How to get an object from an XML document?

Question

When parsing documents using the excellent libxmljs library in Node.js, I stumbled across a case where a lot of nested elements were found, and the only thing I had to do was create a JS object from it.

Here is what the code looks like :

if (node.type() == 'element') {
        switch(node.name()) {
          case 'element1': {
              myObject.element1 = {}
              for (var i = 0; i < node.childNodes().length; i++) {
                  if(node.type() == 'element') {
                      switch(node.name()) {
                          case 'element2': {
                              myObject.element1.element2 = node.text()
                              ...
}}}}}}}} 
/* didn't count the number of closing brackets, but you get the idea ^_^ */

Is there a faster or built-in way to do such things, create an object from an XML string (or part of it) using libxmlJS ?

Note that, if it helps, the parsed XML must be validated against a XTD schema (which can really easily be done using this library)

Thanks

Answer 1

Here is some non-working code that can be found on this article :

function XML2jsobj(node) {

    var data = {};

    // append a value
    function Add(name, value) {
        if (data[name]) {
            if (data[name].constructor != Array) {
                data[name] = [data[name]];
            }
            data[name][data[name].length] = value;
        }
        else {
            data[name] = value;
        }
    };

    // element attributes
    var c, cn;
    for (c = 0; cn = node.attributes[c]; c++) {
        Add(cn.name, cn.value);
    }

    // child elements
    for (c = 0; cn = node.childNodes[c]; c++) {
        if (cn.nodeType == 1) {
            if (cn.childNodes.length == 1 && cn.firstChild.nodeType == 3) {
                // text value
                Add(cn.nodeName, cn.firstChild.nodeValue);
            }
            else {
                // sub-object
                Add(cn.nodeName, XML2jsobj(cn));
            }
        }
    }

    return data;

}

From that code, I could build something that seems to work with the latest libxmljs release, here it is :

function XML2jsobj(node) {
    var data = {};

    // append a value
    function Add(name, value) {
        if (data[name]) {
            if (data[name].constructor != Array) {
                data[name] = [data[name]];
            }
            data[name][data[name].length] = value;
        }
        else {
            data[name] = value;
        }
    };

    for (var c = 0; c < node.attrs().length; c++) {
        var cn = node.attrs()[c];
        Add(cn.name, cn.value);
    }

    // child elements
    for (var c = 0; c < node.childNodes().length; c++) {
        var cn = node.childNodes()[c];
        if (cn.type() == 'element') {
            if (cn.childNodes().length == 1 && cn.childNodes()[0].type() == 'text') {
                // text value
                Add(cn.name(), cn.childNodes()[0].text());
            }
            else {
                // sub-object
                Add(cn.name(), XML2jsobj(cn));
            }
        }
    }

    return data;
}

I hope this will have helped someone.