[InfoWorld] Review of XML Authority, for Schema maintenance

Rohit Khare (rohit@uci.edu)
Mon, 6 Dec 1999 22:04:10 -0800

Extensibility upgrade takes XML forward
By Todd Coopee , For InfoWorld Test Center

XML Authority 1.1


This schema development tool helps develop and maintain XML-based
languages and vocabularies. Its GUI-based programming environment
offers syntax checking, import and export options, and documentation


XML Authority's bevy of features should speed XML schema development.
This will translate into lower development costs for corporate XML


+ Import and export options
+ Visual schema representation


- Online documentation needs work
- Lacks full-featured workgroup functionality


Single user: $99.95; 10 users: $849.95; 50 users: $3995


Windows 95, 98, or Windows NT 4.0; Unix; Linux; Mac OS.

Extensibility Inc., Chapel Hill, N.C.

WHEN IMPLEMENTED on an enterprisewide scale, Extensible Markup
Language (XML) can provide the ties that bind together heterogenous
data services and systems; in fact, its proponents are downright
giddy over its promise of platform-and presentation-independent data
interchange. But XML programming is no walk in the park, and without
the right tools you can spend a lot of time and money and end up with
little to show for it.

Enter Extensibility's XML Authority 1.1, a major update to the
company's schema design, conversion, and management tool. Designed to
help companies reduce the development time of vocabularies and
grammars -- XML-based domain-specific languages -- XML Authority 1.1
is an obvious step up from Extensibility's initial release. New
documentation, syntax checking, and import/export features make XML
Authority 1.1 well worth the upgrade, particularly for sites involved
in major XML development projects, although some areas could use
further development, most notably the online help system. XML
Authority is not intended for the novice; it assumes a working
knowledge of the XML nomenclature and an understanding of schema
design basics.

Since the XML specification became a World Wide Web Consortium
recommendation in April 1998, several powerful domain vocabulary
specifications have emerged for approval, including the Synchronized
Multimedia Markup Language and the Precision Graphics Markup Language.

Using schemas, XML Authority authors, documents, and maintains these
and all languages based on the XML 1.0 specification. Similar to data
models, schemas are graphical representations of the vocabulary and
structures that appear in documents using that schema. Document sets
conforming to the same schema may contain different information but
share common processing. A schema for purchase orders (POs), for
example, would describe a class of documents that have very different
contents (sender, recipient, prices, taxes, or total) but have the
same structure, and so can be processed by any number of generic
tools for handling POs.

However, even seasoned professionals may find the help section a bit
pedestrian. It contains a confusing mix of marketing messages and
help text, and some documents contained misspelled words. Further,
printing online documentation was dicey; for example, repeated
printings of the "Hows and Whys" document produced only half of the

Nevertheless, XML Authority is flexible; its user interface allows
you to build and see schemas from a variety of perspectives. Also,
the product's screen layout is basic and uncluttered, comprising a
set of windows, panes, and drop-down menus.

When the application is first launched, the Welcome window appears.
From there, you can open an existing schema or create a new one from
scratch. Authoring a new schema begins in the Elements Types pane,
which includes a list of items, such as Element Type and Content
Model/Data Type, that can be edited, plus a "selector" button (for
selecting items to cut and paste) that turns red when there's an
error in your declarations. By employing a spreadsheet metaphor, the
product lets you sort declarations by clicking on column headers.

Depending on your element type, context-sensitive information appears
in the Content Model/Data Type column to provide quick access to
available data types. For example, a Qlicker -- a menu from which you
can select data types -- appeared when I created a text element
called "angle." This Qlicker let me choose from a list of available
data types, such as string, integer, decimal, boolean, date, and
time. Using Qlickers will definitely reduce your development time.

Once you begin using XML Authority, it is very easy to see how useful
it is as a development tool. It provides support for namespaces and
data typing within Document Type Definitions. You can also create
libraries of reusable modules that can be shared across multiple
schemas, so you don't have to reinvent the wheel for successive
projects. In addition, schemas can be exported in several formats,
including BizTalk and Sox, Versions 1.0 and 2.0.

During the authoring process, XML Authority performs syntax checking
in real time, ensuring that your schema is always valid. All of the
errors XML Authority finds are displayed in the Errors pane. Further,
Syntax checking is especially handy when you import a large schema
from an outside source.

The tool's documentation facilities impressed me. The source pane
lets you preview schema source code and edit declarations on the fly,
and a Notes pane lets you document structures. You can also select
individual declaration types to be printed or saved in HTML format.

XML Authority offers limited workgroup features. For example, it
supports versioning and change-logging but does not let you check out
a document for exclusive use.

For developing and documenting XML schemas, XML Authority 1.1 is a
well-rounded, capable tool. XML development is not a trivial
exercise, and this tool helps to significantly simplify the process.

Todd Coopee is the technical director at Industrial Media, a new
media consultancy in Ottawa.