TweetFollow Us on Twitter

May 00 Online

Volume Number: 16 (2000)
Issue Number: 5
Column Tag: MacTech Online

May 00 Online

By Jeff Clites <online@mactech.com>

A few months ago, we briefly touched on the subject of XML, the biggest hype magnet since Java. A quick glance at any IT-related publication or website will give you a pretty good idea of the degree of interest there is in anything related to XML, and companies are churning out press releases about their plans to utilize XML faster than the press can cover them. XML isn't the Next Big Thing, it's the Current Big Thing. No matter where you stand on the hype-versus-substance issue, as a developer you'll need a working understanding of the technology to meet the demands of new standards and new modes of application interoperability. Beneath the static there is great potential in XML, and everyone will benefit from the attention it is drawing to issues surrounding communication and standardization. This month we'll cover a few of the resources you can turn to when working with this rapidly growing technology.

Documentation

Although there are many choices available, it is difficult to find the perfect printed reference; many of the obvious choices turn out not to be very good, and the field is evolving so rapidly that even the high-quality books quickly become out-of-date. For the moment, though, there are a couple of winners. The XML Pocket Reference, from O'Reilly and Associates, serves as both a beginner's introduction and a quick reference. For an extensive survey of current (and developing) technologies and APIs, try Professional XML from Wrox Press.

XML Pocket Reference
<http://www.oreilly.com/catalog/xmlpr/>

Professional XML
<http://www.wrox.com/Consumer/Store/Details.asp?ISBN=1861003110>

There is also no end to web-based coverage. An indispensable source is the XML FAQ, which covers a wide range of topics, and is well written. At the other end of the difficulty spectrum is the XML specification itself. Although you'll want to avoid it as long as possible, at some point you'll need to go back to the source to get the definitive word on something. It's a difficult read, but there is a cleverly-constructed annotated version available, which makes deciphering the formal language a bit easier. This latter reference is provided by XML.com, which is an excellent source of references and ongoing coverage of the industry, with timely articles on emerging technologies. Next, the XML Cover Pages are an exhaustive and neutral reference for all things XML (and SGML) related. Also of general interest is the original "mission statement" of the XML standard, which sets forth the design goals for its development. Finally, those planning on developing or working with XML parsers should take a look at the Lark parser, developed by Tim Bray, co-editor of the XML specification. It does not appear to be under active development, but it does provide an interesting case study in parser development in Java.

The XML FAQ
<http://www.ucc.ie/xml/>

The Annotated XML Specification
<http://www.xml.com/pub/axml/axmlintro.html>

XML.com
<http://www.xml.com/pub>

The XML Cover Pages
<http://www.oasis-open.org/cover/xml.html>

Design Principles for XML
<http://www.textuality.com/sgml-erb/dd-1996-0001.html>

An Introduction to XML Processing with Lark and Larval
<http://www.textuality.com/Lark/>

Programming XML

XML was designed to be easy to parse, and XML documents are often characterized as self-describing, but if you need to develop an XML-processing application you'll quickly find out that this is nonetheless not a trivial job. Fortunately, there are a number of parsers out there to help you with this task, and simple XML documents can in fact be created and parsed simply. One of the first XML parsers, and perhaps the most widely used, is James Clark's expat. It's a non-validating parser written in C, and recently an Objective C wrapper has been created for it, so it should be straightforward to use it from within Cocoa applications. (I believe that expat is also being used internally within Mac OS X, but it isn't clear what sort of API Apple will provide to access it.) Moving forward, it is likely that the Xerces parsers, which are part of the Apache XML project, will be widely used. They are validating parsers, and are available in Java, C++, and Perl. Much of their code originated from IBM's alphaWorks project, and IBM continues to provide its own versions, XML4J and XML4C for the Java and C++ versions respectively, which combine Xerces with their own Unicode classes, providing support for an expanded range of encodings. Apple is in fact using XML4J in their recently-released version 4.5 of WebObjects, and again it isn't clear to what extent the parser will be accessible from other parts of Apple's frameworks. Xerces-C contains a fair amount of code which must be customized when porting it to new platforms, but a classic Mac OS port has been developed, and a BSD version is in development which is likely to compile under Mac OS X. Also of note is the gnome-xml parser, which is under active development. It falls under the umbrella of the Linux Gnome project, but it is independent of the rest of Gnome and should be portable to other environments and platforms. (For example, it is known to work under Windows.) It is also a validating parser, but appears to be simpler than Xerces and may be worth a look if you need to access a validating parser from C and related languages. The gnome-xml web page also has links to several other articles to get you started, and in particular you should take a look at the article on IBM's developerWorks site.

expat - XML Parser Toolkit
<http://www.jclark.com/xml/expat.html>

Objective C wrapper for the expat XML Parser
<http://softrak.stepwise.com/Apps/WebObjects/Softrak.woa/1/wa/displayPackage?package=815&os=10>

