Trees in Twitter Bootstrap

Building on Vitaliy's CSS and Mehmet's jQuery, I changed the a tags to span tags and incorporated some Glyphicons and badging into my take on a Bootstrap tree widget.

Example:

For extra credit, I've created a GitHub project to host the jQuery and LESS code that goes into adding this tree component to Bootstrap. Please see the project documentation at http://jhfrench.github.io/bootstrap-tree/docs/example.html.

Alternately, here is the LESS source to generate that CSS (the JS can be picked up from the jsFiddle):

@import "../../../external/bootstrap/less/bootstrap.less"; /* substitute your path to the bootstrap.less file */
@import "../../../external/bootstrap/less/responsive.less"; /* optional; substitute your path to the responsive.less file */

/* collapsable tree */
.tree {
    .border-radius(@baseBorderRadius);
    .box-shadow(inset 0 1px 1px rgba(0,0,0,.05));
    background-color: lighten(@grayLighter, 5%);
    border: 1px solid @grayLight;
    margin-bottom: 10px;
    max-height: 300px;
    min-height: 20px;
    overflow-y: auto;
    padding: 19px;
    a {
        display: block;
        overflow: hidden;
        text-overflow: ellipsis;
        width: 90%;
    }
    li {
        list-style-type: none;
        margin: 0px 0;
        padding: 4px 0px 0px 2px;
        position: relative;
        &::before, &::after {
            content: '';
            left: -20px;
            position: absolute;
            right: auto;
        }
        &::before {
            border-left: 1px solid @grayLight;
            bottom: 50px;
            height: 100%;
            top: 0;
            width: 1px;
        }
        &::after {
            border-top: 1px solid @grayLight;
            height: 20px;
            top: 13px;
            width: 23px;
        }
        span {
            -moz-border-radius: 5px;
            -webkit-border-radius: 5px;
            border: 1px solid @grayLight;
            border-radius: 5px;
            display: inline-block;
            line-height: 14px;
            padding: 2px 4px;
            text-decoration: none;
        }
        &.parent_li > span {
            cursor: pointer;
            /*Time for some hover effects*/
            &:hover, &:hover+ul li span {
                background: @grayLighter;
                border: 1px solid @gray;
                color: #000;
            }
        }
        /*Remove connectors after last child*/
        &:last-child::before {
            height: 30px;
        }
    }
    /*Remove connectors before root*/
    > ul > li::before, > ul > li::after {
        border: 0;
    }
}

If someone wants vertical version of the treeview from Harsh's answer, you can save some time:

http://jsfiddle.net/Fh47n/

.tree li {
    margin: 0px 0;

    list-style-type: none;
    position: relative;
    padding: 20px 5px 0px 5px;
}

.tree li::before{
    content: '';
    position: absolute; 
    top: 0;
    width: 1px; 
    height: 100%;
    right: auto; 
    left: -20px;
    border-left: 1px solid #ccc;
    bottom: 50px;
}
.tree li::after{
    content: '';
    position: absolute; 
    top: 30px; 
    width: 25px; 
    height: 20px;
    right: auto; 
    left: -20px;
    border-top: 1px solid #ccc;
}
.tree li a{
    display: inline-block;
    border: 1px solid #ccc;
    padding: 5px 10px;
    text-decoration: none;
    color: #666;
    font-family: arial, verdana, tahoma;
    font-size: 11px;
    border-radius: 5px;
    -webkit-border-radius: 5px;
    -moz-border-radius: 5px;
}

/*Remove connectors before root*/
.tree > ul > li::before, .tree > ul > li::after{
    border: 0;
}
/*Remove connectors after last child*/
.tree li:last-child::before{ 
      height: 30px;
}

/*Time for some hover effects*/
/*We will apply the hover effect the the lineage of the element also*/
.tree li a:hover, .tree li a:hover+ul li a {
    background: #c8e4f8; color: #000; border: 1px solid #94a0b4;
}
/*Connector styles on hover*/
.tree li a:hover+ul li::after, 
.tree li a:hover+ul li::before, 
.tree li a:hover+ul::before, 
.tree li a:hover+ul ul::before{
    border-color:  #94a0b4;
}

Can you believe that the treeview on the image below does not use any JavaScript, but relies only on CSS3? Check out this CSS3 TreeView, which is good with Twitter BootStrap:

You can get more info about this here http://acidmartin.wordpress.com/2011/09/26/css3-treevew-no-javascript/.