This document provides an introduction to XML, including: - What XML is and why it was created as an extensible meta language for describing other languages. - Basic XML rules like tags being case sensitive, elements needing closing tags, and attributes requiring quotation marks. - Differences between XML and HTML in terms of focus, predefined tags, and use for transporting vs displaying data. - Benefits of XML like improved web functionality through custom markup and being a meta language that describes other languages.

1. Introduction to XML

2. What is XML?
 Extensible Markup Language
 Extensible-Not fixed format like HTML
 Meta language - Language for describing other languages
 Enables you to define your own customized markup
 Focus on what the data is
 Simplified version of SGML

3. Why XML?
 Richly structured documents could be used over the web.
 Human readable and also easy to edit/view.
 XML documents are language neutral.
 Platform-independent.

4. Basic XML Rules
 Xml is case sensitive
 All start tags must have end tags
 Elements must be properly nested
 XML declaration is the first statement
 Every document must contain a root element
 Attribute values must have quotation marks
 Certain characters are reserved for parsing

5. Differences between XML and HTML
Extensible Markup Language Hyper Text Markup Language
XML is designed to store the data HTML is designed to display the
data
XML focus on what the data is HTML focus on how data looks
XML allows us to define our own HTML has predefined set of tags
tags
XML is used to transport the data HTML is used to format and
display data

6. XML Benefits
 XML improves the functionality of web technologies through the use
of a more flexible and adaptable means to identify information .
 XML is a Meta language, Language that describes other languages.

7. XML Editors
Xml editor is a markup language editor with added
functionality to facilitate the editing of xml.
Xml editor should be able to
 Add closing tags to your opening tags automatically
 Force you to write valid xml
 Verify your xml against a DTD
 Verify your xml against a Schema
 Color codes your xml syntax

8. Some of the professional xml editors are
 EmEditor
 XML Cook top
 XML Pro
 XML Spy

9. XML Tags
Xml tags are very similar to HTML , The difference is that xml
tags are not pre-defined like HTML
Example
<Composer> is an example for an opening tag, In XML all
opening tags must have closing tags, in this case the closing tag
would look like </Composer>.

10. Prolog
Prolog refers to the information that appears before the start tag
of the document or root element. It includes information that
applies to the document as a whole, such as character encoding,
document structure, and style sheets.
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href=“Book.xsl"?>
<!DOCTYPE catalog SYSTEM "catalog.dtd“>

11. XML Declaration
XML declaration typically appears as the first line in an XML
document. The XML declaration is not required, however, if used it
must be the first line in the document.
XML declaration in the document map consists
Version number
<?xml version="1.0"?>
This is mandatory. Although the number might change for future
versions of XML, 1.0 is the current version.

12. XML Declaration Con.
Encoding declaration
<?xml version="1.0" encoding="UTF-8"?>
This is optional. If used, the encoding declaration must
appear immediately after the version information in the
XML declaration.

13. XML Declaration Con.
Standalone declaration
<?xml version="1.0" encoding="UTF-8" standalone="YES"?>
This is optional. If used, the standalone declaration must appear last
in the XML declaration.

14. XML Syntax Rules
 Tags are case sensitive
 Each document must have a root
 Closing tags are required
 Values must be enclosed in quotation marks
 Elements must be properly nested
 Entities must be declared

15. Tags are Case-Sensitive
<CourseName> is different from<coursename>
<Bad>This is bad XML</bad>

16. XML Documents Must Have a Root
<Root>
<Child>
<Subchild>
</Subchild>
</Child>
</Root>

17. Closing Tags are Required
 This is bad XML<p>
 This is also bad<br>
 <p>This is ok</p>
This is the shortcut for an empty tag<br/>

18. Values Must be in Quotation Marks
<student id=1234>Bad Student!</student>
<student id="1234">Good Student</student>

19. Comments in XML
Comments should not appear on the first line.
The string "--" (double-hyphen) is not allowed (as it is used to
delimit comments), and entities must not be recognized within
comments.
Syntax for writing comments in xml is similar to that of HTML.
<! -- This is a comment -->

20. Elements Must be Properly Nested
<tag1><tag2>Badly nested!</tag1></tag2>
<tag1><tag2>Looks good!</tag2></tag1>

21. Structure of XML

22. Structure of XML con..
<?xml version="1.0"?>
<note>
<To>workshop</To>
<From>Trainer</From>
<Heading>Reminder</Heading>
<Body>Don't forget me this
weekend!</Body>
</note>

23. Types of XML Documents
 Well-formed
 Valid
 Invalid

24. Well Formed XML
Well formed xml document does not need a DTD, but is must
confirm to the xml syntax rules.
Valid XML
Valid documents confirms not only to the syntax, but also to
the DTD.
Invalid XML
Neither it follows xml syntax rules nor DTD.