The Apache XML Project
<http://xml.apache.org/>

IBM's XML Parser for Java (XML4J)
<http://www.alphaworks.ibm.com/tech/xml4j>

IBM's XML for C++ parser (XML4C)
<http://www.alphaworks.ibm.com/tech/xml4c>

The XML library for Gnome
<http://xmlsoft.org/>

Making application programming easy with GNOME libraries, Part 3
<http://www-4.ibm.com/software/developer/library/gnome3/>

If you're experimenting with XML for the first time, or you need to process XML in a web-related context, you should check out the numerous Perl modules available. A good place to start is the libxml-perl package. Of particular interest are the XML-Grove modules, which let you manipulate an XML document as a tree of objects and access various parts of it using a path-like syntax. This is analogous to the DOM and XPath APIs, and the grove interface will likely become obsolete after these have matured, but in the short term it provides a convenient and powerful approach to XML processing. There are a number of other APIs available for working with XML documents from Perl, including DOM-based and SAX-based parser APIs (the former allows you to access XML documents as a tree of objects, and the latter as a stream of events), as well as support for various approaches to XML querying. IBM has two excellent articles which are not to be missed; one gives a brief run-through of all of the XML-related Perl tools available, and the other gives a detailed tutorial on manipulating XML using Perl, including conversion of XML to HTML and XML-driven database access.

libxml-perl
<http://bitsko.slc.ut.us/>

Essential tools and libraries for using XML with Perl
<http://www-4.ibm.com/software/developer/library/perl-xml-toolkit/>

Manipulating XML documents with Perl and other scripting languages
<http://www-4.ibm.com/software/developer/library/xml-perl/>

When you grow weary of mucking around with the innards of the future web, cruise on over to the MacTech Online web pages at <www.mactech.com/online/>, and let you browser worry about the parsing for a while.

 
AAPL
$96.13
Apple Inc.
+0.53
MSFT
$42.86
Microsoft Corpora
-0.30
GOOG
$566.07
Google Inc.
-5.53

MacTech Search:
Community Search:

Software Updates via MacUpdate

Data Rescue 3.2.4 - Recover lost data on...
Data Rescue is a robust and reliable hard-drive recovery solution for your Mac. Recover lost or deleted files, mount corrupted drives, and more -- Data Rescue offers complete relief from crippling... Read more
Adobe Lightroom 5.6 - Import, develop, a...
Adobe Lightroom software helps you bring out the best in your photographs, whether you're perfecting one image, searching for ten, processing hundreds, or organizing thousands. Create incredible... Read more
OneNote 15.2 - Free digital notebook fro...
OneNote is your very own digital notebook. With OneNote, you can capture that flash of genius, that moment of inspiration, or that list of errands that’s too important to forget. Whether you’re at... Read more
iStat Menus 4.22 - Monitor your system r...
iStat Menus lets you monitor your system right from the menubar. Included are 8 menu extras that let you monitor every aspect of your system. Some features: CPU -- Monitor cpu usage. 7 display... Read more
Ember 1.8 - Versatile digital scrapbook....
Ember (formerly LittleSnapper) is your digital scrapbook of things that inspire you: websites, photos, apps or other things. Just drag in images that you want to keep, organize them into relevant... Read more
OmniPlan 2.3.6 - Robust project manageme...
With OmniPlan, you can create logical, manageable project plans with Gantt charts, schedules, summaries, milestones, and critical paths. Break down the tasks needed to make your project a success,... Read more
Command-C 1.1.1 - Clipboard sharing tool...
Command-C is a revolutionary app which makes easy to share your clipboard between iOS and OS X using your local WiFi network, even if the app is not currently opened. Copy anything (text, pictures,... Read more
Knock 1.1.7 - Unlock your Mac by knockin...
Knock is a faster, safer way to sign in. You keep your iPhone with you all the time. Now you can use it as a password. You never have to open the app -- just knock on your phone twice, even when it's... Read more
Mellel 3.3.6 - Powerful word processor w...
Mellel is the leading word processor for OS X and has been widely considered the industry standard since its inception. Mellel focuses on writers and scholars for technical writing and multilingual... Read more
LibreOffice 4.3.0.4 - Free Open Source o...
LibreOffice is an office suite (word processor, spreadsheet, presentations, drawing tool) compatible with other major office suites. The Document Foundation is coordinating development and... Read more

