XML A Single Entity

1. XML A Single Entity

2. xml a single entity • Objectives: • understand the data model • describe the XML Document • describe the XML Schema • describe the XML Stylsheet (XSL)

3. the data model • Wine • wineID • winery • style • vintage • country • region • cost • price • inventory • description WineStore

4. xml Document • XML - a markup language capable of describing many different kinds of data • primary purpose - to facilitate the sharing of data across different systems • defined in a formal way • allows programs to modify and validate documents without prior knowledge of their form picked out from Wikipedia

5. xml schema • an XML Document • provides a template for an XML Document • governs the structure and content • ensures validity of an XML Document • confidence in data transfer

6. xml Stylesheet • eXtensible Stylesheet Language (XSL) • allows for the structured format of the XML Document to be presented visually • allows for a single XML document to have a variety of display designs

7. xml Document • Prolog (XML Declaration) • Elements • Attributes • Rules to follow • Well-formed XML documents

8. <?xml version="1.0" encoding="UTF-8"?> <wineStore> <wine> <wineID>1</wineID> <winery>Ravenswood</winery> <style>Zinfandel</style> <vintage>2003</vintage> <country>United States</country> <region>Sonoma County, California</region> <cost currency='USdollars'>12.50</cost> <price currency='USdollars'>20.75</price> <inventory>35</inventory> <description>This 2003 Zinfandel has huge, jammy, inky, slightly porty aromas infused with black pepper, vanilla and hints of tar, smoke and coffee blend. A very broad, intense wine with huge fruit, lots of those luscious Dry Creek bing cherry and sweet plum characters.</description> </wine> </wineStore> prolog root element parent element sibling elements child element

9. xml Document - prolog <?xml version="1.0" encoding="UTF-8"?> • basic XML Document: prolog = XML declaration • xml   =   this is an XML document • version="1.0"   =   XML 1.0 is the W3C recommend version • encoding="UTF-8"   =   the character encoding used in the document (UTF 8 corresponds to 8-bit ASCII characters) back

10. xml Document - root element <wineStore> …. </wineStore> • the XML document's major theme • must have exactly one and only one root element • all other elements are contained within the one root element • follows the XML declaration back

11. xml Document - parent element <wine> …. </wine> • any element that contains other elements, child elements • <wineStore> is also a parent element with <wine> as its child element • an element can be a parent element to some elements as well as a child element to another element back

12. xml Document - child element <style> …. </style> • any element that is contained within another element, the parent element • <style> is a child element of <wine> • <winery>, <vintage>, <country>, <price>, etc. are all also child elements of <wine> back

13. xml Document - sibling elements • any elements that share a common parent element • <wineID>, <winery>, <vintage>, <style>, <country>, <region>, <cost>, <price>, <inventory>, and <description> are all sibling elements

14. xml Document - elements <elementName> data </elementName> <elementName attribute=“value” /> (empty tag or empty element) (example: <img src="Belize.gif" />)

15. xml Document - attributes <cost currency='USdollars'>7.50</cost> • aid in modifying the content of a given element • provide additional or required information • contained within the element's opening tag

16. xml Document - Rules well-formed XML - abides by rules of syntax • first line = XML Declaration • root element contains all other elements • every element must have an opening tag and a closing tag • attribute values should have quotation marks around them and no spaces • empty tags or empty elements must have a space and a slash (/) at the end of the tag • Comments in the XML language begin with "<!--" and end with "-->"

17. NetBeans select ‘New Project’

20. select a new XML document right click on the newly created project you can also select file/folder and choose XML => XML document

22. if we had already written an XML schema but, we will first just write an XML Document

23. the start of an XML document - note the .xml extension

24. xml schema • Prolog • Element Declarations • Simple Type • Complex Type • Attribute Declarations • Datatype Declarations • Valid XML documents

25. xml schema • A schema defines: • the structure of the document • the elements • the attributes • the child elements • the order of elements • the names and contents of all elements • the data type for each element

26. xml schema - prolog the XML declaration: <?xml version=“1.0” encoding=“UTF-8”?> the Schema declaration: (from chapter) <xsd:schema xmlns:xsd=http://www.w3.org/2001/XMLSchema elementFormDefault="unqualified“> (from NetBeans) <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:ns="http://xml.netbeans.org/examples/targetNS" targetNamespace="http://xml.netbeans.org/examples/targetNS" xmlns=http://xml.netbeans.org/examples/targetNS elementFormDefault="qualified">

27. xml schema - element declarations • define the elements in the schema • include: • the element name • the element data type (optional) • basic element declaration format: • <xsd:element name="name" type="type">

28. xml schema - element declarations • Two types: • Simple Type • do NOT have Child Elements • do NOT have Attributes • Complex Type • can have Child Elements • can have Attributes

29. xml schema - Complex type - child elements <xsd:element name="wineStore"> <xsd:complexType> <xsd:sequence> <xsd:element name="wine" type="wineDescription" /> </xsd:sequence> </xsd:complexType> </xsd:element>

30. xml schema - Complex type - attributes <xsd:element name="cost" type="xsd:decimal"> <xsd:complexType> <xsd:attribute name="currency" type="xsd:string" /> </xsd:complexType> </xsd:element>

31. minOccurs = "1" maxOccurs="unbounded" Occurrence Indicators: - minOccurs = the minimum number of times an element can occur (here it is 1 time) - maxOccurs = the maximum number of times an element can occur (here it is an unlimited number of times, 'unbounded')

32. xml schema - Reference <wineStore xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xsi:schemaLocation='http://xml.netbeans.org/examples/targetNS file:/ C:/Documents and Settings/Viji Kannan/Desktop/TheWineStore/wineStoreSchema.xsd'> these attributes are added to the root element in the XML document

33. xml stylesheet (xsl) • a means to transform and format the contents of an XML document for display • separates the data and the presentation logic • multiple views of the same data can be created using different stylesheets

34. xml stylesheet (xsl) • node tree – a hierarchical representation of the entire XML document – each node represents a piece of the XML document, such as an element, attribute or some text content • contains predefined “templates” that contain instructions on what to do with the nodes • uses the match attribute to relate XML element nodes to the templates, and transform them into the resulting document.

35. XSL - prolog <?xml version="1.0" encoding="UTF-8"?> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:output method="html"/> • the XML declaration • the stylesheet declaration • the namespace declaration • the output document format

36. XSL - templates • the <xsl:template> element is used to create templates that describe how to display elements and their content • each template within an XSL describes a single node – to identify which node a given template is describing, use the 'match' attribute • <xsl:template> defines the start of a template and contains rules to apply when a specified node is matched