CODEWITHSUNDEEP
javascriptjsonxml
Cheng.Lee
Cheng.Lee

Reputation: 186

Why use the '@attributes' in the code when convert XML to JSON

I have seen many versions of the xml2json code using the '@attributes', the code is following,my question is why not just use obj[attribute.nodeName] = attribute.nodeValue?

// Changes XML to JSON
function xmlToJson(xml) {

    // Create the return object
    var obj = {};

    if (xml.nodeType == 1) { // element
        // do attributes
        if (xml.attributes.length > 0) {
        obj["@attributes"] = {};
            for (var j = 0; j < xml.attributes.length; j++) {
                var attribute = xml.attributes.item(j);
                obj["@attributes"][attribute.nodeName] = attribute.nodeValue;
    //why not just use obj[attribute.nodeName]  = attribute.nodeValue
            }
        }
    } else if (xml.nodeType == 3) { // text
        obj = xml.nodeValue;
    }

    // do children
    if (xml.hasChildNodes()) {
        for(var i = 0; i < xml.childNodes.length; i++) {
            var item = xml.childNodes.item(i);
            var nodeName = item.nodeName;
            if (typeof(obj[nodeName]) == "undefined") {
                obj[nodeName] = xmlToJson(item);
            } else {
                if (typeof(obj[nodeName].push) == "undefined") {
                    var old = obj[nodeName];
                    obj[nodeName] = [];
                    obj[nodeName].push(old);
                }
                obj[nodeName].push(xmlToJson(item));
            }
        }
    }
    return obj;
};

The link is here

Upvotes: 0

Views: 209

Answers (2)

&#193;lvaro Gonz&#225;lez
&#193;lvaro Gonz&#225;lez

Reputation: 146500

The XML format has a wider range of data structures than JSON. A give piece of info can be provided either as node:

<foo>33</foo>

... or as attribute:

<bar foo="33">

On the contrary, JSON provides no other way than object property:

{"foo": 33}

Given this limitation, writers of automated JSON to XML converters need a way to handle this situation and using an arbitrary prefix @ has become the de-facto standard.

Upvotes: 1

Cheng.Lee
Cheng.Lee

Reputation: 186

I knew it now. To distinguish the element attributes and child element attributes . When they equal each other , the trick works.

Like:<tag attr= "Val"> <attr subattr="sub Val "></attr> </tag>

Upvotes: 0

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