xmlify

JavaScript/JSON/MongoDb/Mongoose to XML conversion

Usage no npm install needed!

<script type="module">
  import xmlify from 'https://cdn.skypack.dev/xmlify';
</script>

README

Convert JavaScript(/JSON) objects to XML

This package is particularly tailored to converting MongoDb / Mongoose documents to XML, for instance for APIs, RSS feeds, etc, which need to generate XML; though it can also be used for converting general JavaScript objects to XML.

There are various conventions in use for identifying how properties of JavaScript objects are to be converted into XML elements and attributes. For compatibility with MongoDb / Mongoose, this package uses a leading underscore ‘_’ to identify attributes. Otherwise, XML element names are taken from the JavaScript object property names. Objects and arrays can be nested arbitrarily deeply.

Summary

var xml = xmlify(jsObj, [root], [options]);

Installation

npm install xmlify

Usage

For use from eg Mongoose:

var xmlify = require('xmlify');
Blog.find(function(err, blogs) {
    if (err) return console.error(err);
    var xml = xmlify(blogs);
    console.log(xml);
}

With a MongoDb/Mongoose document:

var blog =
    {
        "_id": "54551d0b660186630b790db0",
        "title": "My Blog",
        "author": "Me",
        "body":   "Lots of interesting stuff to read",
        "comments": [
            { "body": "Nice blog", "date": "2014-11-02" },
            { "body": "Bit short", "date": "2014-11-03" }
        ],
        "date": "2014-11-01",
        "hidden": false,
        "meta": {
            "votes": 9,
            "favs": 99
        }
    }

then xmlify(blog) will generate:

<root id="54551d0b660186630b790db0">
    <title>My Blog</title>
    <author>Me</author>
    <body>Lots if interesting stuff to read</body>
    <comments>
        <comment>
            <body>Nice blog</body>
            <date>2014-11-02T00:00:00.000Z</date>
        </comment>
        <comment>
            <body>Bit short</body>
            <date>2014-11-03T00:00:00.000Z</date>
        </comment>
    </comments>
    <date>2014-11-01T00:00:00.000Z</date>
    <hidden>false</hidden>
    <meta>
        <votes>9</votes>
        <favs>99</favs>
    </meta>
</root>

By default, properties beginning with an underscore are converted to attributes, and pluralised arrays are wrapped in a singular enclosing element.

Options

The name of the root element can be supplied as a argument, as in

xml = xmlify(blog, 'blog');

The full range of options can be supplied in an options object:

  • attributeChar ['_']: character to interpret as indicating attributes (set to empty string for no attributes)
  • dateFormat ['ISO']: how dates should be formatted (ISO / SQL / JS)
  • xmlDeclaration [true]: whether to include an xml declaration
  • root ['root']: name of the generated XML root element
  • wrapArrays [true]: whether to wrap (plural) arrays in an enclosing element

So for example xmlify(blog, { root: 'blog', wrapArrays: false }) will generate

<blog id="54551d0b660186630b790db0">
    <title>My Blog</title>
    <author>Me</author>
    <body>Lots if interesting stuff to read</body>
    <comments>
        <body>Nice blog</body>
        <date>2014-11-02T00:00:00.000Z</date>
    </comments>
    <comments>
        <body>Bit short</body>
        <date>2014-11-03T00:00:00.000Z</date>
    </comments>
    <date>2014-11-01T00:00:00.000Z</date>
    <hidden>false</hidden>
    <meta>
        <votes>9</votes>
        <favs>99</favs>
    </meta>
</blog>

With a MongoDB / Mongoose collection:

var people =
    [
        {
            "_id": "544e73265730bb014972de3e",
            "name": { "first": "Walter", "last": "White" }
        },
        {
            "_id": "5454180c3e0dc88a784abc15",
            "name": { "first": "Jesse", "last": "Pinkman" }
        }
    ]

then xmlify(people, 'people') will generate

<people>
    <person id="544e73265730bb014972de3e">
        <name>
            <first>Walter</first>
            <last>White</last>
        </name>
    </person>
    <person id="5454180c3e0dc88a784abc15">
        <name>
            <first>Jesse</first>
            <last>Pinkman</last>
        </name>
    </person>
</people>

As XML can only have a single root tag, top-level arrays will always be wrapped by the XML root tag, irrespective of the wrappedArrays setting; though if wrappedArrays is set to false, no singular form will be used – xmlify(people, {root: 'people', wrappedArrays: false}) will generate:

<people>
    <people id="544e73265730bb014972de3e">
        <name>
            <first>Walter</first>
            <last>White</last>
        </name>
    </people>
    <people id="5454180c3e0dc88a784abc15">
        <name>
            <first>Jesse</first>
            <last>Pinkman</last>
        </name>
    </people>
</people>

Wrapped arrays will only operate on plural array names; with a source object such as:

var book =
    {
        _id: 123456789,
        title: "MongoDB: The Definitive Guide",
        author: [ "Kristina Chodorow", "Mike Dirolf" ],
        published_date: ISODate("2010-09-24"),
        pages: 216,
        language: "English"
    }

since the author array is singular, it will not get wrapped, so xmlify(book, {root: 'book', wrappedArrays: true}) will generate:

<book id="123456789">
    <title>MongoDB: The Definitive Guide</title>
    <author>Kristina Chodorow</author>
    <author>Mike Dirolf</author>
    <published_date>2010-09-24T00:00:00.000Z</published_date>
    <pages>216</pages>
    <language>English</language>
</book>

Xmlify will also work with simple (non-MongoDb) arrays, so with...

var stars =
    {
        "star": [
            "Itchy",
            "Scratchy"
        ]
    }

then xmlify(stars, 'stars') will generate:

<stars>
    <star>Itchy</star>
    <star>Scratchy</star>
</stars>

Using a property name of just underscore (or whatever attribute character option is chosen) will also fold the structure up – with:

var stars =
    {
        "star": [
            { "_": "Itchy" },
            { "_": "Scratchy" }
        ]
    }

then xmlify(stars, 'stars') will also generate:

<stars>
    <star>Itchy</star>
    <star>Scratchy</star>
</stars>

Nested (2-D) arrays cannot be converted, as there is no evident mapping to XML.