parse {a:{b:1}} to {a.b:1}

parseTreeObjToLine.js

var test = {
    id: 1,
    user: {
        role: [1, 2, 3, 4],
        userGroup: {
            id: 1
        },
        name: {
            first: "foo",
            last: "bar"
        }
    }
};

function parseTreeObjToLine(origin) {
    var o = {};
    return (function convert(obj, keyPath) {
        if (Object.prototype.toString.call(obj).slice(8, -1) !== 'Object') {
            o[keyPath] = obj;
            return;
        }

        Object.keys(obj).forEach(function(key) {
            keyPath = keyPath === '' || (~Object.keys(origin).indexOf(key) && keyPath.split('.').length) ? key : [keyPath, key].join('.');
            convert(obj[key], keyPath);
        });
        return o;
    })(origin, '');
}

console.log(parseTreeObjToLine(test));