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Nested & Expandable Folders

Demo by Martin Ivanov utilizing hidden checkboxes and adjacent sibling combinators to set the "state" of each folder.

.css-treeview ul,
.css-treeview li
{
	padding: 0;
	margin: 0;
	list-style: none;
}

.css-treeview input
{
	position: absolute;
	opacity: 0;
}

.css-treeview
{
	font: normal 11px "Segoe UI", Arial, Sans-serif;
	-moz-user-select: none;
	-webkit-user-select: none;
	user-select: none;
}

.css-treeview a
{
	color: #00f;
	text-decoration: none;
}

.css-treeview a:hover
{
	text-decoration: underline;
}

.css-treeview input + label + ul
{
	margin: 0 0 0 22px;
}

.css-treeview input + label + ul
{
	display: none;
}

.css-treeview label,
.css-treeview label::before
{
	cursor: pointer;
}

.css-treeview input:disabled + label
{
	cursor: default;
	opacity: .6;
}

.css-treeview input:checked:not(:disabled) + label + ul
{
	display: block;
}

.css-treeview label,
.css-treeview label::before
{
	background: url("icons.png") no-repeat;
}

.css-treeview label,
.css-treeview a,
.css-treeview label::before
{
	display: inline-block;
	height: 16px;
	line-height: 16px;,
	vertical-align: middle;
}

.css-treeview label
{
	background-position: 18px 0;
}

.css-treeview label::before
{
	content: "";
	width: 16px;
	margin: 0 22px 0 0;
	vertical-align: middle;
	background-position: 0 -32px;
}

.css-treeview input:checked + label::before
{
	background-position: 0 -16px;
}

/* webkit adjacent element selector bugfix */
@media screen and (-webkit-min-device-pixel-ratio:0)
{
	.css-treeview 
	{
		-webkit-animation: webkit-adjacent-element-selector-bugfix infinite 1s;
	}
	
	@-webkit-keyframes webkit-adjacent-element-selector-bugfix 
	{
		from 
		{ 
			padding: 0;
		} 
		to 
		{ 
			padding: 0;
		}
	}
}
<div class="css-treeview">
	<ul>
		<li><input type="checkbox" id="item-0" /><label for="item-0">This Folder is Closed By Default</label>
			<ul>
				<li><input type="checkbox" id="item-0-0" /><label for="item-0-0">Ooops! A Nested Folder</label>
					<ul>
						<li><input type="checkbox" id="item-0-0-0" /><label for="item-0-0-0">Look Ma - No Hands!</label>
							<ul>
								<li><a href="./">First Nested Item</a></li>
								<li><a href="./">Second Nested Item</a></li>
								<li><a href="./">Third Nested Item</a></li>
								<li><a href="./">Fourth Nested Item</a></li>
							</ul>
						</li>
						<li><a href="./">Item 1</a></li>
						<li><a href="./">Item 2</a></li>
						<li><a href="./">Item 3</a></li>
					</ul>
				</li>
				<li><input type="checkbox" id="item-0-1" /><label for="item-0-1">Yet Another One</label>
					<ul>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
					</ul>
				</li>
				<li><input type="checkbox" id="item-0-2" disabled="disabled" /><label for="item-0-2">Disabled Nested Items</label>
					<ul>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
					</ul>
				</li>
				<li><a href="./">item</a></li>
				<li><a href="./">item</a></li>
				<li><a href="./">item</a></li>
				<li><a href="./">item</a></li>
			</ul>
		</li>
		<li><input type="checkbox" id="item-1" checked="checked" /><label for="item-1">This One is Open by Default...</label>
			<ul>
				<li><input type="checkbox" id="item-1-0" /><label for="item-1-0">And Contains More Nested Items...</label>
					<ul>
						<li><a href="./">Look Ma - No Hands</a></li>
						<li><a href="./">Another Item</a></li>
						<li><a href="./">And Yet Another</a></li>
					</ul>
				</li>
				<li><a href="./">Lorem</a></li>
				<li><a href="./">Ipsum</a></li>
				<li><a href="./">Dolor</a></li>
				<li><a href="./">Sit Amet</a></li>
			</ul>
		</li>
		<li><input type="checkbox" id="item-2" /><label for="item-2">Can You Believe...</label>
			<ul>
				<li><input type="checkbox" id="item-2-0" /><label for="item-2-0">That This Treeview...</label>
					<ul>
						<li><input type="checkbox" id="item-2-2-0" /><label for="item-2-2-0">Does Not Use Any JavaScript...</label>
							<ul>
								<li><a href="./">But Relies Only</a></li>
								<li><a href="./">On the Power</a></li>
								<li><a href="./">Of CSS3</a></li>
							</ul>
						</li>
						<li><a href="./">Item 1</a></li>
						<li><a href="./">Item 2</a></li>
						<li><a href="./">Item 3</a></li>
					</ul>
				</li>
				<li><input type="checkbox" id="item-2-1" /><label for="item-2-1">This is a Folder With...</label>
					<ul>
						<li><a href="./">Some Nested Items...</a></li>
						<li><a href="./">Some Nested Items...</a></li>
						<li><a href="./">Some Nested Items...</a></li>
						<li><a href="./">Some Nested Items...</a></li>
						<li><a href="./">Some Nested Items...</a></li>
					</ul>
				</li>
				<li><input type="checkbox" id="item-2-2" disabled="disabled" /><label for="item-2-2">Disabled Nested Items</label>
					<ul>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
						<li><a href="./">item</a></li>
					</ul>
				</li>
			</ul>
		</li>
	</ul>
</div>

Comments

  1. EJMD
    Permalink to comment#

    I’ve implemented this code into my website, but am having difficulties having it render properly in Safari. If the ‘items’ are too long in Firefox, the text word wraps perfectly. The same items, however, overlap in Safari and I can’t figure out how to fix that.

    Any help would be greatly appreciated.

    • Abhilash
      Permalink to comment#

      Try using word-wrap: break-word;
      in the items css wherever you want.

  2. Jessica Calhoun
    Permalink to comment#

    Trying to figure out how to search through this list (using Javascript probably) and only showing the folders and bottom most node(s) that the search returns. Any ideas here?

  3. Jeroenk
    Permalink to comment#

    “@-webkit-keyframes webkit-adjacent-element-selector-bugfix” breaks in firefox, all subsequent CSS won’t not be rendered.

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