25. Well-Formed XML
Follows the XML syntax rules
<?xml version="1.0"?>
<course>
<name>Markup Languages</name>
<number>99999</number>
<college>New Generation</college>
<credits>4</credits>
</course>

26. Valid XML
Well-formed XML doc that conforms to a DTD.
<?xml version="1.0"?>
<!DOCTYPE course SYSTEM "courses.dtd">
<course>
<name>Markup Languages</name>
<number>9999-82</number>
<college>New Generation</college>
<credits>4</credits>
</course>

27. Invalid XML
Example
<?xml version="1.0"?>
<course>
<name>Markup Languages</name>
<number type=2>9999-82</number>
<college>New Generation</college>
<credits>4
</course>

28. What is DTD?
DTD (Document Type Definition) describes the structure of one
or more XML documents.
OR
Helps in eliminating errors when creating or editing XML
documents.

29. Building Blocks of DTD
 Elements
 Attributes
 Entities
 PCDATA
 CDATA

30. Declaring Elements in a DTD Cont.
<!ELEMENT name ANY>
Creates an element which can contain both Plain text and tags
<!ELEMENT name (#PCDATA)>
Creates an element which can contain plain text but NOT other
tags
<!ELEMENT name EMPTY>
Creates an empty element

31. Declaring Elements in a DTD Cont.
<!ELEMENT name (child1, child2)>
Creates an element with children which must be present in the
order listed
<!ELEMENT name (child1 | child2)>
Creates an element with options
Either child1 or child2 must appear, but not both.

32. Declaring Elements in a DTD Cont.
<!ELEMENT name (child)?>
Creates an element with a child which must appear zero or one
times
<!ELEMENT name (child)+>
Creates an element with a child which must appear one or more
times
<!ELEMENT name (child)*>
Creates an element with a child which may appear zero or more
times

33. Declaring Attributes in a DTD
General form
<!ATTLIST Target-element name Type Default>
Target-element is the element to which the attribute applies
Name is the attribute name type is what type of data the attribute
contains
Default is whether the item is required

34. Attribute-type can be one of the following
Type Description
CDATA The value is character data
(en1|en2|..) The value must be one from an
enumerated list
ID The value is a unique id
IDREF The value is the id of another
element
IDREFS The value is a list of other ids
NMTOKEN The value is a valid xml name
NMTOKENS The value is a list of valid xml
names
ENTITY The value is an entity
ENTITIES The value is a list of entities
NOTATION The value is a name of a notation
xml The value is a predefined xml
value

35. Default-value can be one of the following
Value Explanation
value The default value of the attribute
#REQUIRED The attribute is required
#IMPLIED The attribute is not required
#FIXED value The attribute value is fixed

36. Example
<?xml version="1.0"?>
<!DOCTYPE Parts [
<!ELEMENT Parts (Title?, Part*)>
<!ELEMENT Title (#PCDATA)>
<!ELEMENT Part (Item, Manufacturer, Model, Cost)+>
<!ATTLIST Parttype (Computer|Auto|Airplane) #IMPLIED>
<!ELEMENT Item (#PCDATA)>
<!ELEMENT Manufacturer (#PCDATA)>
<!ELEMENT Model (#PCDATA)>
<!ELEMENT Cost (#PCDATA)>
]>

37. Example cont..
<Parts>
<Title>Main Heading</Title>
<Part type="Computer">
<Item></Item>
<Manufacture></Manufacture>
<Model></Model>
<Cost></Cost>
</Part>
</Parts>

38. XML-Entities
An entity is a name that represents a special character, additional text or
a file.
There are two kinds of entities
 General entities
 Parameter entities

39. XML Predefined Entities
Entity Name Replacement as Text
&lt; <
&gt; >
&amp; &
&apos; ‘
&quot; “

40. XML-Entities cont..
General entities: Used in the context of documents.
References to general entities start with & and end with;
Parameter entities: Used in a document’s DTD.
References to parameter entities start with % and end with;

41. Example
<?xml version="1.0"?>
<!DOCTYPE Film [
<!ENTITY COM "Comedy">
<!ENTITY SF "Science Fiction">
<!ELEMENT Film (Title+, Genre, Year)>
<!ELEMENT Title (#PCDATA)>
<!ELEMENT Genre (#PCDATA)>
<!ELEMENT Year (#PCDATA)>
]>
<Film>
<Title id="1">Tootsie</Title>
<Genre>&COM;</Genre>
<Year>1982</Year>
<Title Id="2">Jurassic Park</Title>
<Genre>&SF;</Genre>
<Year>1993</Year>
</Film>

