Dropdowns

Toggle contextual overlays for displaying lists of links and more with the Boosted dropdown plugin.

Overview

Dropdowns are toggleable, contextual overlays for displaying lists of links and more. They’re made interactive with the included Boosted dropdown JavaScript plugin. They’re toggled by clicking, not by hovering; this is an intentional design decision.

Dropdowns are built on a third party library, Popper.js, which provides dynamic positioning and viewport detection. Be sure to include popper.min.js before Boosted’s JavaScript or use boosted.bundle.min.js / boosted.bundle.js which contains Popper.js. Popper.js isn’t used to position dropdowns in navbars though as dynamic positioning isn’t required.

If you’re building our JavaScript from source, it requires util.js.

Accessibility

The WAI ARIA standard defines an actual role="menu" widget, but this is specific to application-like menus which trigger actions or functions. ARIA menus can only contain menu items, checkbox menu items, radio button menu items, radio button groups, and sub-menus.

Boosted’s dropdowns, on the other hand, are designed to be generic and applicable to a variety of situations and markup structures. For instance, it is possible to create dropdowns that contain additional inputs and form controls, such as search fields or login forms. For this reason, Boosted does not expect (nor automatically add) any of the role and aria- attributes required for true ARIA menus. Authors will have to include these more specific attributes themselves.

However, Boosted does add built-in support for most standard keyboard menu interactions, such as the ability to move through individual .dropdown-item elements using the cursor keys and close the menu with the ESC key.

Examples

Wrap the dropdown’s toggle (your button or link) and the dropdown menu within .dropdown, or another element that declares position: relative;. Dropdowns can be triggered from <a> or <button> elements to better fit your potential needs.

Single button dropdowns

Any single .btn can be turned into a dropdown toggle with some markup changes. Here’s how you can put them to work with either <button> elements:

<div class="dropdown">
  <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropdown button
  </button>
  <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
    <a class="dropdown-item" href="#">Action</a>
    <a class="dropdown-item" href="#">Another action</a>
    <a class="dropdown-item" href="#">Something else here</a>
  </div>
</div>

And with <a> elements:

<div class="dropdown show">
  <a class="btn btn-secondary dropdown-toggle" href="#" role="button" id="dropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropdown link
  </a>

  <div class="dropdown-menu" aria-labelledby="dropdownMenuLink">
    <a class="dropdown-item" href="#">Action</a>
    <a class="dropdown-item" href="#">Another action</a>
    <a class="dropdown-item" href="#">Something else here</a>
  </div>
</div>

The best part is you can do this with any button variant, too:

<!-- Example single danger button -->
<div class="btn-group">
  <button type="button" class="btn btn-danger dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Action
  </button>
  <div class="dropdown-menu">
    <a class="dropdown-item" href="#">Action</a>
    <a class="dropdown-item" href="#">Another action</a>
    <a class="dropdown-item" href="#">Something else here</a>
    <div class="dropdown-divider"></div>
    <a class="dropdown-item" href="#">Separated link</a>
  </div>
</div>

Split button dropdowns

Similarly, create split button dropdowns with virtually the same markup as single button dropdowns, but with the addition of .dropdown-toggle-split for proper spacing around the dropdown caret.

We use this extra class to reduce the horizontal padding on either side of the caret by 25% and remove the margin-left that’s added for regular button dropdowns. Those extra changes keep the caret centered in the split button and provide a more appropriately sized hit area next to the main button.

<!-- Example split danger button -->
<div class="btn-group">
  <button type="button" class="btn btn-danger">Action</button>
  <button type="button" class="btn btn-danger dropdown-toggle dropdown-toggle-split" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    <span class="sr-only">Toggle Dropdown</span>
  </button>
  <div class="dropdown-menu">
    <a class="dropdown-item" href="#">Action</a>
    <a class="dropdown-item" href="#">Another action</a>
    <a class="dropdown-item" href="#">Something else here</a>
    <div class="dropdown-divider"></div>
    <a class="dropdown-item" href="#">Separated link</a>
  </div>
</div>

Sizing

Button dropdowns work with buttons of all sizes, including default and split dropdown buttons.

<!-- Large button groups (default and split) -->
<div class="btn-group">
  <button class="btn btn-secondary btn-lg dropdown-toggle" type="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Large button
  </button>
  <div class="dropdown-menu">
    ...
  </div>
</div>
<div class="btn-group">
  <button class="btn btn-secondary btn-lg" type="button">
    Large button
  </button>
  <button type="button" class="btn btn-lg btn-secondary dropdown-toggle dropdown-toggle-split" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    <span class="sr-only">Toggle Dropdown</span>
  </button>
  <div class="dropdown-menu">
    ...
  </div>
</div>

<!-- Small button groups (default and split) -->
<div class="btn-group">
  <button class="btn btn-secondary btn-sm dropdown-toggle" type="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Small button
  </button>
  <div class="dropdown-menu">
    ...
  </div>
</div>
<div class="btn-group">
  <button class="btn btn-secondary btn-sm" type="button">
    Small button
  </button>
  <button type="button" class="btn btn-sm btn-secondary dropdown-toggle dropdown-toggle-split" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    <span class="sr-only">Toggle Dropdown</span>
  </button>
  <div class="dropdown-menu">
    ...
  </div>
</div>

Dropup variation

Trigger dropdown menus above elements by adding .dropup to the parent element.

