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<!DOCTYPE HTML PUBLIC "html.dtd"><HTML><HEAD><TITLE>Presenting XML:Potential Applications of XML:EarthWeb Inc.-</TITLE><META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW"><SCRIPT><!--function displayWindow(url, width, height) { var Win = window.open(url,"displayWindow",'width=' + width +',height=' + height + ',resizable=1,scrollbars=yes');}//--></SCRIPT></HEAD><BODY BGCOLOR="#FFFFFF" VLINK="#DD0000" TEXT="#000000" LINK="#DD0000" ALINK="#FF0000"><TD WIDTH="540" VALIGN="TOP"><!-- <CENTER><TABLE><TR><TD><FORM METHOD="GET" ACTION="http://search.itknowledge.com/excite/cgi-bin/AT-foldocsearch.cgi"><INPUT NAME="search" SIZE="20" VALUE=""><BR><CENTER><INPUT NAME="searchButton" TYPE="submit" VALUE="Glossary Search"></CENTER><INPUT NAME="source" TYPE="hidden" VALUE="local" CHECKED> <INPUT NAME="bltext" TYPE="hidden" VALUE="Back to Search"><INPUT NAME="sp" TYPE="hidden" VALUE="sp"></FORM></TD><TD><IMG SRC="http://www.itknowledge.com/images/dotclear.gif" WIDTH="15" HEIGHT="1"></TD><TD><FORM METHOD="POST" ACTION="http://search.itknowledge.com/excite/cgi-bin/AT-subscriptionsearch.cgi"><INPUT NAME="search" SIZE="20" VALUE=""><BR><CENTER><INPUT NAME="searchButton" TYPE="submit" VALUE=" Book Search "></CENTER><INPUT NAME="source" TYPE="hidden" VALUE="local" CHECKED> <INPUT NAME="backlink" TYPE="hidden" VALUE="http://search.itknowledge.com:80/excite/AT-subscriptionquery.html"><INPUT NAME="bltext" TYPE="hidden" VALUE="Back to Search"><INPUT NAME="sp" TYPE="hidden" VALUE="sp"></FORM></TD></TR></TABLE></CENTER> --><!-- ISBN=1575213346 //--><!-- TITLE=Presenting XML//--><!-- AUTHOR=Richard Light//--><!-- PUBLISHER=Macmillan Computer Publishing//--><!-- IMPRINT=Sams//--><!-- CHAPTER=18 //--><!-- PAGES=0331-0356 //--><!-- UNASSIGNED1 //--><!-- UNASSIGNED2 //--><P><CENTER><A HREF="0350-0352.html">Previous</A> | <A HREF="../ewtoc.html">Table of Contents</A> | <A HREF="0356-0356.html">Next</A></CENTER></P><A NAME="PAGENUM-353"><P>Page 353</P></A><P>Before you hang up your traveling shoes, I should do one thing to makethis tour complete. Let's take a final glimpse at the crystal ball of the future andtry to anticipate some of the other applications that probably will beannounced over the next year or two. However, whereas someone once said that a weekin politics is a long time, a year in the Internet world is a century of normallife, and it is absolutely impossible to look very far ahead. So, to round outthis tour, let's make a quick examination of two applications that are not yetXML applications but probably will become them. Each of these applications isa classic example of two of the most important features that will make XMLa force to be reckoned with: HDML for handheld devices where aspecialized version of HTML is needed, and DDTP for support services where therichness of SGML is needed but without the complexity. XML will flourish inthese areas where SGML is too complex or simply too bulky, and where HTMLis too limited.</P><H4><A NAME="ch18_ 13">Handheld Devices</A></H4><P>When someone talks about "being on the Internet," a pictureautomatically springs to mind of the person sitting at a computer screen or perhaps atelevision screen. However, this image is slowly drifting away from reality asmore so-called handheld devices arrive on the market. Most of us have seensome kind of pocket agenda, and we've at least heard of these new pocket-sizedcomputers (Personal Digital Assistants, PDAs, to use the imaginative termthought up by their manufacturers). These are one type of handheld device, butthey are only the tip of the iceberg. Nokia already has one telephone on themarket that can send and receive e-mail, send and receive faxes, and even browseWeb pages. Although sophisticated machines such as Nokia's telephone sport astandard (if very small) keyboard, with the increasing adoption of Java (whichwas also meant to be able to run on domestic electronic appliances), itbecomes quite easy to imagine a fairly cheap and simple telephone (or even a pager)being used for surfing the Web.</P><P>Typical handheld devices can be characterized as having a small displayarea, limited input capabilities, a very limited bandwidth (the amount of datathey can handle at once), and limited computing resources (memory,processing power, and so on). (These devices don't really even need to be handheldas such. This could just as easily apply for voice-operated devices, orspecially adapted devices for the sight-impaired or the physically disabled.)</P><A NAME="PAGENUM-354"><P>Page 354</P></A><P>In the Handheld Device Markup Language (HDML) specification ofApril 1997 (version 2.0), the American company Unwired Planet puts forwarda proposal for a markup language that is similar in many ways to HTML butis much more attuned to this kind of device. The specification also proposesa supporting environment for interpreting this language, called auser agent.