I've just posted an introductory discusion on JavaScript Object Notation (JSON). What's itneresting about it is it provides away to get around the cross-domain issues you get when you try to access web services using Ajax. Yahoo's now outputting JSON in a ridiculously easy way, so this is worth checking out.
I've discovered that I'm generally cranky when I post to InformIT. My take on a one-click aggregation solution is no exception.
Almost a year ago, I wrote about what I want in an RSS aggregator, and now, as I actually write one in C++ (see, I told you I was doing it) I've gone back and found that all of those requests are still valid. And I still don't see anybody doing all of it.
Adam Kinney liked the XAML article. Thanks, Adam! Must have gotten it right, because Adam works at Xamlon. :)
Now featured on developerWorks: Using the Generic Log Adapter with the Log and Trace Analyzer
The GLA and LTA are Eclipse-based tools that enable logs to be parsed for occurrences of pre-defined events, relate those events to situations, and recommend actions based on information in a knowledge base. This tutorial is of particular interest to developers and administrators of applications with dependencies on multiple servers, such as DB2, Apache, and WebSphere. The key lesson imparted here is how to use the GLA to create your own adapter for custom application logs. Additionally, the tutorial introduces the underlying elements of the log adapter process. These low-level enablers of autonomic computing systems are an important contributor to the creation of more autonomic computing systems. This tutorial takes you through an example of how high-level open standards, such as the Common Base Event description, can be incorporated into development and administration functions at a practical level.
Now on developerWorks: Understand the Autonomic Management Engine
"The idea of an autonomic computing system is attractive -- who wouldn't want a system that knows what to look for, and what to do if it finds it? But, building one from scratch is too much of an undertaking for most shops. Fortunately, the Autonomic Management Engine simplifies the process. This tutorial explains how AME works and shows you how to embed it into one of your own applications."
This is actually pretty cool. Well, I think so, anyway. :)
Ever heard of XUL? It's a new way of building web applications in Mozilla (and the newer versions of Netscape). Kind of like a "super" form, with all kinds of interactivity available. I still haven't had time to fool around with it, despite a brief interlude when it looked like I might have to write a tutorial on it, but check out the Mozilla Amazon Browser, a very cool look at what you can do with it. This link is via Jono Bacon's Mozilla and the potential for interaction, which is itself an interesting read, considering the idea of porting applications such as OpenOffice to XUL.
Cool.
XInclude, designed to make it easier to include part of one XMl document into another, has been a neglected specification for a long time. Now Bob DuCharme gives a good example of how it can be useful with Transclude with XInclude (and XPointer!). It still doesn't address the security issues, but OK, there you are.
Now in the XML Reference Guide over at : DOM and PHP
PHP has support for XML built in, but as far as production code, it's limited to SAX. You can install the DomDocument module, but you do, of course, have to have access to the actual server in order to use it. Fortunately, for those of you who, like me, use an external web server and don't have that kind of control, there's a simple way to get Document Object Model functionality. ...
Now on InformIT in the XML Reference Guide: Java in XSLT: Extension Functions
Using XSLT to transform XML into another form has a lot of advantages, not the least of which is flexibility. When you want to change the output, you don't have to go back to the code, you simply have to change the XSLT style sheet. But it's easy to mistake this simplicity for shallowness. XSLT can enable you to do much more than simply reformatting text.
John wrote:
> Hi Nicolas,
> I wonder if you could answer a problem I am having
> processing an XML file with a Java application. The
> XML file is ejb-jar.xml. There is a line referencing a
> DTD e.g.
> Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN"
> "http://java.sun.com/dtd/ejb-jar_2_1.dtd">.
> However, when my internet connection or java.sun.com
> is down, I am unable to retrieve the dtd and thus get
> a FileNotFoundException. I have tried saving the dtd
> in the java classpath with no success. The error
> occurs when I call: builder.parse(new
> File("ejb-jar.xml"));
>
> Any suggestions or comments would be appreciated.
> thanks.../john
Hi, John!
The trouble is that the parser is trying to retrieve the file
from http://java.sun.com/dtd/ejb-jar_2_1.dtd. You can solve
this problem by saving a local copy to the same directory as
the XML file and changing the DOCTYPE declaration to read
"-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN"
"ejb-jar_2_1.dtd">
I hope that helps!
