Using Perl With WDDX - The Big Picture (
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It's quite likely that you've never heard of WDDX before, so let me take a couple minutes to give you a quick overview.
WDXX, or Web Distributed Data eXchange, is a mechanism for representing and exchanging data structures (like strings and arrays) between different platforms and applications. It uses XML to create abstract representations of data, application-level components to convert the XML abstractions into native data structures, and standard Internet protocols like HTTP and FTP as the transport mechanism between applications.
Still confused, huh?
All right, let's try English for a change.
WDDX is simply a way of representing data - strings, numbers, arrays, arrays of arrays - in a manner that can be easily read and understood by any application. To illustrate this, consider the following PHP variable:
$str = "Robin Hood";
Here's how WDDX would represent this variable:
<wddxPacket version='1.0'>
<header/>
<data>
<string>Robin Hood</string>
</data>
</wddxPacket>
By creating an abstract representation of data, WDDX makes it possible to easily exchange data between different applications - even applications running on different platforms or written in different languages - so long as they all understand how to decode WDDX-encoded data. Applications which support WDDX will receive application-neutral WDDX data structures and convert them into an application-specific usable format. In other words, a Perl hash could be converted to a WDDX representation and sent to a Python script, which would decode it into a native Python list, or a PHP array could be sent to a JSP script, where it would be correctly recognized and handled.
By maintaining the integrity of data structures across different environments, writing platform-independent code becomes much easier. And, since WDDX data representations are nothing but regular XML, they can be transferred over any protocol that supports ASCII text - HTTP, email, FTP and so on. This makes WDDX both platform-neutral and portable - two attributes that have immediately endeared it to the developer community.
