A universal canvas requires a
universal way to represent data. Other solutions are conceivable, but
let's accept for now that
XML is a reasonable one, and that it's here to stay. How does XML
become Play-doh? The first answer, for me, was Perl with
its XML::Parser module. Then came XSLT (XSL Transformation), which
traded away procedural idioms to gain declarative transformational
power. Then came Python with its libxml/libxslt modules, which married
the procedural and declarative styles in a highly interactive
way. That's been my weapon of choice lately, but now there's a new
contender: E4X (ECMAScript for XML).
With E4X, XML becomes a native programming-language data type. The language is ECMAScript, popularly known as JavaScript (in
browsers) and ActionScript (in Macromedia's Flash player). I first heard about E4X from Adam Bosworth, who used it to manage the intelligent browser cache that was
part of his Alchemy project. (Now that Bosworth has moved from BEA to Google, by the way, the future of that nascent open source project is uncertain.)
Meanwhile, the first generally
available implementation of E4X has been built into the latest version
of Rhino, the Mozilla
project's Java-based JavaScript engine. It was demonstrated to me
recently by John Schneider, the chief technologist at AgileDelta
and lead editor of the E4X specification. I was immediately inspired to
try it out, and you can see some
sample experiments on my Weblog. I'll spare you the geeky details, but here's the gist: More than any other technology, E4X makes XML data feel like Play-doh
in the hands of a programmer. That's not the endgame -- I won't be satisfied until users can reach into their XML data and
make new things with it -- but it's a step in the right direction. [Full story at InfoWorld.com]
So there's plenty of interest in the idea. As I mentioned the other day, I hope it gets expressed in ways that anticipate a common approach to serializing XML objects, and connecting to XML-aware databases.
NEWS 