---- Nick
In the InformIT XML Reference Guide: DOM and Perl
Perl was originally designed as a lnaguage for sorting through text, so it's not surprising that it is a good fit for XML. In fact, there are multiple ways to handle XML using Perl, so in this section we're going to look at manipulating DOM "objects" using the Perl XML::DOM module, available on CPAN. ...
Now updated on developerWorks: Integrating applications with Web services using WebSphere Studio V5.1.1: "This tutorial looks at making your application Web-services ready using WebSphere Studio's tools to wrap an existing application as a Web service, announce it using a UDDI directory, and to discover and use Web services within your applications. It also looks at how to deploy your application to a WebSphere Application Server."
In the InformIT XML Reference Guide: .NET and XMLReader
In the world of XML, it's natural to think of XML in terms of two contexts: DOM and SAX. DOM is flexible, in that it provides the ability to navigate around the document tree and make changes, but SAX is fast, in that it doesn't load the entire document into memory, looking instead at just a single node at a time in a forward-only, read-only manner. ...
Well, I've finally gotten around to writing about .NET, with a section on DOM and .NET at the InformIT XML Reference Guide. It explains how to create an application in .NET that traverses the Document Object Model of an XML Document object. It uses Visual Basic .NET, but the concepts are the same for C#.
Well, I've finally taken the gloves off and posted a snarky posting to InformIT, What? You mean you can read an XML file from another application?
The scoop? Microsoft is now trying to patent methods for reading an XML file produced by another application as a way to keep companies from building competing products that read a Word file.
But I've dropped my usual objective demeanor on this one. Let's see if anybody notices or -- gasp -- comments on the InformIT blog. I hope so.
OK, the first posting from the list is up. News from the world of DSDL incorporates items number 2, 3, 4 and 5 and talks about Document Schema Definition Languages, which aims to make it easier to validate documents that have data from more than one namespace, such as a SOAP envelope or an XHTML document with SVG embedded within it.
I understand that there are people who read all of the blogs on their blogroll every day, or at least, every few days. And they even find time to comment on them. I want to know who these people are and how they manage to make a living.
I have, in essence, three blogs that I am supposed to be updating on a regular basis. I'm supposed to do at least three blogs a week for the XML Reference Guide, I've got this one, and I've got The Vanguard Science Fiction Report, which has been fallow so long I'm embarrassed to admit that it's mine. So today, now that the weeks of emergency room visits and surgeries in the family have settled down into the normal level of chaos, I sat down and went through my blogroll for potential posting material.
I thought it might be a little educational to document the "flow" of my surfing, and how it eventually gets turned into actual postings, so here is the list of the "first cut". These are postings that may eventually wind up on one of my three blogs:
And some XML tools mentioned on Cafe Con Leche:
Even I can't believe how long the list is.
As you can see, it's a rather eclectic group, but it also shows the pattern of how I surf. (Note that I didn't even touch Op-Ed News today, because I know I have enough material for this blog, which is the only place it belongs, or the W3C because I've adopted a "monthly" schedule for them on InformIT.)
Over the next week or so, you can see what makes the cut and what doesn't, and what leads to other things.
So I posted over at InformIT about How to survive the changes to IE.
So what are the actual changes? Well, it turns out to not be as bad as originally thought. The patent covers the automatic loading of an application that resides on a remote server, so a page either needs to avoid automatically loading the application or loading it from a remote server. For the former, IE will pop up a window asking the user to click a button to load the Active X control. For the latter, Microsoft has guidance on embedding the data directly into the page so that it doesn't actually have to be loaded remotely. They also provide a look at using JavaScript to create the object tag in such a way that the patent isn't violated, but you don't have to jump through a hundred hoops to keep the dialogue box from coming up.
What I want to know is: how does this embedding affect security? Is it possible that slimebags are currently embedding the code in the page to avoid warnings about downloading controls?
At the end of December, I wrote about The evils of escaped markup as seen by Normal Walsh. It was a well-though-out piece about why he doesn't like that people are using CDATA sections to escape potentially non-well-formed content, particularly in data feeds.
But the interesting thing to me is that I'd actually already written about this particular topic -- and in fact, this particular piece of Norman's -- last summer.
So far, nobody has noticed. Or if they have, they haven't commented.
I'm considering thinking of something completely ridiculous and controversial to say just to see if anybody notices. Suggestions welcome.
I just commented over at InformIT about the changes to IT. Now that I see what they actually are, I can see that it's frankly not that big a deal. Or is it? The idea is that the patent covers the launching of a remote application, so instead, the plan is to get people to either create a script that creates the object tag or to embed the ActiveX control into the page as Base64.
