Highlight text in HTML using Javascript ExecCommand

Ref:
http://www.quirksmode.org/dom/execCommand.html
http://www.quirksmode.org/dom/execCommand/

http://stackoverflow.com/questions/8429290/any-alternative-to-using-execcommand-for-highlighting-html-in-ios-ebook-reader

<script>
function makeEditableAndHighlight(colour) {
    var range, sel = window.getSelection();
    if (sel.rangeCount && sel.getRangeAt) {
        range = sel.getRangeAt(0);
    }
    document.designMode = "on";
    if (range) {
        sel.removeAllRanges();
        sel.addRange(range);
    }
    

// Use HiliteColor since some browsers apply BackColor to the whole block
    if (!document.execCommand("HiliteColor", false, colour)) {
        document.execCommand("BackColor", false, colour);
    }
    document.designMode = "off";
}

function highlight(colour) {
    var range, sel;
    if (window.getSelection) {
        // IE9 and non-IE
        try {
            if (!document.execCommand("BackColor", false, colour)) {
                makeEditableAndHighlight(colour);
            }
        } catch (ex) {
            makeEditableAndHighlight(colour)
        }
    } else if (document.selection && document.selection.createRange) {
        // IE <= 8 case
        range = document.selection.createRange();
        range.execCommand("BackColor", false, colour);
    }
}
var doHighlight = function(color){
    highlight(color);
};
</script>

<p> some text here, you can select and click the highlight button to highlight selection </p>


<button onclick="javascript:doHighlight('yellow');">Yellow Highlight</button>

Replace document.execCommand("HiliteColor", false, colour) with styleRange(range, style) will make it faster:

<script>
function makeEditableAndHighlight(colour) {
    var range, sel = window.getSelection();
    if (sel.rangeCount && sel.getRangeAt) {
        range = sel.getRangeAt(0);
    }
    document.designMode = "on";
    if (range) {
        sel.removeAllRanges();
        sel.addRange(range);
    }
    
    /* ***********REPLACE ************/
    /*
    // Use HiliteColor since some browsers apply BackColor to the whole block
    if (!document.execCommand("HiliteColor", false, colour)) {
        document.execCommand("BackColor", false, colour);
    }
    */
    styleRange(range, "background-color:yellow; color:red;");
    document.designMode = "off";
}

function styleRange(range, style) // the style is a string of css styles. eg."background-color:darkblue; color:blue;"{        // Get the start and end nodes and split them to give new start and end nodes with only text that falls inside the range.    var startNode = range.startContainer.splitText(range.startOffset);    var endNode = range.endContainer.splitText(range.endOffset).previousSibling;
    // Adjust the range to contain the new start and end nodes    // The offsets are not really important anymore but might as well set them correctly    range.setStart(startNode,0);    range.setEnd(endNode,endNode.length);
    // Get an array of all text nodes within the range    var nodes = getNodesInRange(range);
    // Place span tags with style around each textnode    for (i = 0; i < nodes.length; i++)    {        var span = document.createElement('span');        span.setAttribute("style", style);        span.appendChild( document.createTextNode(nodes[i].nodeValue));        nodes[i].parentNode.replaceChild( span, nodes[i] );    }}
function getNodesInRange(range){    var start = range.startContainer;    var end = range.endContainer;    var commonAncestor = range.commonAncestorContainer;    var nodes = [];    var node;
    // walk parent nodes from start to common ancestor    for (node = start.parentNode; node; node = node.parentNode)    {        if (node.nodeType == 3) //modified to only add text nodes to the array            nodes.push(node);        if (node == commonAncestor)            break;    }    nodes.reverse();
    // walk children and siblings from start until end is found    for (node = start; node; node = getNextNode(node))    {        if (node.nodeType == 3) //modified to only add text nodes to the array            nodes.push(node);        if (node == end)            break;    }
    return nodes;}

function getNextNode(node, end){    if (node.firstChild)        return node.firstChild;    while (node)    {        if (node.nextSibling)            return node.nextSibling;        node = node.parentNode;    }}