<!-- Default dropup button -->
<div class="btn-group dropup">
  <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropup
  </button>
  <div class="dropdown-menu">
    <!-- Dropdown menu links -->
  </div>
</div>

<!-- Split dropup button -->
<div class="btn-group dropup">
  <button type="button" class="btn btn-secondary">
    Split dropup
  </button>
  <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    <span class="sr-only">Toggle Dropdown</span>
  </button>
  <div class="dropdown-menu">
    <!-- Dropdown menu links -->
  </div>
</div>

Dropright variation

Trigger dropdown menus at the right of the elements by adding .dropright to the parent element.

<!-- Default dropright button -->
<div class="btn-group dropright">
  <button type="button" class="btn btn-secondary">Dropright</button>
  <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    <span class="sr-only">Toggle Dropright</span>
  </button>
  <div class="dropdown-menu">
    <!-- Dropdown menu links -->
  </div>
</div>

<!-- Split dropright button -->
<div class="btn-group dropright">
  <button type="button" class="btn btn-secondary">
    Split dropright
  </button>
  <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    <span class="sr-only">Toggle Dropright</span>
  </button>
  <div class="dropdown-menu">
    <!-- Dropdown menu links -->
  </div>
</div>

Dropleft variation

Trigger dropdown menus at the left of the elements by adding .dropleft to the parent element.

<!-- Default dropleft button -->
<div class="btn-group dropleft">
  <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropleft
  </button>
  <div class="dropdown-menu">
    <!-- Dropdown menu links -->
  </div>
</div>

<!-- Split dropleft button -->
<div class="btn-group">
  <div class="btn-group dropleft" role="group">
    <button type="button" class="btn btn-secondary dropdown-toggle dropdown-toggle-split" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
      <span class="sr-only">Toggle Dropleft</span>
    </button>
    <div class="dropdown-menu">
      <!-- Dropdown menu links -->
    </div>
  </div>
  <button type="button" class="btn btn-secondary">
    Split dropleft
  </button>
</div>

Historically dropdown menu contents had to be links, but that’s no longer the case with v4. Now you can optionally use <button> elements in your dropdowns instead of just <a>s.

<div class="dropdown">
  <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenu2" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropdown
  </button>
  <div class="dropdown-menu" aria-labelledby="dropdownMenu2">
    <button class="dropdown-item" type="button">Action</button>
    <button class="dropdown-item" type="button">Another action</button>
    <button class="dropdown-item" type="button">Something else here</button>
  </div>
</div>

By default, a dropdown menu is automatically positioned 100% from the top and along the left side of its parent. Add .dropdown-menu-right to a .dropdown-menu to right align the dropdown menu.

Heads up! Dropdowns are positioned thanks to Popper.js (except when they are contained in a navbar).

<div class="btn-group">
  <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Right-aligned menu
  </button>
  <div class="dropdown-menu dropdown-menu-right">
    <button class="dropdown-item" type="button">Action</button>
    <button class="dropdown-item" type="button">Another action</button>
    <button class="dropdown-item" type="button">Something else here</button>
  </div>
</div>

Add a header to label sections of actions in any dropdown menu.

<div class="dropdown-menu">
  <h6 class="dropdown-header">Dropdown header</h6>
  <a class="dropdown-item" href="#">Action</a>
  <a class="dropdown-item" href="#">Another action</a>
</div>

Separate groups of related menu items with a divider.

<div class="dropdown-menu">
  <a class="dropdown-item" href="#">Action</a>
  <a class="dropdown-item" href="#">Another action</a>
  <a class="dropdown-item" href="#">Something else here</a>
  <div class="dropdown-divider"></div>
  <a class="dropdown-item" href="#">Separated link</a>
</div>

Put a form within a dropdown menu, or make it into a dropdown menu, and use margin or padding utilities to give it the negative space you require.

