โดย อ.ประพจน์ สุขมานนท์

1. eXtensible Markup Language

2. Markup Language
GML
SGML
WML
..ML

3. Markup Language
A Markup Language is a computer
language that specifies the structure
and content of a document by breaking
the document down into the series of
elements

4. XML
XML stands for eXtensible Markup Language
XML is a markup language much like HTML
It’s a new markup language,developed by the
W3C(www.w3.org),mainly to overcome limitations
in HTML
XML was designed to describe data
XML tags are not predefined in XML.You must
define your own tags

5. XML & HTML
HTML and XML were designed with
different goals
HTML was designed to display data and to
focus on how data looks
XML was designed to describe data and to
focus on what data is
HTML is about displaying information,
XML is about describing information

6. XML & HTML
HTML tag : pre-defined tag
<b>John</b>
XML tag : user-defined tag
<Name>John</Name>

7. Markup Language Example
Markup
Language
HTML XML
<b>025447891</b> <myphonenumber>025447891</myphonenumber>

8. XML Example
XML
xml01.xml
<?xml version=“1.0”?>
<employee>
<id>001</id>
<name>Prapoj Sukmanont</name>
<city>Bangkok</city>
<email>prapojs@hotmail.com</email>
</employee>

9. Element Structure
Element Name
<tag> Content </tag>
Open Tag(start-tag) Close Tag(end-tag)

10. XML Structure
<?xml version=“1.0” ?> root
<root>
<child>
<sub_child>
</sub_child>
</child> child child
<child>
<sub_child>
</sub_child>
sub_child sub_child
</child>
</root>

11. XML File Structure
File name : *.xml
Prolog
Document Elements

12. Prolog
XML Declaration
<?xml version=“1.0”?>
Document Type Declaration
<!DOCTYPE PurchaseOrder SYSTEM “po.dtd”>
Processing Instruction(PI)
<?xml-stylesheet type=“text/css” href=“test.css”?>

13. Document Elements
<employee>
<id>001</id>
<name>Prasit Lee</name>
<city>Bangkok</city>
<email>prasitl@hotmail.com</email>
</employee>

14. XML File Structure : Prolog
File name : *.xml
1. XML Declaration Prolog
2. Document Type Declaration (DTD)
3. Processing Instruction (PI)
Document Elements

15. XML Example
xml01.xml
<?xml version=“1.0” ?>
<employee>
<id>001</id>
<name>Prasit Lee</name>
<city>Bangkok</city>
<email>prasitl@hotmail.com</email>
</employee>

16. Thai Language XML Example
xml01th.xml
<?xml version=“1.0” encoding=“windows-874”?>
<employee>
<id>001</id>
<name>ประสิ ทธิ ลี</name>
<city>กรุ งเทพ</city>
<email>prasitl@hotmail.com</email>
</employee>

17. XML Benefits
Self-describe Data
Data Exchange
XML Benefits
Messaging Format for Application
So on…
(RSS, ebXML, XML Applications…)
CML, MathML, MusicML, VoiceML …

18. Text File & XML File
employee.txt employee.xml
Text File XML File
<?xml version=“1.0” ?>
1,John,Bangkok <employee>
2,David,New York <id>1</id>
3,Peter,London <name>John</name>
<city>Bangkok</city>
<id>2</id>
<name>David</name>
<city>New York</city>
<id>3</id>
<name>Peter</name>
<city>London</city>
</employee>

19. Data Exchange Example
DB Server 1 DB Server 2
XML Parser employee.xml XML Parser
XML File
Database <?xml version=“1.0” ?>
Database
<employee>
<id>1</id>
<name>John</name>
<city>Bangkok</city>
<id>2</id>
<name>David</name>
<city>New York</city>
<id>3</id>
<name>Peter</name>
<city>London</city>
</employee>

20. XML Processor
After the XML document is created, it needs
to be evaluated by an application known as
an XML processor or XML parser
Part of the function of the parser is to
interpret the document’s code and verify that
it satisfies all of the XML specifications for
document structure and syntax
Microsoft developed an XML parser called
MSXML (msxml.exe) for its Internet Explorer
browser

