1. 1 XML An Overview Roger Debreceny University of Hawai`i Skip White University of Delaware XBRL Workshop, August 2006

2. 2 XML The eXtensible Markup Language

3. 3 Markup languages What is a markup language?  Markup languages “markup” text (data) so that one string of text can be distinguished from another!  What does the following mean? 141 68 7.5

4. 4 XML Markup language  Could be anything – space, comma, tab, …  Need agreement on the markup! eXtensible  Able to “extend”  Need agreement on the markup rules! 141 68 7.5

5. 5 HTML HyperText Markup Language  An agreed-on language for creating Web pages  A fixed set of tags as markup My Web Page Hello – Welcome to my Web page!  Tells a browser how to display things!

6. 6 XML - markup for documents The markup rules & syntax that all “well- formed” XML documents must follow:  One and only one root element  All elements must be properly nested  All non-empty elements must have the same beginning and ending tag names (case-sensitive)  Elements can contain data items or other elements (mixed is considered bad form)  All elements can contain attributes

7. 7 XML Elements The basic unit of all XML documents is the “element”  A root element Is the master element … the overall “container”  Its name tells what the document is all about  Simple elements contain data values and do not have attributes 12345  Complex elements have attributes and/or other elements nested within 12.00  12345  12.00 

8. 8 XML document (part 1)  12345  Skip  White  1234 Main Street   Newark  DE  19716  USA 

9. 9 XML document (part 2) 111 2006-08-02 Skip White 1234567891011213 2009-05 srh123 Specialized RH Mountain Bike 19 1 550.00

10. 10 XML documents What can we say about XML documents?  XML documents are made up of tags (markup) that add meaning/context to data items A pair or tags and its content is known as an element  XML elements can contain attributes within the beginning tag – attributes add meaning! The XML attribute format is: attributeName=“value”  XML documents are structured in a strict hierarchy  Well-formed XML documents can be processed by an XML processor

11. 11 XML Documents Why are XML documents so popular for storing and transforming information on networks?  Easy to create & understand  Contain data with meaning & context Processing data as information  Very efficient for computers to process  A standardized and non-proprietary language

12. 12 XML Fundamentals XML documents are hierarchical  Structured as tree-like hierarchies XML documents are self-describing  Each piece of data (information) has descriptive information associated with it XML is directly usable over the Internet  Designed for storing & delivering information XML does not currently replace HTML  XML describes the content while in most cases HTML is used to tell a browser how to display it

13. 13 Information in XML Documents So … What do you have when you have information in XML documents?  You have information that can be understood by humans as well as ANY COMPUTER APPLICATION!!!  XML is being referred to as the Rosetta Stone of networked computing! The transfer of information between computer applications and between computers and humans will become much more intelligible and automatic

14. 14 XML specifications XML is a set of rules and syntax for creating XML documents and specifications (stds.) that extend the capabilities of XML  XML documents are used to store and transfer structured data over computer networks  XML specifications extend the basic rules of XML to create languages & vocabularies to be used to: Define the contents & structure of XML documents Process XML documents Create languages to support XML document processing

15. 15 XML Specifications XML Schema language  To define the allowable contents & structure of XML documents & to create additional XML specs. XML Namespaces (xmlns)  A collection of element names & attributes for a particular purpose - like business reporting & they help to avoid naming collisions! XML Linking Language (XLink)  Attributes to be used to define sophisticated links between networked resources XBRL – a special purpose XML vocabulary!

16. 16 XML namespaces The naming collision problem:  What if within your company, you have an accounting department & a shipping department and they each want to use the XML element name “status” to mean things uniquely relevant to them? In accounting, status is used to mean billed or not! In shipping, status is used to mean shipped or not!

17. 17 XML namespaces The solution  Create a separate namespace for each department & within each namespace, define the element name “status”  myCompany.com/xml/accounting Preferred namespace prefix: acct billed (notBilled)  myCompany.com/xml/shipping Preferred namespace prefix: ship shipped (notShipped)

18. 18 XML namespaces in XML docs. (a sales order status report) <SalesOrderStatus xmlns:acct=“http://myCompany.com/xml/accounting” xmlns:ship=“http://myCompany.com/xml/shipping”>  12345  2006-08-02  shipped  notBilled 

19. 19 XML Namespaces XML namespaces  Contain a collection of elements & attributes for a particular purpose  In XML documents: Namespaces must be declared using the xmlns attribute (usually declared in the root element)  xmlns:prefix=“http: namespace URI” After declaration, a namespace prefix can be appended to an element or an attribute – designates that it was defined in a particular namespace (for a particular purpose)  10000

20. 20 XLink language The XML XLink language  A link is an explicit relationship between any addressable resources – information or services  The XLink specification defines a set of attributes that can be used with any XML element to create explicit relationships  Simple links (commonly seen on Web pages) are unidirectional from a source to a target doc.  Extended links are two-way and multidirectional and can describe relationships

21. 21 Xlink language XLink is used heavily in the XBRL specification (& in XBRL documents)  To link a taxonomy to an XBRL instance document 10000  To define relationships between facts reported in an XBRL instance document  To create “linkbases” to provide additional information about accounting concepts in instance documents

22. 22 Summary – Introduction to XML XML is a set of rules and syntax for creating XML documents and specifications (stds.) that extend the capabilities of XML  XML documents are used to hold and transfer structured data over computer networks  XML specifications extend the basic rules of XML to create languages & vocabularies XML Namespaces XML XLink language XML Schema language XBRL – a special purpose XML vocabulary

23. 23 Reference material W3C Schools – XML tutorial: http://www.w3schools.com/xml/default.asp http://www.w3schools.com/xml/default.asp W3C Schools – HTML tutorial: http://www.w3schools.com/html/default.asp http://www.w3schools.com/html/default.asp HTMLHelp.com – HTML references & tutorials: http://www.htmlhelp.com/ http://www.htmlhelp.com/