XML FUNdamentals: A Tutorial by Web Financial Solutions

You’ve probably heard the term XML sometime in the last year or so. And you may (or may not) be wondering what this is all about. Is it some kind of new �computer language�? What does it really do? How does it affect me and solve my problems?

This column is intended to address those kinds of questions. Firstly, we want to explain a few fundamentals about XML and then, most importantly, we want to apply the capabilities and benefits of XML to common business problems. This column will begin by explaining what XML is and what XML isn�t.

What XML is

Extensible Markup Language (XML) is a structured plain text format for encoding information that can be easily read and processed by a computer. This allows a computer to generate data, read data, and ensure that the data structure is unambiguous. It is similar in some respects to its cousin � HTML. However whereas HTML is intended to describe how data should be displayed within a web browser, XML is intended to be an extensible format for describing the data and the data structure.

XML was originally envisioned as a language for defining new document formats for the World Wide Web. It is considered a meta-language: a language for defining markup languages. But it is also suitable for describing structured data, such as financial transactions, technical drawings, program configurations and network protocols. XML can easily represent tabular data like tables and spreadsheets, as well as broader structures, like business documents and Web pages.

The fact that XML is in plain text format means that when required, XML documents can be read by humans and edited using standard text-editing software. This enables applications to be debugged more easily by programmers.

XML is extensible: unlike HTML, it does not have a predefined set of tags. Instead, one can �invent� their own tags and document structure specific to particular business needs or industries. XML makes use of tags only to delimit data, and leaves the interpretation of the data completely to the application that reads it.

XML is platform-independent. This means that XML documents may be produced or consumed using a wide variety of programming languages, which makes it very effective in achieving interoperability between platforms and operating systems.

XML is well supported by a large and growing community of commercial and open-source vendors. It is license-free, allowing you to create applications around XML without spending a penny. XML is rapidly becoming the standard representation format for data manipulation and transmission.

What XML isn�t

XML is not a programming language, therefore it does not �run� or �execute�, and you do not have to be a programmer to use it.

XML is not tied to any specific language, operating system or software manufacturer, so you will not be tied to any single vendor.

XML does not replace HTML. Although both are markup languages and both make use of tags, they were designed for different purposes. HTML defines how data will be displayed, whereas XML describes the data structure. HTML tags are predefined according to an HTML standard, whereas XML tags must be defined by the author of the XML document and are specific to the application.

XML does not actually do anything on its own. It is just pure information and it relies on a software application to display or invoke it.

XML is not a single entity, but rather a family of technologies that offer important services for manipulating, transforming and querying data: Xlink describes a standard for adding hyperlinks, Xpointer aids in pointing to pieces of data inside an XML document, XSL is an advanced language for expressing style sheets, and XML Schemas define the structure and content of XML documents.

An Example

Below is an example of how an automobile would be represented in XML:

Here is the example:

To illustrate how XML could be used to represent structured data let�s consider representing an automobile.

<automobile make=�Oldsmobile� class=�midsize�>
   <model>Cutlass Ciera</model> 
   <engine size=�3.01� cylinders=�4� />
   <transmission type=�standard� />
   <doors count=�4� />
   <options>
      <airconditioning />
      <sportpackage />
   </options>
</automobile>

This is just one way in which the data could be represented and it is not a comprehensive example but it is easy to see how this simple structure could be extended to describe any type of automobile.

Summary

As we have seen XML offers the ability to interconnect systems together using a standard format. The benefit of this method is a faster and standards based approach for sharing information on multiple systems. This sharing of information will allow for the creation of new applications that will gather their information from powerful legacy systems.

About Web Financial Solutions

Web Financial Solutions (WFS) is a Canadian owned and operated company that helps financial services companies become stronger through the development of technology-based business solutions. One of WFS� specialties is systems integration to connect legacy systems using the CSIO XML Standard. The implementation of this standard will allow for the creation of a Policy Change Systems that are accurate, scalable, cost-effective, efficient and easy to use. WFS utilizes customer-tailored versions of the Rational Unified Process to create Enterprise J2EE and WebSphere solutions. For more information, visit www.webfinancialsolutions.com.