document.evaluate() on an HTML string

[spiderplant0]

Hi,
I was wondering if it's possible to capture a piece of HTML using XPath where the source is a sting rather than a document.

I know how to use xPath and document.evaluate() as I've used it before on actual web pages - I just dont understand how to run it on a string of HTML.

E.g. if I have this string:
var stg = "<div>The best-laid schemes o' <span>mice</span> an' men</div>";
I'd like to convert this string into something that I can run the document.evaluate() on so that I can find the contents of the SPAN element (without loading the string into a real browser page).

Thanks

[DaveyErwin]

<script type = "text/javascript">

var stg = "<div>The best-laid schemes o' <span>mice</span> an' men</div>";
if (window.DOMParser)
  {
  parser=new DOMParser();
  xml=parser.parseFromString(stg,"text/xml");}
else // Internet Explorer
  {
  xml=new ActiveXObject("Microsoft.XMLDOM");
  xml.async="false";
  xml.loadXML(stg);  }

path="/div/span";
// code for IE
if (window.ActiveXObject)
{
var nodes=xml.selectNodes(path);

for (i=0;i<nodes.length;i++)
  {
  document.write(nodes[i].childNodes[0].nodeValue);
  document.write("<br />");
  }
}
// code for Mozilla, Firefox, Opera, etc.
else if (document.implementation && document.implementation.createDocument)
{
var nodes=xml.evaluate(path, xml, null, XPathResult.ANY_TYPE,null);
var result=nodes.iterateNext();

while(result)
  {
  document.write(result.childNodes[0].nodeValue);
  document.write("<br />");
  result=nodes.iterateNext();
  }
}


</script>

[spiderplant0]

Thanks DaveyErwin. However I can only get it to work with valid XML/XHTML. If I use it on other HTML fragments (e.g. containing <br> rather than <br />) then it doesnt work. There doesnt seem to be a mime type for HTML for this function. (I'm using Firefox only).

I managed to find a solution for CSS selectors but it seems strange there is not an equivalent for xPath. See below..

    var stg = "<div>The best-laid<br> schemes o' <span>mice</span> an' men</div>";
    var newDiv = document.createElement("div");
    newDiv.innerHTML = stg;

    //this works
    console.log(newDiv.querySelectorAll("span")[0].textContent);

    //this doesnt work
    var recordNodes = newDiv.evaluate(
        ".//span",
        newDiv,
        null,
        XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,
        null );

     console.log(recordNodes.snapshotLength);

The mozilla function nsIScriptableUnescapeHTML.parseFragment() sounds like it might do the job but I cant get .evaluate() to work on it either (and the documentation is pretty slim).

[rnd me]

 var stg = "<div>The best-laid<br> schemes o' <br /><span>mice</span> an' men</div>";
    var newDiv = document.createElement("div");
    newDiv.innerHTML = stg;

      //this DOES work
    var recordNodes = document.evaluate(
        ".//span",
        newDiv,
        null,
        XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,
        null );

     console.log(recordNodes.snapshotLength);