XML - Real thing, taken for granted
- By Jack Vaughan
Prognosticators and just plain curious folk often reflect on the next technology paradigm
shift. Application Development Trends recently took time out to do just such a class of
cogitating; the results will provide food for thought and, perhaps, some impetus for
controversy for some time to come.
The first article in this series is "Do tools matter?," which is featured in the February
edition of Application Development Trends magazine. There were more than a few interesting
sidelights we were unable to include in that issue, one of which we present here. It is, in
its own way, a consideration of the state of XML.
Why XML? Simple. It is the paradigm shift that is already happening. Yes, it has passed its fifth birthday; however, that means enough cogs and wheels are moving to make it useful. It
is also old enough to be under the radar of the proverbial hype-meisters (which may or may
not include those who tend to prefer the term "Web services" to "XML").
Simple? Maybe not. There is no simple meal when technology is the main course. XML is a
markup language, somewhat decipherable by mere mortals. But it must co-reside with a gaggle
of programmatic languages. In the process, long-running arguments about the value of
declarative languages and object-oriented (OO) methods again arise.
We asked Uche Ogbuji if XML is not a bigger paradigm shift than we imagined, and wondered
just how much XML is influencing the future course of development. "XML itself is not much
of a paradigm shift, but its effect on the future of development comes from the way in which
XML has brought together the thinking from many formerly separated worlds," he replied.
"Multiple disciplines of applications code development and database management, business
interchange, document management and more have been brought together by XML. These groups
have learned important lessons from each other in unprecedented ways under the umbrella of
XML. And I do believe that development will never be the same," he told us.
During our work on the "Do tools matter?" story, we asked a few industry luminaries for
their thoughts on the connections between XML and OO programming. Columnist Ogbuji had
recently written on the subject, contending that "the partnership between XML and OO will be
successful if XML finally gets OO programmers to accept declarative approaches to programming." This seemed to spur some controversy.
We asked BEA Systems' Adam Bosworth to respond to this contention. He did, saying, "I
disagree. It is always helpful to be able to describe things declaratively but it is never
sufficient. In the database programming world, for example, they started by trying to limit
the access model to a declarative one [SQL]. But soon enough, all three major vendors had to
invent procedural extensions [Transact SQL, PL/SQL and so on] to meet their customers' very
Uche was quick to note that he never said declarations were always sufficient. "I do believe that there is a role for imperative procedural code," he noted.
"My point is that in places where declarative code is naturally superior -- for example, in
the assertion of constraints -- mainstream object-oriented methods have been woefully
sluggish in encouraging developers toward better techniques," said Ogbuji, "and XML technologies are helping to catalyze a more positive trend.
"I'd also point out that Transact SQL, PL/SQL and the like are much more declarative in
nature than Java, C++ and the like," he concluded.
If you would like to receive a copy of the February ADT issue featuring "Do tools matter?,"
please drop us a post card at: State of Tools ADT-PRT, c/o ADT, 600 Worcester Road, Suite
301, Framingham, Mass. 01702, U.S.A. Please include your name and mailing address.
For more links to the extended version of ADT's "Do tools matter?," please go to http://www.adtmag.com/article.asp?id=8798
For other Programmers Report articles, please go to http://www.adtmag.com/article.asp?id=6265
For more XML news, go to ADT XML Page.
Jack Vaughan is former Editor-at-Large at Application Development Trends magazine.