xml2json.js

#!env node

const fs = require("fs");
const sax = require("./sax");

function parseXml(filename) {

    const parser = sax.parser(true);
    const doc = {};

    let current = doc;

    function string(type, text) {
        text = text.replace(/(^\s+|\s+$)/g, "");
        if (text) {
            const rank = current[`#${type}_rank`];
            current[`#${type}_${rank}`] = text;
            current[`#${type}_rank`] += 1;
        }
    }
    parser.ontext = string.bind(null, "text");
    parser.oncomment = string.bind(null, "comment");

    parser.onopencdata = function () {
        current[`#cdata_${current["#cdata_rank"]}`] = "";
    };

    parser.oncdata = function (cdata) {
        current[`#cdata_${current["#cdata_rank"]}`] += cdata;
    };

    parser.onclosecdata = function () {
        current["#cdata_rank"] += 1;
    };

    parser.onerror = function (error) {
        console.error(error.toString());
        parser.close();
    };

    parser.onopentag = function (node) {

        const newChild = {
            "#parent": current,
            "#text_rank": 0,
            "#comment_rank": 0,
            "#cdata_rank": 0
        };

        for (let a in node.attributes) {
            if (node.attributes.hasOwnProperty(a)) {
                newChild[`-${a}`] = node.attributes[a];
            }
        }

        if (current[node.name]) {

            if (current[node.name].constructor === Object) {
                current[node.name] = [ current[node.name] ];
            }

            current[node.name].push(newChild);

            if (!node.isSelfClosing) {
                current = newChild;
            }

        } else {
            current[node.name] = newChild;
        }

        current = newChild;
    };

    parser.onclosetag = function (name) {
        let target;
        current = current["#parent"];
        if (current[name].constructor === Array) {
            target = current[name][current[name].length - 1];
        } else {
            target = current[name];
        }
        delete target["#parent"];
        delete target["#text_rank"];
        delete target["#comment_rank"];
        delete target["#cdata_rank"];
    };

    parser.write(fs.readFileSync(filename).toString()).close();
    return doc;
}

console.log(JSON.stringify(parseXml(process.argv[2]), 0, "  "));