twbs--bootstrap/docs/components/dropdowns.md

layout	title	group
docs	Dropdowns	components

Dropdowns are toggleable, contextual overlays for displaying lists of links and more. They're made interactive with the included Bootstrap dropdown JavaScript plugin.

Contents

• Will be replaced with the ToC, excluding the "Contents" header {:toc}

Example

Wrap the dropdown's trigger and the dropdown menu within .dropdown, or another element that declares position: relative;. Then, add the menu's HTML.

{% example html %}

Dropdown

• Action
• Another action
• Something else here

{% endexample %}

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 %}

{% highlight html %}

...

{% endhighlight %}

Menu headers

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

{% example html %}

• Dropdown header
• Action
• Another action

{% endexample %}

Menu dividers

Separate groups of related menu items with a divider.

{% example html %}

• Action
• Another action
• Something else here
• Separated link

{% endexample %}

Disabled menu items

Add .disabled to a <li> in the dropdown to disable the link.

{% example html %}

• Regular link
• Disabled link
• Another link

{% 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 %}

Dropdown trigger

...

{% endhighlight %}

To keep URLs intact with link buttons, use the data-target attribute instead of href="#".

{% highlight html %}

Dropdown trigger

...

{% endhighlight %}

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 %}