Bootstrap 3 vertical menu with toggable submenus

Question

Using Bootstrap 3, I need to construct a vertical menu containing toggable submenus. I have the following structure:

<nav>
    <ul>
        <li><a href="#">Item 1</a></li>
        <li><a href="#">Item 2 (toggle)</a>
            <ul>
                <li><a href="#">Item 2.1</a></li>
                <li><a href="#">Item 2.2</a></li>
                <li><a href="#">Item 2.3</a></li>
            </ul>
        </li>
        <li><a href="#">Item 3</a></li>
        <li><a href="#">Item 4</a></li>
    </ul>
</nav>

I want the UL inside "Item 2" to be hidden by default and unhide/hide it by pressing "Item 2".

Answer 1

The key of making a vertical submenu toggable is to use the attribute data-toggle="collapse" instead of the most common used in navs data-toggle="dropdown".

I prepared this jsfiddle example, and this is the wordking code:

<nav>
    <ul class="nav">
      <li><a href="#">Link 1</a></li>
    <li><a href="#" id="btn-1" data-toggle="collapse" data-target="#submenu1" aria-expanded="false">Link 2 (toggle)</a>
      <ul class="nav collapse" id="submenu1" role="menu" aria-labelledby="btn-1">
        <li><a href="#">Link 2.1</a></li>
        <li><a href="#">Link 2.2</a></li>
        <li><a href="#">Link 2.3</a></li>
      </ul>
    </li>
    <li><a href="#">Link 3</a></li>
    <li><a href="#">Link 4</a></li>
  </ul>
</nav>

Answer 2

Sometimes you need both a menu item link and a toggle for submenu items.

Here is a test:

/* CSS */

.toggle-custom {
  position: absolute !important;
  top: 0;
  right: 0;
}
.toggle-custom[aria-expanded='true'] .glyphicon-plus:before {
  content: "\2212";
}

<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.1/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://code.jquery.com/jquery-1.11.1.min.js" type="text/javascript" ></script>
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.1/js/bootstrap.min.js" type="text/javascript" ></script>

<nav>
  <ul class="nav">
    <li><a href="#">Link 1</a>
    </li>
    <li><a href="#">Link 2</a><a href="#" class="toggle-custom" id="btn-1" data-toggle="collapse" data-target="#submenu1" aria-expanded="false"><span class="glyphicon glyphicon-plus" aria-hidden="true"></span></a>
      <ul class="nav collapse" id="submenu1" role="menu" aria-labelledby="btn-1">
        <li><a href="#">Link 2.1</a>
        </li>
        <li><a href="#">Link 2.2</a>
        </li>
        <li><a href="#">Link 2.3</a>
        </li>
      </ul>
    </li>
    <li><a href="#">Link 3</a>
    </li>
  </ul>
</nav>

http://jsfiddle.net/zoxqpftc/461/

Answer 3

For future readers using newer Bootstrap 5 (update 2021).. The Collapse component can still be used along with the Nav component.

If you want the menu to have an accordion effect (only one item open at a time) use the data-bs-parent attribute to set the parent of each menu section..

<div class="nav flex-column">
    <a href="#menu1" class="nav-link collapsed" data-bs-toggle="collapse" role="button">Item 1 ▾</a>
    <div class="collapse ps-2" id="menu1" data-bs-parent="#sidebar">
        <a href="#menu1sub1" class="nav-link" data-bs-toggle="collapse" aria-expanded="false">Subitem1 1 ▾</a>
        <div class="collapse ps-2" id="menu1sub1" data-bs-parent="#menu1">
            <a href="#" class="nav-link" data-bs-parent="#menu1sub1">Subitem a</a>
            <a href="#" class="nav-link" data-bs-parent="#menu1sub1">Subitem b</a>
            <a href="#menu1sub1sub1" class="nav-link" data-bs-toggle="collapse" aria-expanded="false">Subitem c ▾</a>
            <div class="collapse ps-2" id="menu1sub1sub1" data-bs-parent="#menu1sub1sub1">
                <a href="#" class="nav-link">Subitem c.1</a>
                <a href="#" class="nav-link">Subitem c.2</a>
            </div>
        </div>
    </div>
    <a href="#" class="nav-link">Item 2</a>
    <a href="#" class="nav-link">Item 3</a>
    <a href="#" class="nav-link">Item 4</a>
</div>

Bootstrap 5 Vertical Sidebar