XML tools: Who knows where or when?
- By Johanna Ambrosio
One of XML’s core strengths can also become a source of confusion. People have
begun using the language for so many different things -- structured and unstructured
content, app integration and workflow -- that the ways in which developers work
with it vary widely.
Some use XML-specific tools ranging from parsers to those that help with data
transformation or integration, to content management software and workflow managers.
Others opt for a fuller-figured XML development toolkit, analogous to an IDE.
Some go the freeware route, or use text editors they already have, including
emacs and vi.
But is new, XML-specific tooling necessary? Would it not be more efficient
to use the development environment already in-house rather than spend time learning
a new one?
The answer, industry watchers and customers say, depends on what you are doing
with XML and the level of functionality built into your existing tools. There
are good reasons to start with what you already have, and there are equally
powerful motivations to adopt a separate, XML-focused suite.
The conundrum was summed up by Uttam Narsu, vice president at consultancy Forrester
Research in Cambridge, Mass. While the XML-specific toolkits will often provide
rich schema and design choices, they do not necessarily “connect up to everything
else,” he said. “How do you interact with XML from an existing Java program?
Many of the choices are quite painful.”
On the other hand, today’s existing IDEs often do not “give you enough XML
design or management facilities,” he noted. This choice can leave users who
are doing heavy-duty XML between a rock and a hard place.
Rikki Kirzner, research director for app development and deployment at Framingham,
Mass.-based consultancy IDC, puts it this way: “There’s no general rule; it
goes project by project. But the major question is: How specific do you need
to become in your XML implementations or conversions?”
There are a lot of vertical takes on XML these days, for everyone from aviation
to financial-services and high-tech manufacturing firms. If you are doing document
conversion or sharing across multiple companies, you may well need an XML tool
that allows you to implement or transform a specific vocabulary or schema.
But if it is something more general, like wrappering XML for a Web services
app, “then pretty much all the big players have a very credible offering built
in,” Kirzner said. Popular development tools from Borland, IBM, Microsoft and
others already have various levels of XML support; whether you require more
than that is a function of what you need to achieve and how extensively you
need to manipulate, change or otherwise transform XML.
In general, “the need for standalone XML tooling was more acute in the early
days when XML was identified as a separate thing,” said Ronald Schmelzer, a
senior analyst at ZapThink LLC in Waltham, Mass. “These days, people expect
tooling to be part of their existing” development environment, he said.
Indeed, Sandra Rogers, director of the Web services program at IDC, said her
research confirms that “most people are using general tools, not Web services-specific
types of tools” when it comes to XML. “They see it as an extension of their
existing tool environment.” The exception: integration types of projects, when
it is “more important to be specific” to ensure the technology covers the different
databases or information types that need to be integrated.
Differences in approach
There may be other times when an XML-specific development environment is called
for. Jonathan Robie, editor of several XQuery specifications, is XML program
director at DataDirect Technologies, a Rockville, Md.-based vendor working on
products that integrate XML and other data sources. He said he uses an XML-specific
IDE “about half the time.” It helps to visualize relational schemas, XML schemas
and the structure of XML files. Some XML IDEs allow you to generate code fragments
simply by dragging structures into the code window, said Robie, which saves
time and ensures that the paths are correct. And if the XML IDE also includes
a good debugger, it is much easier to find bugs in the code.
And that is the crux of the difference between general application development
tools and many of those that are specific to the XML world, he explained. “XML
tools help you to visualize what you’re trying to do, because you can actually
see XML. It’s both a machine- and human-readable language.” An XML IDE helps
programmers to see both the data and the effects of each step in the transformation.
For their part, traditional programming environments are more about optimization
and debugging than they are about visualization, Robie said.
For beginners particularly, one of the big benefits of an XML IDE is that everything
is easy to install and “it all just works,” he noted. “Many XML gurus work with
a programmer’s editor, Ant files or Makefiles, and a variety of separately installed
tools, but that takes some time to set up and understand.”
Not an either/or proposition
Another factor to consider is that choosing an XML-specific toolkit does not
necessarily mean it has to be entirely separate from your existing development
environment. Altova’s XML Spy product, for example, is integrated with Microsoft’s
Visual Studio.NET (VS.NET). So if a VS.NET user is working on an XML file, he
can get XML Spy as the visualization and debugging environment for SOAP and
XSLT -- within the familiar VS.NET interface.
“On the Java side we don’t have anything as tight as that, but we are cooking
some things up,” said David Kershaw, manager of education and professional services
at Altova in Beverly, Mass.
There are other motivations for specific XML tools, he said. It just does not
pay a general tools vendor to focus as deeply as a vendor devoted to the XML
and Web space, he noted. XML just “won’t ever be the highest priority” to a
big development name like Microsoft or IBM, Kershaw said, as it is to a company
that makes its living from XML.
Further, “there just aren’t that many tools to treat schemas the same way as
we do for software code, components or classes,” he said.
At the same time, however, even Kershaw admits that Altova’s bread-and-butter
customer is someone who spends virtually all of his or her time with XML. “We
don’t pretend we’re a general-purpose IDE for Java or C++ code,” he said. “We’d
rather plug into Visual Studio than replicate all that structure.”
Another point is that XML-specific tools are “what keeps people honest” after
using the wizards and other features found in the general-purpose IDEs. “In
the XML world, you may have a valid WSDL file, but not a completely correct
WSDL file,” he said. “After I create something in VS.NET, I can go over to XML
Spy to make sure it really does what I think it does.”
