The document discusses the fundamentals of XML including XML document structure, elements, attributes, character data, the XML declaration, document type declaration, and XML content model. It also covers XML rules for structure, namespaces, and the differences between well-formed and valid XML documents.

1. Unit 1
Fundamentals of XML

2. XML Document Structure
• XML declaration
• Document type declaration
• Element data
• Attribute data
• Character data/XML content

3. Xml declaration
Components:
• <?xml
• Version=“1.0”
• Standalone =“yes/no”
• Encoding=“US-ASCII”

4. Document type declaration(DOCTYPE)
• Link to DTD
• General forms:
– <!DOCTYPE NAME SYSTEM “file”>
– <!DOCTYPE NAME []>
– <!DOCTYPE NAME SYSTEM “file” []>

5. Components
• <
• !DOCTYPE
• NAME
• SYSTEM
• “file”
• [
• ]
• >

6. Markup and content
Six kinds of markup in XML document:
• Elements
• Entity references
• Comments
• Processing instruction
• Marked section
• Document Type Definition

7. Elements
• A matched pair of XML tags
<shirt> ….. </shirt>
• Single XML tags with ‘self-closing’/empty
element
<shirt/>
• Nested elements

8. Rules for element name
• Element name can contain letters, numbers,
other characters
• No start with a number or punctuation character
• No white space inbetween words
<this_is_really_long_element_name>
• no name as xml or with colon
• Should be descriptive, not confusing.
• Avoid hyphen(-) and dot(.)

9. Attributes
• Additional information about element
• Eg:
<price currency=“USD”>….</price>
<on_sale start_date=“10.5.2001”/>
• In DTD, attribute can be required, optional, fixed
and enumerated.
• Eg:
<shirt><color>red</color></shirt>
Or <shirt color=“red”/>

10. Entity reference
• Symbols referred by name
• Starts with ampersand and ends with
semicolon.
• Eg: <element> 4 &gt; 2</element>
• Types: internal entity & external entity

11. Comments & PI
• <!-- comments lines -->
• PI(processing Instruction) same as comments.
• Information about how the content should be
processed.
• <?instruction options?>
• PI target
• Eg: <?send message “process completed”?>

12. Marked CDATA section
• Character data/CDATA section
• Instructs parser to ignore all markup like
elements, entity, PI,…
• All passed as string.
• <![CDATA[content]]>

13. DTD
• Validate the documents.
• Well defined rules for document structure and
content.

14. XML content
• Content between the elements
• Can consist any data
• Can be long ie.100MB

15. XML content model
• 3 types: open, closed & mixed.
• Open: can add elements & attributes without
declaration in DTD or XML schema.
• Closed: restricts elements and attributes to
only those that are specified in the DTD or
schema.
• Mixed

16. Handling whitespace
• Character spaces, tabs, linefeeds, and carriage
returns in documents.
• Whitespace is significant is by knowing the
content model of the XML document .
• Mixed-significant
• Open/closed-not significant
• Special attribute:- xml:space with 2
values:perserve/default

18. Rules of XML structure
Rule 1:All XML elements must have a closing tag.
Eg: <markup>This is not valid XML
<markup>Since there is no closing tag.
Rule 2:XML tags are case sensitive.
Eg: <Markup>These two tags are very
different</markup>

19. Rules of XML structure
Rule 3:All XML Elements Must Have Proper
Nesting.
Eg:<oxygen><nitrogen>These tags are
improperly nested</oxygen></nitrogen>
Rule 4: All XML Documents Must Contain a
Single Root Element.

21. Rules of XML structure
Rule 5:Attribute Values Must Be Quoted.
Eg:
<?xml version=1.0?>
<shirt>
<price currency=USD>14.99</price>
</shirt>

22. Rules of XML structure
Rule 6:Attributes May Only Appear Once in the
Same Start Tag
Eg: shirt size=”large” size=”small”>Zippy Tee
</shirt>
Rule 7: Attribute Values Cannot Contain References
to External Entities
Rule 8:All Entities Except amp, lt, gt, apos, and quot
Must Be Declared Before They Are Used
Eg: &amp; , &lt;,&gt;, &apos;, &qout;

24. Well formed and valid document
• a valid XML document is a more strict form of
a well-formed XML document .
• well formed if it follows all the preceding
syntax rules of XML.
• valid XML documents can improve the quality
of document processes.

25. Linking XML document
• Xlink
• Xpointer

26. Namespace
• Method to avoid the name conflict.
• Namespaces use a colon-delimited prefix to
associate external semantics with elements
that can be identified via a Universal
Resource Identifier (URI).

27. Example
• <Customer>
<Name>John Smith</Name>
</Customer>
• <Product>
<Name>Hot Dog Buns</Name>
</Product>

28. Example
• <Customer>
<Name>John Smith</Name>
<Order>
<Product>
<Name>Hot Dog Buns</Name>
</Product>
</Order>
</Customer>

29. Example
• <Customer>
<cust:Name xmlns:cust=”customer-namespace-
URI”>John Smith</cust:Name>
<cust:Order>
<prod:Product xmlns:prod=”product-namespace-
URI”>
<prod:Name >Hot Dog Buns</prod:Name>
</prod:Product>
</cust:Order>
</cust:Customer>

30. Default namespace
• <Customer xmlns=”http://www.eps-
software.com/po”>
<Name>Travis Vandersypen</Name>
<Order>
<Product>
<Name>Hot Dog Buns</Name>
</Product>
</Order>
</Customer>

31. Example
• <po:Customer xmlns:po=”http://www.eps-
software.com/po”>
<po:Name>Travis Vandersypen</po:Name>
<po:Order>
<po:Product>
<po:Name>Hot Dog Buns</po:Name>
</po:Product>
</po:Order>
</po:Customer>

32. Multiple namespaces
<cust:Customer xmlns:cust=”http://www.eps-
software.com/customer”
xmlns:ord=”http://www.eps-software.com/order”>
<cust:Name>Travis Vandersypen</cust:Name>
<ord:Order>
<ord:Product>
<prod:Name xmlns:prod=”product-namespace-
URI”>Hot Dog Buns</ord:Name>
</ord:Product>
</ord:Order>
</cust:Customer>

33. Inheriting
<Customer xmlns=”http://www.eps-
software.com/customer”>
<Name>Travis Vandersypen</Name>
<Order xmlns=”http://www.eps-
software.com/order”>
<Product>
<Name>Hot Dog Buns</Name>
</Product>
</Order>
</Customer>