Another common data format for REST services is XML. If we have the option to choose a format, there are very small number of cases where JSON is not a better choice. XML is a better option if we need strict message validation using multiple namespaces and schemas, or for some reason, we use Extensible Stylesheet Language Transformations (XSTL). The biggest reason of all is the need to work with and support legacy environments that don't use JSON. Most of the modern server-side frameworks have a built-in support for content negotiation, meaning that depending on the client's request, they can serve up the same resource in different formats. In this recipe, we are going to create a simple XML server and use it from the client side.
For the server side, we will use Node.js with restify (http://mcavage.github.io/node-restify/) for the REST services, and xmlbuilder (https://github.com/oozcitak/xmlbuilder-js) for creating simple XML documents. To do this...