So now I'm thinking: what kind of security concerns are engendered by the fact that the code is embedded on the page? Because they're not being downloaded, hwo will the user be able to filter out what they want to enable to run and what they don't?
In the InformIT XML Reference Guide: DOM and .NET
With XML so fundamental in Microsoft's .NET framework, it should come as no surprise that the ability to manipulate an XML document is built right into the system. In fact, although DOM Level 2.0 doesn't include a standard way to create or save a document, .NET makes it easy. In this section, we'll get a feel for how these manipulations work by using Visual Basic .NET to load a simple document, make some changes to it, and then save it back out to a file. (We'll be running directly from the command line, so if you're not familiar with GUI programming, don't worry.) ...
So I was thinking over at InformIT about standards bodies and their relevance, but my really big question is this: what would happen if we all decided NOT to use an accepted standard, and used something else instead?
I mean, seriously. What if a group of scientists decided not to use the "accepted" names for the elements, or renamed the planets or something? I mean, there's no law about it, right?
In my research about cargo cults (more in a few minutes) I came across an interesting navigational element on the Apologetics Index. The menu stays as a tab on the left and travels when you scroll (though it's a tad distracting to start with) and pops out when you roll over it. My first thought is that it would be an accessibility nightmare, but now I'm thinking that if you did it right, you could make it work for those both with and without scripting support -- if the script doesn't work, the navigation simply appears -- and for those with traditional and non-traditional browsers.
Hm.
I commented more extensively on Clay Shirky's The Semantic Web, Syllogism, and Worldview over on InformIT, but I have one more point to question.
Clay's talking about syllogisms, and uses this one as an example of why thy don't work:
"Consider the following assertions:
- Count Dracula is a Vampire
- Count Dracula lives in Transylvania
- Transylvania is a region of Romania
- Vampires are not real
You can draw only one non-clashing conclusion from such a set of assertions -- Romania isn't real."
Excuse me? I think the main problem is that he's mis-understanding the difference between
A are B
and
All A are B
I commented more over at InformIT.
Now on developerWorks: DOM NodeFilters and XML data binding: Using a DOM NodeFilter lets you control the contents of a set of XML data without touching the base application, but the NodeFilter itself is still a class, and needs to be recompiled in order to make any non-trivial changes. This tutorial explains how to build a system that enables a user to control both the criteria for a report and the structure of that criteria simply by providing XML input, either through a file or through a web service, using XML Data Binding.
Apparently the Batik SVG package from Apache has a built-in rasterizer to convert SVG images to JPGs, so you don't have to rely on the user having an SVG viewer installed. Cool! Benoit Marchal explains how it works.
Now on developerWorks: Grab headlines from a remote RSS file: This article shows you how to retrieve syndicated content and convert it into headlines for your site. Since no official format for such feeds exists, aggregators are often faced with the difficulty of supporting multiple formats, so Nick also explains how to use XSL transformations to more easily deal with multiple syndication file formats. (This was actually published in September.)
I am pretty darn proud of XML Primer Plus. I knew the subject well, and I worked hard on it. I also feel good about the fact that it covers not only Java, but also C++, VB.NET, Perl, and PHP, thanks to the help of some additional writers. The reviews have all been good, and even the four star review on Amazon says that the only reason he didn't give me five stars is because he feels that that levels should be reserved for "recognized experts in the field," which I clearly am not.
But sales have been, frankly, disappointing. I was feeling really bad about it -- until I found out that The XML Book Business is in the toilet. With very few exceptions (and frankly I can't think of any), nobody's XML books are selling.
So tell me, are you buying XML books? Why or why not?
Now on IBM developerWorks: Understanding SAX (Tutorial) -- This tutorial examines the use of the Simple API for XML version 2.0.x, or SAX 2.0.x. It is aimed at developers who have an understanding of XML and wish to learn this lightweight, event-based API for working with XML data. It assumes that you are familiar with concepts such as well-formedness and the tag-like nature of an XML document. In this tutorial, you will learn how to use SAX to retreive, manipulate, and output XML data.
Now in IBM developerWorks: Understanding DOM (Tutorial) -- Even before there was XML, there was the Document Object Model, or DOM. It allows a developer to refer to, retrieve, and change items within an XML structure, and is essential to working with XML. In this tutorial, you will learn about the structure of a DOM document. You will also learn how to use Java technology to create a Document from an XML file, make changes to it, and retrieve the output.
