What's the purpose of dropdown-toggle class in bootstrap dropdowns?
The dropdown-toggle
class adds the outline: 0;
on :focus
to the button, so when you click on the button it will not have the surrounding blue border of the "active" element.
Check the next two bottons:
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<div class="container">
<h2>Dropdowns</h2>
<p>The .divider class is used to separate links inside the dropdown menu with a thin horizontal line:</p>
<div class="dropdown">
<button class="btn btn-default dropdown-toggle" type="button" data-toggle="dropdown">Tutorials - no border
<span class="caret"></span></button>
<ul class="dropdown-menu">
<li><a href="#">HTML</a></li>
<li><a href="#">CSS</a></li>
<li><a href="#">JavaScript</a></li>
<li class="divider"></li>
<li><a href="#">About Us</a></li>
</ul>
</div>
</div>
<div class="container">
<h2>Dropdowns</h2>
<p>The .divider class is used to separate links inside the dropdown menu with a thin horizontal line:</p>
<div class="dropdown">
<button class="btn btn-default" type="button" data-toggle="dropdown">Tutorials - with border
<span class="caret"></span></button>
<ul class="dropdown-menu">
<li><a href="#">HTML</a></li>
<li><a href="#">CSS</a></li>
<li><a href="#">JavaScript</a></li>
<li class="divider"></li>
<li><a href="#">About Us</a></li>
</ul>
</div>
</div>
It adds the following CSS properties, but they impact when dropdown button's content is displayed:
It's basically some button
inner box-shadow
when .open
, as well as color
, background-color
, border-color
and outline
(on :focus
) removal. Here a comparison between the two:
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<!-- Single button -->
<div class="btn-group">
<button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
With .dropdown-toggle <span class="caret"></span>
</button>
<ul 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>
<!-- Single button -->
<div class="btn-group">
<button type="button" class="btn btn-default" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Without .dropdown-toggle <span class="caret"></span>
</button>
<ul 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>
Difference tested in Chrome, Opera & Safari: