How can I reorder/sort a NodeList in JavaScript?

Question

I have what I think should be a straightforward question; let me quickly explain:

In my JavaScript, food.xml is read in with:

getMenuXml.ope         


        

Answer 1

You can order the elements of the NodeList, if you convert them to an array first:

var foods = xmlDoc.getElementsByTagName("food");
var foodsArray = Array.prototype.slice.call(foods, 0);

Then you can use the sort method:

foodsArray.sort(function(a,b) {
    var aCat = a.getElementsByTagName("category")[0].childNodes[0].nodeValue;
    var bCat = b.getElementsByTagName("category")[0].childNodes[0].nodeValue;
    if (aCat > bCat) return 1;
    if (aCat < bCat) return -1;
    return 0;
});

This is highly dependent on your XML schema though - if, for example, you had foods which were in more than one category they would only be sorted by the first category in the code above.