21. Well-Formed XML
“A Well-Formed XML document contains no syntax
errors and satisfies the specifications for XML codes
as laid out by W3C”

22. 1. Root Element
<?xml version=“1.0” ?>
<employee>
<id>001</id>
<name>Prapoj Sukmanont</name>
Root Element
<city>Bangkok</city>
<email>prapojs@hotmail.com</email>
</employee>

23. 2. Element Naming
XML elements must follow these naming rules
Names can contain letters,numbers, and
other characters.Names must not start with
a number or other punctuation characters
Names must not start with the letter
xml(or XML or Xml ...)
Names cannot contain space,(*,? And +)
Avoid “-” and “.” in names
The “:” should not be used in element
names

24. Element Naming : Example
<-Company>
<9Company>
<Company> <.My_company>
<_Company> <Name*>
<My_company> <Name?>
<First-name> <Name+>
<Last.name> <xmlbook>
<first name>
Not OK
OK

25. 3. Closed Tag
<?xml version=“1.0” ?>
<employee>
<id>001</id>
<name>Prapoj Sukmanont</name>
<city>Bangkok</city>
<email>prapojs@hotmail.com</email>
</employee>

26. 4. Proper Nesting Tag
<ID>
<ID>
<name>
<name>
</ID>
</name>
</name>
</ID>

27. 5. Case-sensitive
<ID>
<ID>
<name>
<name>
</Name>
</name>
</ID>
</ID>

28. 6. Attribute Value
<employee id=“001”>
<name>
<employee id=001> </name>
<name> </employee>
</name>
</employee>
<employee id=‘001’>
<name>
</name>
</employee>

29. Element Attribute
An attribute describes a feature or characteristic of an element .Attributes
are often used to provide additional information about an element .The
syntax for adding an attribute to an element is
<element_name attribute_name=“Attribute value”> … </element_name>
Attribute name constraints:
The name must begin with a letter or underscore (_)
Space are not allowed in attribute names
Attribute names should not begin with the text string “xml”

30. Well-Formed XML Example
Well-Formed
XML
xml02.xml
<?xml version=“1.0” ?>
<employee>
<id>001</id>
<name prefix=“Mr”>Prapoj Sukmanont</name>
<city>Bangkok</city>
<email>prapojs@hotmail.com</email>
</employee>

31. XML Element Types
Normal element
<Name>Prasit Lee </Name>
Empty element
<telephone></telephone>
<telephone/>

32. Element Content

33. Element Content
<Start-tag> Content </End-tag>
Nested element
Character data
Reference Entity
CDATA
Comment

34. 1. Nested Element
…
<BOOK>
<TITLE> XML Book </TITLE>
<AUTHOR>Prasit Lee </AUTHOR>
</BOOK>

35. 2. Character Data
…
<TITLE> XML Book </TITLE>
<AUTHOR>Prasit Lee </AUTHOR>
…

36. 3. Entity Reference
& &amp;
< &lt;
> &gt;
“ &quot;
‘ &apos;

37. XML Example
xmlerror1.xml
<?xml version=“1.0” ?>
<Example>
<Statement>if x < y </Statement>
</Example>
Not XML Well-formed

38. XML Example
xml03.xml
<?xml version=“1.0” ?>
<Example>
<Statement>if x &lt; y </Statement>
</Example>

39. 4. CDATA Section
xml04.xml
<?xml version=“1.0”?>
<Example>
<Statement>
<![CDATA[
if x > y and a < b
]]>
</Statement>
</Example>

40. CDATA
Sometimes, an XML document needs to store large
blocks of text containing the < and > symbols. In
that case, it would be cumbersome to replace all of
the < and > symbols with &lt; and &gt; character
reference, the code itself will be difficult to read
Instead of using character references, you can place
large blocks of text into a CDATA section
A CDATA section is a large block text that the XML
processor interprets only a text
<![CDATA[
Text block
]]>

41. 5. Comment
…
<BOOK>
<!-- This is comment create by “Prasit” 03.02.2012-->
<TITLE> XML Book </TITLE>
<AUTHOR>Prasit Lee </AUTHOR>
</BOOK>