Question

Actually I’ve parsed a website using htmlparser and I would like to find a specific value inside the parsed object, for example, a string “$199”, and keep tracking that element(by periodic parsing) to see the value is still “$199” or has changed.

And after some painful stupid searching using my eyes, I found the that string is located at somewhere like this:

price = handler.dom[3].children[3].children[3].children[5].children[1].
        children[3].children[3].children[5].children[0].children[0].raw;

So I’d like to know whether there are methods which are less painful? Thanks!

Answer 1

A tree based recursive search would probably be easiest to get the node you’re interested in.

I’ve not used htmlparser and the documentation seems a little thin, so this is just an example to get you started and is not tested:

function getElement(el,val) {
    if (el.children && el.children.length > 0) {
        for (var i = 0, l = el.children.length; i<l; i++) {
            var r = getElement(el.children[i],val);
            if (r) return r;
        }
    } else {
        if (el.raw == val) {
            return el;
        }
    }
    return null;
}

Call getElement(handler.dom[3],'$199') and it’ll go through all the children recursively until it finds an element without an children and then compares it’s raw value with ‘$199’. Note this is a straight comparison, you might want to swap this for a regexp or similar?