1. Extensible Markup Language Natawut Nupairoj, Ph.D. Department of Computer Engineering Chulalongkorn University

2. Outline Overview. Basic XML Syntax. User-Defined XML Structure  Document Type Definition.

3. Overview What is Markup Language ?  Old style communication for editing.  Between writer and editor.  Example: This are is a mark-up. We can more text. add Sometimes, called “Metalanguage” ^

4. Overview Family of Computer Markup Language  Standard Generalized Markup Language (SGML) Father of them all. Complex.  HyperText Markup Language (HTML) The most popular child. Focus on presentation: for human.

5. Overview  Extensible Markup Language (XML) Become increasingly popular. Similar to HTML. Focus on describing data  For human and machine. Extensible  Language for creating other languages.  Base syntax.  User-defined structure.

6. Example Tiger pantera tigris poachers habitat destruction trade in tiger bones for traditional Chinese medicine(TCM) 500 pounds 3 yards from nose to tail...

7. XML Siblings XML Structure Definition  Document Type Definition (DTD).  XML Schema. XML Parser  DOM.  SAX. XML-related technologies  XSLT.  XPath.

8. XML Components Element: tag and content  Data. Tiger

9. XML Components Attribute: name and value  Metadata = Data of Data. Tiger English Tiger

10. XML Components Nested element Tiger Panthera tigris 500 pounds

11. XML Components Empty element

12. XML Components Special symbols  & for ampersand (&).  < for less than sign (<).  > for greater than sign (>).  " for double quotation (“).  &apos; for single quotation or apostrophe (‘). <500 pounds

13. XML Components Comment

14. Basic XML Syntax All XML files/applications must conform to basic XML syntax  XML declaration is not required (but recommended). Tiger

15. Basic XML Syntax  One and only one root element. Tiger

16. Basic XML Syntax  Balanced and matched opening/closing tags. Tiger

17. Basic XML Syntax  Case-sensitive. Tiger  Case-sensitive.

18. User-Defined XML Structure XML basic syntax  The pattern of all XML documents.  Does not say about “structure”.  Followed basic syntax = well-formed document. User-Defined XML Structure  Which “tags” and “attributes” are allowed.  Describe the structure.  Followed “structure” = valid document.

19. Parser and DTD XML Parser XML Document Yes/No DTD Check input using basic syntax and DTD.

20. Document Type Definition (DTD) Old-fashioned, simple, but widely used. Internal DTD. <!DOCTYPE endangered_species [... ]>...

21. Document Type Definition (DTD) External DTD. <!DOCTYPE endangered_species SYSTEM “http://www.natawut.com/xml/my_xml.dtd”>...

22. Defining Elements

23. Defining Elements Tiger 500 pounds...

24. Defining Elements Tiger poachers 500 pounds...

25. Defining Elements 500 pounds 3 yards from nose to tail

26. Defining Elements

27. Defining Attributes 445

28. Defining Attributes

29. Defining Attributes

30. Putting Them Together...