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

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

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

XP 5 Example if choose

XP 6 Comparison operators

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

XP 8 Example from last week

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

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

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

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

XP 13 Example numbering with position numbering with number element

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

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

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

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

XP 18 Example table of contents

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

XP 20 XPath numerical functions

XP 21 XPath string functions

XP 22 XPath operators

XP 23 Example Calculating the average Problem redundant calculation

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

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

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

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

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

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

XP 30 Examples average with variables

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

XP 32 Number format syntax

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

XP 34 Example average with format

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

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

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

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

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

XP 40 Calling named templates Syntax:...

XP 41 Example average with named template

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

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

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

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

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)

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

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

XP 49 Recursive pattern Syntax with :

XP 50 Example ratings with stars

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

XP 52 Recursive statement?

XP 53 What about the name?

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