Jsonix

Jsonix (JSON interfaces for XML) is a JavaScript library which allows you to convert between XML and JSON structures.
With Jsonix you can parse XML into JSON (this process is called unmarshalling) or serialize JSON in XML form (this is called marshalling).
These conversions are based on declarative XML/JSON mappings which can be written manually or generated from an XML Schema.

Jsonix advantages:

Strongly structured
Type-safe
Bidirectional
(Optionally) XML Schema-driven

Example

Here's a working example for the purchase order schema (try it online in JSFiddle).

Generate mappings

java -jar node_modules/jsonix/lib/jsonix-schema-compiler-full.jar
  -d mappings -p PO purchaseorder.xsd

Generates mappings for the purchaseorder.xsd schema in the mappings\PO.js; mappings will be placed in the variable PO.

Parse XML into JS

// Include or require PO.js so that PO variable is available
// For instance, in node.js:
var PO = require('./mappings/PO').PO;

// First we construct a Jsonix context - a factory for unmarshaller (parser)
// and marshaller (serializer)
var context = new Jsonix.Context([PO]);

// Then we create a unmarshaller
var unmarshaller = context.createUnmarshaller();

// Unmarshal an object from the XML retrieved from the URL
unmarshaller.unmarshalURL('po.xml',
    // This callback function will be provided
    // with the result of the unmarshalling
    function (unmarshalled) {
        // Alice Smith
        console.log(unmarshalled.value.shipTo.name);
        // Baby Monitor
        console.log(unmarshalled.value.items.item[1].productName);
    });

You can also unmarshalString, unmarshalDocument and (under node.js) unmarshalFile.

Serialize JS as XML

// Create a marshaller
var marshaller = context.createMarshaller();

// Marshal a JavaScript Object as XML (DOM Document)
var doc = marshaller.marshalDocument({
    name: {
        localPart: "purchaseOrder"
    },
    value: {
        orderDate: { year: 1999, month: 10, day: 20 },
        shipTo: {
            country: "US",
            name: "Alice Smith",
            street: "123 Maple Street",
            city: "Mill Valley",
            state: "CA",
            zip: 90952
        },
        billTo: { /* ... */ },
        comment: 'Hurry, my lawn is going wild!',
        items: { /* ... */ }
    }
});

You can also marshalString.

Jsonix Features

Runs in almost any modern browser
Runs in Node.js
Runs with CommonJS modules, AMD modules as well as vanilla (globals, without any module loader)
Bidirectional (XML -> JS as well as JS -> XML)
Implements marshalling (serializing the JavaScript object into XML)
- Supports string data and DOM nodes as result
Implements unmarshalling (parsing a JavaScript object from XML)
- Supports string data, DOM nodes, URLs or files (with Node.js) as source
Driven by declarative XML/JS mappings which control how JavaScript object is converted into XML or vice versa
Mappings can be automatically generated based on the XML Schema
Strongly-structured - XML/object mappings describe structures of JavaScript objects
Strongly-typed - Conversion between string content on XML side and values on the JavaScript side is controlled by declared property types
Provides extensible type system
- Supports most XML Schema simple types (inlcuding QNames)
- Supports enumerations, list and union simple types
- Allows adding own simple types
- Supports complex types consisting of several properties
- Supports deriving complex types by extension
Provides advanced property system
- Value, attribute, element, element reference properties for string processing of XML content
- Any attribute, any element properties for "lax" processing for XML content