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| layout | title | group |
|---|---|---|
| docs | Dropdowns | components |
[//]: # DO NOT EDIT IT WILL BE OVERWRITTEN - copy of bootstrap documentation generated by gulp docs:copy:bs-docs
{% callout info %} Bootstrap Reference Documentation This is a part of the reference documentation from Bootstrap. It is included here to demonstrate rendering with Bootstrap Material Design default styling. See the Material Design section for more elements and customization options. {% endcallout %}
Dropdowns are toggleable, contextual overlays for displaying lists of links and more. They're made interactive with the included Bootstrap dropdown JavaScript plugin. They're toggled by clicking, not by hovering; this is an intentional design decision.
Contents
- Will be replaced with the ToC, excluding the "Contents" header {:toc}
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:
{% example html %}
And with <a> elements:
{% example html %}
{% endexample %}The best part is you can do this with any button variant, too:
{% highlight html %}
{% endhighlight %}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.
{% highlight html %}
Sizing
Button dropdowns work with buttons of all sizes, including default and split dropdown buttons.
{% highlight html %}
Dropup variation
Trigger dropdown menus above elements by adding .dropup to the parent element.
<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">
<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>
{% highlight html %}
Menu items
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.
{% example html %}
Menu alignment
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.
{% callout info %} Heads up! Dropdowns are positioned only with CSS and may need some additional styles for exact alignment. {% endcallout %}
{% example html %}
Menu headers
Add a header to label sections of actions in any dropdown menu.
{% example html %}
{% endexample %}Menu dividers
Separate groups of related menu items with a divider.
{% example html %}
{% endexample %}Disabled menu items
Add .disabled to items in the dropdown to style them as disabled.
{% example html %}
{% endexample %}Usage
Via data attributes or JavaScript, the dropdown plugin toggles hidden content (dropdown menus) by toggling the .open class on the parent list item.
On mobile devices, opening a dropdown adds a .dropdown-backdrop as a tap area for closing dropdown menus when tapping outside the menu, a requirement for proper iOS support. This means that switching from an open dropdown menu to a different dropdown menu requires an extra tap on mobile.
Note: 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.
Via data attributes
Add data-toggle="dropdown" to a link or button to toggle a dropdown.
{% highlight html %}
To keep URLs intact with link buttons, use the data-target attribute instead of href="#".
{% highlight html %}
Via JavaScript
Call the dropdowns via JavaScript:
{% highlight js %} $('.dropdown-toggle').dropdown() {% endhighlight %}
{% callout info %}
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.
{% endcallout %}
Options
None.
Methods
| Method | Description |
|---|---|
$().dropdown('toggle') |
Toggles the dropdown menu of a given navbar or tabbed navigation. |
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). |
{% highlight js %} $('#myDropdown').on('show.bs.dropdown', function () { // do something… }) {% endhighlight %}