Split an element containing TextNodes and elements using jQuery

Question

I need to split an HTML element based on a users selection using jQuery. In the following example square brackets indicate the selection:

Lor[em <a>ips]um <span>dolor</span></a>

should become

Lor [ em <a>ips</a> ] <a>um <span>dolor</span></a>

To do this I create a range, find the TextNodes containing the selection boundaries and split them using splitText(index). Next I check whether the parent element must also be split. If yes, I clone and empty them, move the second parts of the original elements into the clones and insert them after the original like so:

var tail = textNode.splitText( offset );
var $parent = $(textNode).parent();

if ($parent.is("span")) {
    var $tail = $parent.clone();
    $tail.contents().remove();
    $tail = $tail.append(tail).insertAfter($parent);

    if ($parent.parent().is("a")) {
        $tail = $parent.parent().clone();
        $tail.contents().remove();
        $tail = $tail.append($tail).insertAfter($parent.parent());
    }

    return $tail[0];
}
else if ($parent.is("a")) {
    var $tail = $parent.clone();
    $tail.contents().remove();
    $tail = $tail.append(tail).insertAfter($parent);

    return $tail[0];
}
return tail;

Problem is, though, tail only contains the second part of the TextNode. The following <span /> is not moved, so the HTML is messed up like so (selection is lost underway, but not important):

Lor em <a>ips <span>dolor</span></a> <a>um</a>

I also tried $(tail).nextAll() but it seems to return an empty set. Does anybody have an idea how I can achieve this? If anything is not clear, please ask for more detail.

EDIT: Like suggested I created the following http://jsfiddle.net/7PdLd/4/.

Answer 1

This seems to work:

Demo

function start () {
    var range = window.getSelection().getRangeAt(0);
    split(
        range.startContainer,
        range.startOffset,
        range.commonAncestorContainer,
        false
    );
    split(
        range.endContainer,
        range.endOffset,
        range.commonAncestorContainer,
        true
    );  
}
function split(node, offset, ancestor, backwards) {
    var clone;
    if(backwards) {
        clone = node;
        node = node.splitText(offset);
    }else{
        clone = node.splitText(offset);
    }
    if(node == ancestor) return;
    var parent;
    while((parent = node.parentNode) && parent != ancestor) {
        var parentClone = parent.cloneNode(false);
        appendUntil(parentClone, parent, node, !backwards);
        parentClone.insertBefore(clone, backwards ? null : parentClone.firstChild);
        node = parent;
        clone = parentClone;
    }
    insertAdjacent(ancestor, clone, node, backwards);
}
function appendUntil(target, parent, until, fromEnd) {
    var from, to, sibling;
    if(fromEnd) {
        from = until.nextSibling;
        to = null;
    } else {
        from = parent.firstChild;
        to = until;
    }
    while(from && from != to) {
        sibling = from.nextSibling;
        target.appendChild(from);
        from = sibling;
    }
}
function insertAdjacent(parent, newEl, refEl, before) {
    parent.insertBefore(newEl, before ? refEl : refEl.nextSibling);
}