XML Vikki Brandon Jesse Josh

Quick Facts Who created it? –W3C Jon Bosak and Tim Bray as leaders and major contributors When? –Started in 1996 and finished in 1998 What is it? –Extensible Markup Language “A new language designed to make… information self-describing.” – Bosak and Bray

Why?

The Problem SGML –Standard Generalized Markup Language –Used for large technical documentation –Too general “Full of clever features designed to minimize keystrokes in an era when every byte had to be accounted for. It is more complex than Web browsers can cope with.”– Bosak and Bray

The Problem HTML is inflexible and slow –Concerned with appearance, not content –Difficult to add markup tags TAGS: used to describe/single out data in a document or file –Slow Must resend information when changes are made PC sits idle while waiting for a response Example

The Solution: XML

Derived from SGML without the complexity Tags in XML –Ordinary text Human Readable and Understandable Concerned with content, not appearance Output to multiple devices and formats –Including different languages and audio –Data is formatted by the device PDA, Cell Phone, Laptop, PC, etc.

The Solution: XML Faster…to a point –On the spot processing Data packet can include a parser or small program to manipulate the data without referencing the server Uses DTDs (Document Type Definitions) which function as “Rosetta stones" that enable computer programs to understand particular XML-based languages. Example

Programmer’s Design Goals XML shall be straightforwardly usable over the Internet. XML shall support a wide variety of applications. XML shall be compatible with SGML. It shall be easy to write programs which process XML documents. The number of optional features in XML is to be kept to the absolute minimum, ideally zero. XML documents should be human-legible and reasonably clear. The XML design should be prepared quickly. The design of XML shall be formal and concise. XML documents shall be easy to create. Terseness in XML markup is of minimal importance.

Tools and Applications MathML, XBRL, Government

MathML MathML is an application of XML intended to make possible the use of mathematical and scientific content on web pages. –consists of a number of XML tags which can be used to represent an equation; –On traditional Web sites, images must be used to portray all but the simplest mathematical expressions.

x 2 + 4x + 4 =0 x x + 4 = 0

XBRL eXtensible Business Reporting Language is a language for the electronic communication of business and financial data. –Instead of treating financial information as a block of text like it is in a standard internet page or a printed document, it provides an identifying tag for each individual item of data. This is computer readable. For example, company net profit has its own unique tag. Example

XML For Legislative Documents The United States Congress is taking advantage of XML with its new web page xml.house.gov. –The public web site provides a number of XML DTD’s for bills, resolutions, house membership, etc. The document type definitions presented on this site were developed at the U.S. House of Representatives by employees of the Federal Government.