<div class="dropdown-menu">
  <form class="px-3 py-3">
    <div class="form-group">
      <label for="exampleDropdownFormEmail1">Email address</label>
      <input type="email" class="form-control" id="exampleDropdownFormEmail1" placeholder="email@example.com">
    </div>
    <div class="form-group">
      <label for="exampleDropdownFormPassword1">Password</label>
      <input type="password" class="form-control" id="exampleDropdownFormPassword1" placeholder="Password">
    </div>
    <div class="form-check">
      <input type="checkbox" class="form-check-input" id="dropdownCheck">
      <label class="form-check-label" for="dropdownCheck">
        Remember me
      </label>
    </div>
    <button type="submit" class="btn btn-primary">Sign in</button>
  </form>
  <div class="dropdown-divider"></div>
  <a class="dropdown-item" href="#">New around here? Sign up</a>
  <a class="dropdown-item" href="#">Forgot password?</a>
</div>

<form class="dropdown-menu p-4">
  <div class="form-group">
    <label for="exampleDropdownFormEmail2">Email address</label>
    <input type="email" class="form-control" id="exampleDropdownFormEmail2" placeholder="email@example.com">
  </div>
  <div class="form-group">
    <label for="exampleDropdownFormPassword2">Password</label>
    <input type="password" class="form-control" id="exampleDropdownFormPassword2" placeholder="Password">
  </div>
  <div class="form-check">
    <input type="checkbox" class="form-check-input" id="dropdownCheck2">
    <label class="form-check-label" for="dropdownCheck2">
      Remember me
    </label>
  </div>
  <button type="submit" class="btn btn-primary">Sign in</button>
</form>

Add .disabled to items in the dropdown to style them as disabled.

<div class="dropdown-menu">
  <a class="dropdown-item" href="#">Regular link</a>
  <a class="dropdown-item disabled" href="#">Disabled link</a>
  <a class="dropdown-item" href="#">Another link</a>
</div>

Usage

Via data attributes or JavaScript, the dropdown plugin toggles hidden content (dropdown menus) by toggling the .show class on the parent list item. The data-toggle="dropdown" attribute is relied on for closing dropdown menus at an application level, so it’s a good idea to always use it.

On touch-enabled devices, opening a dropdown adds empty ($.noop) mouseover handlers to the immediate children of the <body> element. This admittedly ugly hack is necessary to work around a quirk in iOS’ event delegation, which would otherwise prevent a tap anywhere outside of the dropdown from triggering the code that closes the dropdown. Once the dropdown is closed, these additional empty mouseover handlers are removed.

Via data attributes

Add data-toggle="dropdown" to a link or button to toggle a dropdown.

<div class="dropdown">
  <button id="dLabel" type="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropdown trigger
  </button>
  <div class="dropdown-menu" aria-labelledby="dLabel">
    ...
  </div>
</div>

Via JavaScript

Call the dropdowns via JavaScript:

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

`data-toggle="dropdown"` still required

Regardless of whether you call your dropdown via JavaScript or instead use the data-api, data-toggle="dropdown" is always required to be present on the dropdown’s trigger element.

Options

Options can be passed via data attributes or JavaScript. For data attributes, append the option name to data-, as in data-offset="".

Name	Type	Default	Description
offset	number \| string \| function	0	Offset of the dropdown relative to its target. For more information refer to Popper.js's offset docs.
flip	boolean	true	Allow Dropdown to flip in case of an overlapping on the reference element. For more information refer to Popper.js's flip docs.
boundary	string \| element	'scrollParent'	Overflow constraint boundary of the dropdown menu. Accepts the values of `'viewport'`, `'window'`, `'scrollParent'`, or an HTMLElement reference (JavaScript only). For more information refer to Popper.js's preventOverflow docs.

Note when boundary is set to any value other than 'scrollParent', the style position: static is applied to the .dropdown container.

Methods

Method	Description
`$().dropdown('toggle')`	Toggles the dropdown menu of a given navbar or tabbed navigation.
`$().dropdown('update')`	Updates the position of an element’s dropdown.
`$().dropdown('dispose')`	Destroys an element’s dropdown.

Events

All dropdown events are fired at the .dropdown-menu’s parent element and have a relatedTarget property, whose value is the toggling anchor element.

Event	Description
`show.bs.dropdown`	This event fires immediately when the show instance method is called.
`shown.bs.dropdown`	This event is fired when the dropdown has been made visible to the user (will wait for CSS transitions, to complete).
`hide.bs.dropdown`	This event is fired immediately when the hide instance method has been called.
`hidden.bs.dropdown`	This event is fired when the dropdown has finished being hidden from the user (will wait for CSS transitions, to complete).

$('#myDropdown').on('show.bs.dropdown', function () {
  // do something…
})

Dropdowns

Overview

Accessibility

Examples

Single button dropdowns

Split button dropdowns

Sizing

Dropup variation

Dropright variation

Dropleft variation

Menu items

Menu alignment

Menu headers

Menu dividers

Menu forms

Disabled menu items

Usage

Via data attributes

Via JavaScript

`data-toggle="dropdown"` still required

Options

Methods

Events

Dropdowns

Overview

Accessibility

Examples

Single button dropdowns

Split button dropdowns

Sizing

Dropup variation

Dropright variation

Dropleft variation

Menu items

Menu alignment

Menu headers

Dropdown header

Menu dividers

Menu forms

Disabled menu items

Usage

Via data attributes

Via JavaScript

data-toggle="dropdown" still required

Options

Methods

Events

`data-toggle="dropdown"` still required