Introduction to XML MIS3502: Application Integration and Evaluation Paul Weinberg Presentation by David Schuff

A brief look at XML Extensible Markup Language Considered to be a future standard for sending structured data over the web From browser to person (business to consumer) From application to application (business to business) “Cousin” of HTML

Where XML fits in Standard Generalized Markup Language (SGML) Specification for some kind of text and tags Hypertext Markup Language (HTML) Definition of specific tags for formatting web pages Extensible Markup Language (XML) Specification for defining your own tags for formatting data SGML HTML XML

Simple XML Example If this table were an XML document, it would look like this: John /16/45 Ringo /11/72 Paul /20/50 and so on…

XML Schemas The XML tags mean nothing on their own Something needs to define what tags are relevant for a particular document XML Schemas are the metadata for XML XML Schema for a Beatle

How does this help? XML facilitates standards XML is self-describing XML is flexible Industries can decide on a standard Schema All messages can follow that standard Makes sending data between companies easier Order processing Airline reservations

Example: Fixed Length Records Versus XML Using Fixed Length Records: David Schuff Fox School First Name, Characters 0-9 Last Name, Characters SSN, Characters School Name, Characters You have to hard code where the fields start and their length, so the application knows which characters belong to which fields. What if I have a 15 character last name? What if the last name is provided before the first name?

Example: Fixed Length Records Versus XML Using XML: David Schuff Fox School Because I have the DTD and use tags to match characters with data fields: I don’t care how long each piece of data is. I don’t care what order it arrives in. Extra fields can be included – I just retrieve a modified DTD.