</P><P>The markup language itself is extremely simple. It uses 16 or so elementsand manages to describe the basic interaction between a user and a systemusing menus, menu choices, and tasks and pages (calledcards). It even manages to include basic text formatting (wrap, bold, centering, tabs, and so on). Mostof the work of displaying cards and acting on menu choices is done by theuser agent, which acts on a very extensive list of element attributes (which thespecification calls options).</P><P>If it was implemented, HDML would most certainly work and wouldprobably do a very good job. However, the specification, at least at themoment, does represent just one company's idea with seemingly little or no outsidesupport yet. Despite all the hard work and careful thought that has gone intoformulating the specification, it can surely be only a matter of time beforeHDML is rewritten as an XML DTD and the user agent is implemented as a Java applet.</P><H4><A NAME="ch18_ 14">Software Support</A></H4><P>Computer customer support (software and hardware) has experienced aphenomenal growth over the past few years. Today, it is almost unthinkable fora software company not to have a help desk, and computer companies havecome to appreciate this kind of customer support as a central part of theirbusiness that is essential to their survival. However, for many companies, theexpense, resource drain, and specialized skills demanded by a full-scale supportorganization are well beyond their capabilities, forcing them to contract outthese activities to specialist bureaus and agencies. On the other hand, the giantswho can afford to provide this kind of support have increasingly been made toface up to the fact that the majority of problems causing someone to seek thiskind of assistance are not restricted to their products alone, but are more oftenthe result of the difficulty of making several products from differentcompanies work together properly. Add to this the fact that computer products(both hardware and software) are becoming so complex that they are beyondthe possible understanding of any one individual, and then complicate matterseven further by accelerating the speed at which products are released onto themarket, and it is impossible for a support engineer to keep up. The result isan </P><A NAME="PAGENUM-355"><P>Page 355</P></A><P>environment in which the exchange of information is rapidly becomingessential to survival.</P><P>Since 1992, some of the major players faced with these problems(including some giants such as Microsoft, IBM, Novell, Lotus, Silicon Graphics,Hewlett-Packard, and Adobe) have been participating in an alliance called theCustomer Support Consortium. The main task of this alliance is to define a standard(called the Solution Exchange Standard) by which the member companies can"share customer knowledge and problem resolution information" by "capturing,reusing, and exchanging solutions to user problems."</P><P>Surely it will come as no surprise that an SGML DTD forms a central partof the Solution Exchange Standard, because nearly all the companies usedifferent software to manage support calls (some using simple text retrievaltools, and some using extremely sophisticated case-based reasoningtools). Companies can use an SGML DTD (called the Digital Document TransferProtocol, or DDTP) to identify the important information contained in incidentreports, diagnoses, and ultimate problem resolutions, plus any annotations, in away that can be made meaningful to customers, resellers, customer serviceproviders, hardware vendors, and software publishers via automated electronicdocument exchange.</P><P>At the end of 1996 and during the early part of 1997, the first softwarepackages supporting the standard started to appear on the market. Typical ofthis software is the SolutionPublisher, published by a company called Primusfrom Seattle, Washington. SolutionPublisher is a Web-based package thatsimulates a typical dialog between a user and a support engineer to collate a usableproblem description. This description is then matched against existing solutiondata, or if a solution cannot be found, a properly formed description is e-mailedto a human support engineer who can take things from there.</P><P>It is notable that Primus opted for HTML as its format forSolutionPublisher. Although it is possible for us to only guess why they chose not toimplement the full SGML DTD, the answers cannot be far from the many reasons Ihave already mentioned for SGML to not be adopted (such as its complexity,its bulk, and its cost). HTML will inevitably prove itself to be far too limited,far too rigid, and far too generic to survive for very long in this application.This is an application where XML can be expected to make its entry verysoon. SGML, on the other hand, is well up to the task, but the fact that usersupport </P><P><CENTER><A HREF="0350-0352.html">Previous</A> | <A HREF="../ewtoc.html">Table of Contents</A> | <A HREF="0356-0356.html">Next</A></CENTER></P></TD></TR></TABLE></BODY></HTML>⌨️ 快捷键说明
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