Latest Forum Discussions

See All

Bio Inc. is $0.99 for the Weekend, Recei...
Bio Inc. is $0.99 for the Weekend, Receives Small Update Posted by Ellis Spice on August 1st, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Happy 7th Birthday Readdle! Thank You fo...
Happy 7th Birthday Readdle! | Read more »
Sharknado: The Video Game Review
Sharknado: The Video Game Review By Lee Hamlet on August 1st, 2014 Our Rating: :: SHARKNA-DON'TUniversal App - Designed for iPhone and iPad Sharknado: The Video Game brings the craziness of the movies to iOS, though it quickly... | Read more »
Clima (Weather)
Clima 1.0 Device: iOS iPhone Category: Weather Price: $.99, Version: 1.0 (iTunes) Description: Clima show you all weather information, just beautifully simple. A series of color bars can tell you at a glance exactly current... | Read more »
Sticky Soccer Review
Sticky Soccer Review By Andrew Fisher on August 1st, 2014 Our Rating: :: STICK THIS GAMEUniversal App - Designed for iPhone and iPad Sticky Soccer puts too much emphasis on the ‘sticky’ and not enough on the ‘Soccer’ or ‘Fun’.   | Read more »
Graphics-less Apocalyptic Adventure A Da...
Graphics-less Apocalyptic Adventure A Dark Room Goes Free for a Limited Time Posted by Rob Rich on August 1st, 2014 [ permalink ] | Read more »
Fraud Tycoon Review
Fraud Tycoon Review By Rob Thomas on August 1st, 2014 Our Rating: :: UNHEALTHY CREDITUniversal App - Designed for iPhone and iPad Fraud Tycoon is a half-baked, messy, promotional tie-in that does their sponsor no favors whatsoever... | Read more »
Guardians of the Galaxy: The Universal W...
Guardians of the Galaxy: The Universal Weapon is on Sale for the Weekend Posted by Rob Rich on August 1st, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Mister Beam Review
Mister Beam Review By Jordan Minor on August 1st, 2014 Our Rating: :: ILLUMINATINGUniversal App - Designed for iPhone and iPad Mister Beam’s puzzles are great. But its platforming? Not so much.   | Read more »
Hook Some More Fun With MapHook’s New Up...
Hook Some More Fun With MapHook’s New Update Posted by Jessica Fisher on August 1st, 2014 [ permalink ] iPhone App - Designed for the iPhone, compatible with the iPad | Read more »

Price Scanner via MacPrices.net

13-inch MacBook Airs on sale for $100 off MSR...
B&H Photo has the new 2014 13″ MacBook Airs on sale $100 off MSRP. Shipping is free, and B&H charges NY sales tax only. They also include free copies of Parallels Desktop and LoJack for... Read more
16GB iPad Air on sale for $399, save $100
Best Buy is offering the 16GB WiFi iPad Air for $399.99 on their online store for a limited time. Their price is $100 off MSRP. Choose free shipping or free store pickup (if available). Price is for... Read more
All Over For Tablets Or Just A Maturing, Evol...
CNN’s David Goldman weighs in on tablet sector doom and gloom, asking rhetorically: “Is this the beginning of the end for the tablet?” Answering that, he contends that hysteria and panic are... Read more
Letterspace 1.0.1 – New Free iOS Text Editor...
Bangkok, Thailand based independent developer Sittipon Simasanti has released Letterspace, a new text editor for iPhone, iPad, and iPod touch devices. Letterspace is a note taking app with an... Read more
Save up to $130 on an iPad mini with Apple re...
The Apple Store has Certified Refurbished 2nd generation iPad minis with Retina Displays available for up to $130 off the cost of new models, starting at $339. Apple’s one-year warranty is included... Read more
iPad Cannibalization Threat “Overblown”
Seeking Alpha’s Kevin Greenhalgh observes that while many commentators think Apple’s forthcoming 5.5-inch panel iPhone 6 will cannibalize iPad sales, in his estimation, these concerns are being... Read more
Primate Labs Releases July 2014 MacBook Pro P...
Primate Labs’ John Poole has posted Geekbench 3 results for most of the new MacBook Pro models that Apple released on Tuesday. Poole observes that overall performance improvements for the new MacBook... Read more
Apple Re-Releases Bugfixed MacBook Air EFI Fi...
Apple has posted a bugfixed version EFI Firmware Update 2.9 a for MacBook Air (Mid 2011) models. The update addresses an issue where systems may take longer to wake from sleep than expected, and... Read more
Save $50 on the 2.5GHz Mac mini, plus free sh...
B&H Photo has the 2.5GHz Mac mini on sale for $549.99 including free shipping. That’s $50 off MSRP, and B&H will also include a free copy of Parallels Desktop software. NY sales tax only. Read more
Save up to $140 on an iPad Air with Apple ref...
Apple is offering Certified Refurbished iPad Airs for up to $140 off MSRP. Apple’s one-year warranty is included with each model, and shipping is free. Stock tends to come and go with some of these... Read more

Jobs Board

Position Opening at *Apple* - Apple (United...
**Job Summary** The Apple Store is a retail environment like no other - uniquely focused on delivering amazing customer experiences. As an Expert, you introduce people Read more
Position Opening at *Apple* - Apple (United...
**Job Summary** At the Apple Store, you connect business professionals and entrepreneurs with the tools they need in order to put Apple solutions to work in their Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Sr. Product Leader, *Apple* Store Apps - Ap...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
Sr Software Lead Engineer, *Apple* Online S...
Sr Software Lead Engineer, Apple Online Store Publishing Systems Keywords: Company: Apple Job Code: E3PCAK8MgYYkw Location (City or ZIP): Santa Clara Status: Full Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.