Bootstrap/docs/_includes/components/dropdowns.html

<div class="bs-docs-section">
  <h1 id="dropdowns" class="page-header">Dropdowns</h1>

  <p class="lead">Toggleable, contextual menu for displaying lists of links. Made interactive with the <a href="../javascript/#dropdowns">dropdown JavaScript plugin</a>.</p>

  <h3 id="dropdowns-example">Example</h3>
  <p>Wrap the dropdown's trigger and the dropdown menu within <code>.dropdown</code>, or another element that declares <code>position: relative;</code>. Then add the menu's HTML.</p>
  <div class="bs-example">
    <div class="dropdown clearfix">
      <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu1" data-toggle="dropdown">
        Dropdown
        <span class="caret"></span>
      </button>
      <ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu1">
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Action</a></li>
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Another action</a></li>
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Something else here</a></li>
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Separated link</a></li>
      </ul>
    </div>
  </div><!-- /example -->
{% highlight html %}
<div class="dropdown">
  <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu1" data-toggle="dropdown">
    Dropdown
    <span class="caret"></span>
  </button>
  <ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu1">
    <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Action</a></li>
    <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Another action</a></li>
    <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Something else here</a></li>
    <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Separated link</a></li>
  </ul>
</div>
{% endhighlight %}

  <h3 id="dropdowns-alignment">Alignment</h3>
  <p>By default, a dropdown menu is automatically positioned 100% from the top and along the left side of its parent. Add <code>.dropdown-menu-right</code> to a <code>.dropdown-menu</code> to right align the dropdown menu.</p>
  <div class="bs-callout bs-callout-warning">
    <h4>May require additional positioning</h4>
    <p>Dropdowns are automatically positioned via CSS within the normal flow of the document. This means dropdowns may be cropped by parents with certain <code>overflow</code> properties or appear out of bounds of the viewport. Address these issues on your own as they arise.</p>
  </div>
  <div class="bs-callout bs-callout-warning">
    <h4>Deprecated <code>.pull-right</code> alignment</h4>
    <p>As of v3.1.0, we've deprecated <code>.pull-right</code> on dropdown menus. To right-align a menu, use <code>.dropdown-menu-right</code>. Right-aligned nav components in the navbar use a mixin version of this class to automatically align the menu. To override it, use <code>.dropdown-menu-left</code>.</p>
  </div>
{% highlight html %}
<ul class="dropdown-menu dropdown-menu-right" role="menu" aria-labelledby="dLabel">
  ...
</ul>
{% endhighlight %}

  <h3 id="dropdowns-headers">Headers</h3>
  <p>Add a header to label sections of actions in any dropdown menu.</p>
  <div class="bs-example">
    <div class="dropdown clearfix">
      <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu2" data-toggle="dropdown">
        Dropdown
        <span class="caret"></span>
      </button>
      <ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu2">
        <li role="presentation" class="dropdown-header">Dropdown header</li>
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Action</a></li>
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Another action</a></li>
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Something else here</a></li>
        <li role="presentation" class="dropdown-header">Dropdown header</li>
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Separated link</a></li>
      </ul>
    </div>
  </div><!-- /example -->
{% highlight html %}
<ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu2">
  ...
  <li role="presentation" class="dropdown-header">Dropdown header</li>
  ...
</ul>
{% endhighlight %}

  <h3 id="dropdowns-divider">Divider</h3>
  <p>Add a divider to separate series of links in a dropdown menu.</p>
  <div class="bs-example">
    <div class="dropdown clearfix">
      <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu2" data-toggle="dropdown">
        Dropdown
        <span class="caret"></span>
      </button>
      <ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu2">
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Action</a></li>
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Another action</a></li>
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Something else here</a></li>
        <li role="presentation" class="divider"></li>
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Separated link</a></li>
      </ul>
    </div>
  </div><!-- /example -->
{% highlight html %}
<ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu2">
  ...
  <li role="presentation" class="divider"></li>
  ...
</ul>
{% endhighlight %}

  <h3 id="dropdowns-disabled">Disabled menu items</h3>
  <p>Add <code>.disabled</code> to a <code>&lt;li&gt;</code> in the dropdown to disable the link.</p>
  <div class="bs-example">
    <div class="dropdown clearfix">
      <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu3" data-toggle="dropdown">
        Dropdown
        <span class="caret"></span>
      </button>
      <ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu3">
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Regular link</a></li>
        <li role="presentation" class="disabled"><a role="menuitem" tabindex="-1" href="#">Disabled link</a></li>
        <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Another link</a></li>
      </ul>
    </div>
  </div><!-- /example -->
{% highlight html %}
<ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu3">
  <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Regular link</a></li>
  <li role="presentation" class="disabled"><a role="menuitem" tabindex="-1" href="#">Disabled link</a></li>
  <li role="presentation"><a role="menuitem" tabindex="-1" href="#">Another link</a></li>
</ul>
{% endhighlight %}
</div>