Presentation is loading. Please wait.

Presentation is loading. Please wait.

XP 1 XSLT II Robin Burke ECT 360. XP 2 Homework #4 Forgot we hadn't covered "choose" becomes extra credit My books.xml didn't include descriptions.

Similar presentations


Presentation on theme: "XP 1 XSLT II Robin Burke ECT 360. XP 2 Homework #4 Forgot we hadn't covered "choose" becomes extra credit My books.xml didn't include descriptions."— Presentation transcript:

1 XP 1 XSLT II Robin Burke ECT 360

2 XP 2 Homework #4 Forgot we hadn't covered "choose" becomes extra credit My books.xml didn't include descriptions

3 XP 3 Outline Conditionals Numbering Functions and operators Variables and parameters Named and recursive templates

4 XP 4 Conditional nodes XSLT supports two kinds of conditional elements: If is only if-then (no else) Choose is more general

5 XP 5 Example if choose

6 XP 6 Comparison operators

7 XP 7 Predicates XPath expressions test for a condition result = set of nodes that fulfill that condition Format elementName[condition]

8 XP 8 Example from last week

9 XP 9 Numbering Issues what is counted? what is the format of the numbering? how are numbers at different places in the tree related?

10 XP 10 Numbering Number nodes using: position() Using position(): Nodes are numbered by position in result document Can be used in conditional statements

11 XP 11 Using Attributes: from=pattern: pattern indicates where numbering should restart format=pattern: pattern indicates number format grouping-size, grouping-separator: indicate how digits are grouped and separator character

12 XP 12 Number element Nodes are numbered according to position in source document More flexibility

13 XP 13 Example numbering with position numbering with number element

14 XP 14 Number element Attributes: value=expression: any XPath expression that evaluates to a number (i.e. position()) count=pattern: specifies which nodes to count level=type: tree level for nodes to count; can be any, single, or multiple

15 XP 15 Numbering, cont’d count attribute indicates what is being counted default = count elements of the same name otherwise = specify an XPath pattern all matching elements included

16 XP 16 Numbering relationships how does the number of one element depend on other elements? Possibilities only depends on immediate siblings single depends on “parent” multiple depends on “cousins” any

17 XP 17 Formatting format type 1, a, A, i, I other punctuation

18 XP 18 Example table of contents

19 XP 19 Internal computations Often performed using XPath sort of like SQL Can perform calculations of nodes selected by an XPath expression XPath functions

20 XP 20 XPath numerical functions

21 XP 21 XPath string functions

22 XP 22 XPath operators

23 XP 23 Example Calculating the average Problem redundant calculation

24 XP 24 Variables Not variable! User-defined name that stores a particular value or object Types: number text string node set boolean result tree fragment

25 XP 25 Using variables Syntax: Example: Names are case-sensitive Value only set once upon declaration Enclose text strings in single-quotes

26 XP 26 Using variables, cont'd Value can be XPath expression Value can be XML fragment Syntax:

27 XP 27 Variable reference Syntax: $variable-name Example: $Months Except Referencing tree fragments: Do not use $variable-name Use to reference value

28 XP 28 Global variables Can be referenced from anywhere within the style sheet Must be declared at the top level of the style sheet, as a direct child of the element Must have a unique variable name Evaluated only once when stylesheet is invoked

29 XP 29 Local variables Referenced only within template Can share name with other local or global variable Reevaluated when template is used

30 XP 30 Examples average with variables

31 XP 31 Number format XPath function format-number Syntax: format-number(value, format) Example: format-number(56823.847, '#,##0.00') displays 56,823.85

32 XP 32 Number format syntax

33 XP 33 Decimal format XSL element for defining number formats Named decimal format passed as argument to format-number

34 XP 34 Example average with format

35 XP 35 Parameters Similar to variables, but: Value can be changed after it is declared Can be set outside of scope Syntax: Example: To reference: $param-name

36 XP 36 External parameters Depends on XSLT processor Some work by appending parameter value to url Command line processors allow external parameter setting: MSXML Saxon

37 XP 37 Template parameters Local in scope Created inside element Used to pass parameters to template

38 XP 38 Idea Called template contains param definitions Calling template place element in element or element Syntax: No error if calling param name does not match template param name

39 XP 39 Named template Template not associated with node set Collection of commands that are accessed from other templates in the style sheet Syntax: XSLT elements

40 XP 40 Calling named templates Syntax:...

41 XP 41 Example average with named template

42 XP 42 Functional programming Functional programming language: Relies on the evaluation of functions and expressions, not sequential execution of commands Different from C family of languages LISP, Scheme, ML

43 XP 43 Templates as functions A template supplies a result fragment incorporated into the final document think of this as substitution function call replaced by result

44 XP 44 Iteration How to handle iteration with templates? stars for ratings Possibilities convert numbers into node sets weird since node sets are supposed to come from the document recursive templates

45 XP 45 Recursion base case when do I stop? recursive case how do I bite off one piece call template again with the rest

46 XP 46 Example Template: star(rating) desired output: # stars = # in rating Base case: rating = 0 output: nothing Recursive case rating > 0 output: * plus result of star (rating-1)

47 XP 47 Example, cont'd star(3) replaced by * star(2) replaced by ** star(1) replaced by *** star(0) ***

48 XP 48 Pseudocode stars (n) if n = 0 return '' else return '*' + stars(n-1)

49 XP 49 Recursive pattern Syntax with :.........

50 XP 50 Example ratings with stars

51 XP 51 Another example "best rated" jeep supplier Finding maximum built into XSLT 2.0

52 XP 52 Recursive statement?

53 XP 53 What about the name?

54 XP 54 Homework #5 Case 1 from Chapter 7 Plus doing it "correctly" with CSS Also 10/27 Schema milestone for final project


Download ppt "XP 1 XSLT II Robin Burke ECT 360. XP 2 Homework #4 Forgot we hadn't covered "choose" becomes extra credit My books.xml didn't include descriptions."

Similar presentations


Ads by Google