do the same thing, but this will also preventDefault on the click.

If absolutely none of them are doing the trick, then you can do something like the following:

$('.dropdown').addClass('open'); // substitute with your own selector
$('.dropdown-toggle').attr('aria-expanded', true).focus(); // substitute with your own selector

Although the above will work, I do not recommend using it as it's a bit hacky.

Something I like to use that has a bit more user-expected behavior:

if(!$('#myDropdown').hasClass('show')){
  $('#myDropdown').dropdown('toggle');
}

If it is already open, don't do anything. If it is closed, then it should open.

This works for me.

$('.dropdown-toggle').click(function (ev) {
    ev.stopPropagation();

    $(this).parent().toggleClass('open');
});

Markup:

<div class="dropdown pull-right">
    <button class="btn btn-default dropdown-toggle task-actions" type="button"
            data-toggle="dropdown" aria-haspopup="true" aria-expanded="true">
        <img src="{{ asset('img/site/icons/menu.svg') }}" alt="Menu">
    </button>
    <ul id="dropdown-overview" class="dropdown-menu">
        <li><a href="#">Action</a></li>
        <li><a href="#">Another action</a></li>
        <li><a href="#">Something else here</a></li>
        <li role="separator" class="divider"></li>
        <li><a href="#">Separated link</a></li>
    </ul>
</div>

just use .click() on data-toggle element but do not forget e.stopPropagation()

these one simple line took me for hours, hope it's help :)

If you inspect opened drop down menu you can see selector which changes display of Dropdown menu. In bootstrap v3.0.0 css selector is:

.open > .dropdown-menu {
    display: block;
}

So open class should be added to parent node of element with .dropdown-menu class. In other versions if it has been changed probably correct selector can be found in the same way.

Try this:

$('#sidebar_filter_areas').click();

According to bootstrap docs you can simply use this :

$('.dropdown-toggle').dropdown();

For Bootstrap 4 using Anuglar 6 i used this:

<div class="dropdown-menu" id='logoutDropDownMenu' x-placement="bottom-start" style="position: absolute; transform: translate3d(0px, 40px, 0px); top: 0px; left: 0px; will-change: transform;">

My component ts file has this function

 import { DOCUMENT } from '@angular/common';
 import { Inject } from '@angular/core';

export class HomeComponent implements OnInit {

  private toggleLogout: boolean;

  constructor(@Inject(DOCUMENT) private document: any){}


 toggleButton() {
    if (this.toggleLogout) {
      this.document.getElementById('logoutDropDownMenu').classList.add('show');
    } else {
      this.document.getElementById('logoutDropDownMenu').classList.remove('show');
    }
    this.toggleLogout = !this.toggleLogout;

  }

in Bootstrap 4.x, following components need to be effected:

• li > .nav-item .dropdown
  • a > .nav-link > aria-expanded
• div > .dropdown-menu

Adding a click event listener, which triggers toggling a class and a bool value, for those classes make dropdown work with pure javascript as follows:

let status = false
const nav = document.getElementsByClassName('nav-item dropdown')[0]
nav.addEventListener('click', toggleDropdown)
function toggleDropdown () {
   if (status) {
      nav.classList.add('show')
      document.getElementsByClassName('nav-link dropdown-toggle')[0].setAttribute('aria-expanded', ' + status + ')
      document.getElementsByClassName('dropdown-menu').classList.add('show')
   } else {
      nav.classList.remove('show')
      document.getElementsByClassName('nav-link dropdown-toggle')[0].setAttribute('aria-expanded', ' + status + ')
      document.getElementsByClassName('dropdown-menu').classList.remove('show')
   }
   return status = !status
}

You can achieve the same thing using Native JavaScript like this:

 document.getElementById('XYZ').click('open');

It works on all browsers.

most of the time act as a manual action works :

$('#sidebar_filter_city li').click(function(){   
    $('#sidebar_filter_areas').click();
});

Add data-toggle="dropdown" id="dropbox" in HTML like this:

<div data-toggle="dropdown" id="dropbox" 

And in JS/TS:

$('#dropbox').trigger('click.bs.dropdown');

If you use a JS framework like AngularJS, you just need to implement your condition in JS (conditionMenuIsOpen()) and bind display styling of dropdown-menu with this condition in HTML. When condition is true, then display styling will change from hidden to block and the dropdown menu will appear.

<ul class="dropdown-menu" ng-style="vm.conditionMenuIsOpen() && {'display':'block'}">
  ...
</ul>