Now on IBM developerWorks: Making of MetroSphere, Part 12: Hands-on JSP technology intro: Creating a community weblog (Tutorial) -- This tutorial is for developers who want to learn more about using JavaServer Pages (JSP) technology to build applications. It discusses the basics of JSP components in general, their integration with JavaBeans, and the creation and use of custom tag libraries.
In the InformIT XML Reference Guide: DOM and Java
Because XML is a platform-independant language, using Java to manipulate it seems a natural choice. In fact, more than one DOM (or more specifically, DOM-like) implementation exists for Java, and the tools necessary for working with it have even been built into the language itself as of version 1.4. ...
Now on InformIT.com: Combining XSL Transformation and Applications -- Using transformations in applications is a powerful tool to control content and handle the presentation of your data. Learn how to not only combine style sheets, transformations, and applications to interact with different sources and outputs, but also how to make transformations more efficient and controllable.
Now on IBM's developerWorks: Create multi-purpose Web content with XSLT (Tutorial) -- As more and more devices become Web enabled, it is crucial that your content be available in multiple forms, such as traditional Web pages, mobile phones or other small devices, or Web services. This tutorial shows you how to set up a Java servlet that detects the type of display that is necessary and automatically produces appropriate markup for the content that uses XSLT.
Now on IBM developerWorks: SAX-like apps in PHP -- While there is no official implementation of the Simple API for XML (SAX) in PHP, PHP does provide a SAX-like method for working with both local and remote XML files. In this article, author Nicholas Chase shows you how to work with XML files in PHP by building and setting handler functions and creating a parser. He demonstrates SAX in PHP with a page-building exercise in which he crafts a page based on the result of an Amazon Web Services query.
Now on IBM developerWorks: Integrating applications with Web services using WebSphere Studio V5 (Tutorial) -- This tutorial shows you how to make your application Web-services ready using the tools in WebSphere Studio Application Developer Version 5. You will learn how to wrap an existing application as a Web service and announce it using a UDDI directory and to discover and use Web services within your applications. The tutorial also explains how to deploy your application to a WebSphere Application Server.
Now on IBM developerWorks: Install and configure Xalan-Java (Tutorial) -- This new tutorial by author Nicholas Chase tells step-by-step how to install, configure, and test the Xalan-Java XSL Transformation processor. Installing Xalan-J involves preparing the environment by obtaining an appropriate Java Virtual Machine, setting environment variables, and installing the files. After installation, you can set other environment variables, such as CLASSPATH.
Now on IBM developerWorks: Tip: Control white space in an XSLT style sheet -- Because the style sheet and the source document in an XSLT transformation have different rules regarding white space stripping, it often seems as though the production of spaces and line breaks has no rhyme or reason in the process. This tip shows you how to control the production of white space in a transformation's result, which can lead to documents that more closely align with your requirements.
Now on IBM developerWorks: Install and configure the Xerces2 Java parser (Tutorial) -- The first step in working with XML is parsing the data into a workable form. This tutorial guides you through the steps necessary to install and configure the Xerces2 Java parser.
Now on IBM developerWorks: Tip: Use imports and includes to override XSLT templates -- Extensible Stylesheet Language Transformations (XSLT) provide two different ways to combine several style sheets in the transformation of a single source document. In the process, it's almost inevitable that more than one template will apply to a single node. Which template is actually applied depends on whether and how the template has been included in the main style sheet. This tip explains how to use these conflict resolution rules to give users control -- but not too much control -- over styling issues.
Now on IBM developerWorks: Tip: Using a DOM NodeFilter -- XML's DOM Level 2 Traversal module provides two new objects, the TreeWalker and the NodeIterator, which simplify the process of navigating a Document. More than that, the module defines a NodeFilter, which can be used to programmatically control what Nodes are visible to the TreeWalker or NodeFilter. This tip shows you how to create a NodeFilter as well as a Traversal object that uses it.
Now on IBM developerWorks: Building an Amazon storefront using SOAP and the WSDK (Tutorial) -- This tutorial is for developers who want to use SOAP to access the Amazon product database through Amazon Web Services (AWS). It shows you how to use the IBM WebSphere SDK for Web Services (WSDK) to create Java classes from the Amazon Web Services Description Language (WSDL) file, demonstrates the use of those classes, and then examines the process of using the WSDK to turn the classes into a Web application and Amazon storefront.