Finally, Kershaw suggested, “it’s difficult to make a really good XML schema
editor -- that’s a serious modeling task,” and it is not something that all
the tools do equally well.
The case for general tools
Be that as it may, IBM, Oracle and some other traditional tools vendors are
making a case for integration. It is only with an environment that handles XML,
SQL and other types of information -- all together -- that many pieces of a
complex development problem can be provided, they say. And that is best handled
with a general IDE that has XML features and functions built in.
“Integration is very important,” said Ted Farrell, architect and director
of strategy for Oracle’s tools group. “We don’t have the luxury of only XML
or content or software; systems are being built that are a combination of all
of those things. So the problem is complicated.” This, in turn, requires tooling
that “knows about” different types of information.
The new mantra from Oracle is “productivity with choice,” Farrell said. “Our
tools are separate from the runtime environment” so customers can opt to go
with a specialized XML tool to, say, define a schema that can later be brought
into Oracle’s JDeveloper for transformation and other tasks. “If we’re all using
the same file, you can check them in, then I can take them and extend them”
via Oracle’s own toolset, he said.
Arthur Ryman, WebSphere Studio Development lead at IBM, explained that “what
we’re pushing now is how XML is integrated into the programming model.”
This helps customers to do more complex builds like turning XML into HTML.
“We created point XML tools early on,” he said, but nowadays the real value
to customers is that XML is just one part of the overall WebSphere environment.
“If you’re writing XML, it’s in relation to something else,” he said.
“You can’t look at XML as some isolated technology with its own specialized
toolset,” Ryman said. “It’s just one of many technologies you need to get the
job done.” Perhaps it is to help integrate Java and CICS applications, or to
work with EJBs on the back end, or to integrate XML with stored database procedures.
“It really is an integrated development effort, and you need an integrated development
environment,” he explained.
That integration is getting more pervasive. Coming up in a future version of
WebSphere Studio will be a debugger that can handle both Java and XSL, “so you
can extend XSL to call out to Java functions,” Ryman explained. “So if I can’t
express something easily in XSL, I can write a Java function. In our debugger
framework, it’s all seamless.” With standalone XML tools, “you don’t necessarily
get good integration with the underlying languages,” he said.
Microsoft’s view of the XML world
Like many of the general tools vendors, Microsoft is embracing XML “whole hog,”
even though it is fairly early going. “There’s a lot of excitement around XML
right now, but there hasn’t been widespread adoption yet,” said Tom Rizzo, director
of product management for SQL Server. “You want XML to be pervasive yet cost-effective,
because it’s an enabling technology” for so many other things, he said.
On the first rung is support with the Office suite, so business users can turn
Word and other documents into XML, with Office handling the conversion behind
the scenes so users do not need to touch the language directly. “End users don’t
ever want to actually see XML itself,” Rizzo joked.
On the next rung is support within VS.NET, which includes an integrated XML
editor as well as support for many of the XML object models, including XPath,
XML DOM and others. Microsoft will support XQuery “when it becomes a finalized
standard,” Rizzo promised. “We have a beta on our Web site, but it’s not final
On the storage side, SQL Server stores XML documents and can run queries against
them. Rizzo promised even “tighter integration” between the SQL and XML worlds
in the next release of SQL Server, due for commercial release by the end of
this year. In that version, users will be able to do cross-domain queries and
cross-domain insertions of both XML and SQL data.
“Let’s say you have a customer database -- with name, phone number and addresses.
But maybe you’d want to store an XML column in that database with demographic
information that’s stored in XML because it could change. So you could do a
selection of the top 10 customers and at the same time filter it with demographic
data, too,” he said.
For industry-specific versions of XML, there is Microsoft’s BizTalk Server,
which can take proprietary or vertical schemas and then convert proprietary
information to those schemas or industry standards. The next version of BizTalk,
“due out pretty soon,” will make it easier to “build those transforms between
XML and to orchestrate transforms,” Rizzo said.
Overall, Rizzo said, Microsoft’s XML support meets “80% to 90%” of customers’
Different XML needs may require different tools
In general, there are two types of XML users, say Oracle’s Farrell and others:
business analysts who like XML’s flexibility to deploy code once to many different
kinds of platforms, and the programmers and serious XML coders who are using
the language directly.
For the first set of users, visual and other “light” tools may be needed more
than for the second batch of heavy-duty programmer types. From this second group
of users arises a call for better schema manipulation and editing, as well as
better transformation mapping. “No one feels this is done very well across the
board; different products map these transformations, but all the tools have
their limitations,” Farrell said.
It is precisely because of these different types of XML users that the world
is moving in two directions. One is increased functionality and integration
for the heavy-duty XML coder. And then there are the larger numbers of visual
tools for business analysts and others who want to map vendor, product or part
number and then parse or merge those elements into an application. They do not
want or need to know how XML works, only that it does.
IDC’s Rogers explained that her research suggests that “many people want to
have their XML or SOAP code automatically generated from a modeling tool, and
then be able to get into that code both graphically and in the traditional coding
way. And they want it bi-directional, so if there’s a change it shows up both
graphically and in the code itself.”
But it is going to take a while for the technology to become that sophisticated.
Until it does, XML developers already have many choices in their arsenal. As
IDC’s Kirzner said, “if I need more than the standard eight crayons that come
with the coloring book, I can always go out and buy the box with 64 crayons.
And then maybe some magic markers, too.”
Please see the following related story:
"OneFamily, one connection layer" by Johanna Ambrosio