by Aswathi P P (Software Programmer, Excellone Technologies)

A true e-commerce interface required for B2B or retail customers, XML provides the structure for complex data delivery, client side processing and a standard for presentation. The extensibility of XML language makes it a very efficient weapon in the hands of software developers for standardizing the data interchange format among diverse form of industries. When message brokers and workflow engines must coordinate transactions among multiple industries or departments, within an enterprise, they can use XML to join data from disparate sources into a format that is understandable by all parties.

The extensible markup language XML is used to describe the content and structure of data in a document. It is regarded as the industry standard for delivering content on the Internet Applications by providing facility to define the new tags. It describes meaning and the hierarchical structure of data by using tags. For efficient data interchange between the different software applications and systems, advanced data types are used with XML functionality.

The content or data is portable across heterogeneous software applications and system, which ensures separation of the content and presentation. Distinctive XML syntax using start and end tags mark up information. Information delimited by tags is usually known as elements, which is seen in every XML development document. Besides these top-level elements, sub-elements are also seen.

XML development describes content as well as structure of a piece of information, of those which perform these functions separately.

XML Document

DTD’s and Schemas are generally used to describe XML document. DTD (Document Type Definition) defines the basic requirements on the structures of XML documents. It describes the elements and attributes that are valid in an XML document and contents in which they are valid. Or DTD makes it clear as to which tags are allowed within certain other tags and those, which are optional.

Schemas a recent development in XML development specifications, are intended to supersede DTD. They describe XML documents in an elaborate manner. This W3C product, is supposed to cover the limitations of DTDs.

XSL and XSLT

• The Extensible Style Sheet Language (XSL) is W3C standard for describing presentation rules that apply to XML documents.
• XSL includes both formatting and transformation language which functions independently.
• XSLT is XML-based language and W3C specification that describes how an XML document can be transformed into another XML document, or into HTML, PDF or some document format.

Conclusion

It is interesting to see how quickly the XML development standard has been developed, and how a large number of software vendors have adopted the standard. XML development will be as important to the future of the Web as HTML has been to the foundation of the Web. It may also be noted that XML will be the most common tool for all data manipulation and data transmission.