Why Move to XML?
Document designers and authors are motivated to use XML because it provides a means of describing documents, independent of medium. XML documents can be used for print, the Web or any other document medium. This flexibility encourages information system designers to use XML, as they can adopt one set of standards, tools and methods for processing documents, regardless of their various distribution targets. Print and Web authors use XML because it can describe highly structured organizations of data, print to paper and publish to the Web, without sacrificing document structure.
Companies that adopt XML as their primary document format, as opposed to an HTML or word processor environment, should realize a large drop in their document processing costs and gain greater control over the creation, delivery and appearance of their documents. They also inherit a large set of tools that provides document management and processing support which are not available for HTML or word processor formats.
One size fits all users
XML documents can be manipulated to suit the needs of users. It is quite easy to apply a set of different style sheets to an XML document to output to multiple formats or to manipulate content for different audiences.
For example, a writer may want to offer only the exercises contained in a document or only the theoretical components. Provided that a document is appropriately described, the writer can produce any view of document content that they wish. This feature allows various operations to produce vastly different views of the same content for different purposes. When possible, content re-use saves companies money and makes authors more efficient. XML supports and promotes these sorts of processes by being flexible and modular.
The name says it all: eXtensible
XML does not have a fixed number of tags or elements, as HTML does, but it is extensible, allowing the document designer to define meaningful tags. By using XML, developers can develop a markup language that is suitable for their purpose. XML allows developers to build their own set of tags that exactly suit their needs. So while many people do not need tags that support mathematical equations (MathML), the installation of software over the Internet (OSD), and the exchange of financial data (OFX), mathematicians, software developers and financial institutions may need these special tags.
The proof is in the output
XML allows you to separate content from format. The formatting of the XML document is inside a separate style sheet. This separation allows you to easily maintain and update formatting as needs change.
To illustrate the benefits of separating structure from display, we can look at a common scenario that may occur in large and small offices on a regular basis. A document is created that will be needed in several output formats. This document will be needed in the following output formats:
- Web browser
- Online Help
- User Guides
Using traditional methods, a separate document would need to be created for each document type. By separating structure from format, only one source document is needed.
This is the true impact of structured documents. Learning to separate structure from format is critical to making good use of the power of XML.
About the author
This article was originally written by Richard Lander and was updated by Susan Bodnik. Susan Bodnik is an online education instructor and instructor coordinator at Online-learning.com. She holds a degree in English from the University of Waterloo with special research in communications, rhetoric and online learning. She maintains an active interest in evolving technologies related to online education and XML. Susan is involved in all aspects of course development, quality assurance, delivery and evaluation.