42. DTD Classification
 Internal document type definition (DTD)
 External document type definition (DTD)

43. Internal DTD
If a DTD is used only by a single XML document, it can be put directly
in that document.
Syntax
<! DOCTYPE Root-Element [DTD Specification]>

44. Example
<?xml version="1.0"?>
<!DOCTYPE Note [
<!ELEMENT Note (To, From, Heading, Body)>
<!ELEMENT To (#PCDATA)>
<!ELEMENT From (#PCDATA)>
<!ELEMENT Heading (#PCDATA)>
<!ELEMENT Body (#PCDATA)>
]>
<Note>
<To>Data1</To>
<From>Data2</From>
<Heading>Reminder</Heading>
<Body>Don't Forget Me This Weekend</Body>
</Note>

45. External DTD
External DTD is one that resides in a separate document. It refers
saving the DTD as a separate file with extension .dtd and then
referencing the DTD file within the XML document.
Syntax
<! DOCTYPE Root-Element SYSTEM "File-Name">

46. Example
<?xml version="1.0"?>
<!DOCTYPE note SYSTEM "note.dtd">
<note>
<to>Data1</to>
<from>Data2</from>
<heading>Reminder</heading>
<body>Don't forget me this weekend!</body>
</note>
And this is the file "note.dtd" which contains the DTD
<!ELEMENT note (to, from, heading, body)>
<!ELEMENT to (#PCDATA)>
<!ELEMENT from (#PCDATA)>
<!ELEMENT heading (#PCDATA)>
<!ELEMENT body (#PCDATA)>

47. What's wrong with DTD?
 DTD’s use old SGML style definitions
 DTD are not written in XML
 Only defaults for attributes, not for elements
 No support for Namespaces

48. XML Schema
XML definition system developed to replace Document Type
Definitions (DTD)

49. XML schema language specification shall
 Be prepared quickly.
 Be precise, concise, human-readable.

50. Formatting XML using CSS
What is CSS?
 CSS stands for Cascading Style Sheets.
 Styles define how to display (XML,HTML)elements.
 External Style Sheets can save a lot of work.
 External Style Sheets are stored in CSS files.

51. XML and CSS
XML and CSS simplify document creation. CSS, on the other
hand, makes it possible to present that document in a
browser.

52. Example
<?xml version=“1.0”?>
<?xml-stylesheet type="text/CSS" href="tutorials.CSS"?>
<tutorials>
<tutorial>
<name>xml Tutorial</name>
<url>www.testport.com</url>
</tutorial>
<tutorial>
<name>HTML Tutorial</name>
<url>www.Test IT Solutions.com</url>
</tutorial>
</tutorials>

53. CSS File
Tutorials {
Margin: 10px;
Background-color: #ccff00;
Font-family: veranda, Helvetica, sans-serif; }
Name {
Display: block;
Font-weight: bold; }
url {
Display: block;
Color: #636363;
Font-size: small;
Font-style: Italic;
}

54. Formatting XML using XSLT
What is XSLT?
 Stands for XSL Transformations
 Most important part of XSL
 Transforms an XML document into another XML document
 Uses XPath to navigate in xml documents
 W3C Recommendation.

55. How Does it Work?

56. XSLT uses XPath to define parts of the source document that
should match one or more predefined templates. When a
match is found, XSLT will transform the matching part of the
source document into the result document.

57. XML Technologies
What Is XHTML?
 Stands for Extensible Hypertext Markup Language
 Almost identical to HTML 4.01
 Stricter and cleaner version of HTML
 Defined as an XML application
 W3C Recommendation

58. XHTML – Why?
 Combination of HTML and XML
 Consists of all the elements in HTML ,Combined with the
strict syntax of XML

59. What is XSL?
XSL stands for Extensible Style Sheet Language. The World
Wide Web Consortium (W3C) started to develop XSL
because there was a need for an XML-based Style sheet
Language.

60. XSL consists of three parts
 XSLT - A language for transforming XML documents
 XPath – A language for navigating in XML documents
 XSL-FO - A language for formatting XML documents

61. Comparing CSS and XSLT
CSS XSLT
Simple to use, and suitable for Complex to use
simple documents
Can’t reorder, add, delete or Can re order, add, delete
perform operations on elements elements
Uses less memory Uses more memory and
processor power
Does not use XML syntax Follows the XML syntax

62. Other Related Technologies
 CSS - Cascading Style Sheets for display.
 XSL - Extensible Style sheet Language for display.
 XSLT - XSL Transformations.
 Xpath - Allows XML files to include other content.
 Xlink - Allows XML files to link to other XML files.
 Xquery - Allows XML files to query databases.

63. Conclusion
 XML is a self-descriptive language
 XML is a powerful language to describe structure data for
web application
 XML is currently applied in many fields
 Many vendors already supports or will support XML

64. Thank You