XSLT: How Do We Use It?

Transcription

1 XSLT: How Do We Use It? Nancy Hallberg Nikki Massaro Kauffman 1

2 XSLT: Agenda Introduction & Terminology XSLT Walkthrough Client-Side XSLT/XHTML Server-Side XSLT/XHTML More Creative Server-Side XSLT 2

3 XSLT: Terminology CSS HTML v. XHTML XML XPath XSL XSLT 3

4 XSLT: Alphabet Soup CSS & HTML XML - Extensible Markup Language XSL - Extensible Stylesheet Language XHTML 4

5 XSLT: XPath XPath is a language for finding information in an XML document. XPath is used to navigate through elements and attributes in an XML document. Location paths can be Relative or Absolute. 5

6 XSLT: XPath Parents Children Ancestors Descendents Siblings Attributes 6

7 XSLT: XPath Expanded Syntax /child::contacts/child::contact/child::lastname Abbreviated Syntax /contacts/contact/lastname XPath Abbreviated Syntax / * [ ] //- selects all descendants A path expression is written as a sequence of steps to get from one XML node (the current 'context node') to another node or set of nodes Every location path can be expressed using a straightforward but rather verbose syntax. / - separates location steps. - selects current or context node.. - selects the parent of the context - selects an attribute - selects all [] - select specific Example: //a/@href selects an attribute called href in an a element anywhere in the document tree. 7

8 XSLT: Xpath Examples What do the following indicate? / iddcoursemodel/coursetitleshort coursecontent/lesson/page../lesson[@directory!= lessonshare ] /contacts//phone Nikki compares this to relative paths in HTML. 8

9 XSLT: What is XSLT? Extensible Stylesheet Language Transformation Transforms XML documents into other documents Another XML doc HTML doc PDF file And more. 9

10 XSLT: How Do We Use XSLT? Often used as client-side to cache formatting so only data is downloaded. XML XSL Can transform into PDF, EDI, or other formats. We use it for XHTML page navigation, CSS, DWT,.htaccess, and more Data XHTML 10

11 XSLT: Template Elements apply-templates call-template choose / when / otherwise comment for-each if import include key output param sort stylesheet template value-of variable 11

12 XSLT: <xsl:stylesheet> Defines the root element of a stylesheet. <xsl:stylesheet> or <xsl:transform> Nikki compares this to a class containing functions. One per file. 12

13 XSLT: <xsl:output> Defines the format of the output document. It must be a top-level element. Method attributes are xml, html, text <xsl:output method="html encoding="iso "/> 13

14 XSLT: <xsl:template> An XSLT stylesheet consists of one or more set of rules that are called templates. Each template contains rules to apply when a specified node is matched. The value of the match attribute is an XPath expression. <xsl:template match="/"> Nikki compares this to a function. You can have more than one function on in a file. You can call one function from another and pass parameters. 14

15 XSLT: <xsl:text> Exactly what it sounds like - writes text to the output. Attribute of disable-output-escaping <xsl:text disable-outputescaping="yes"><![cdata[<a name="top" id="top"></a>]]></xsl:text> <!ENTITY sp '<xsl:text> </xsl:text>'> 15

16 XSLT: <xsl:variable> Declares a variable The variable is global if it's declared as a top-level element, and local if it's declared within a template. Once you have set a variable's value, you cannot change or modify that value! <xsl:variable name="titleofpage">course Syllabus</xsl:variable> These are really more like constants. 16

17 XSLT: <xsl:value-of> Extracts the value of an XML element and adds it to the output stream of the transformation. The value of the select attribute is an XPath expression. <xsl:value-of select="iddcoursemodel/coursetitlelong /> &sp;<xsl:value-of select="iddcoursemodel/coursetitlelong" disableoutput-escaping="yes"/> 17

18 XSLT: <xsl:if> Yea! Conditionals. Test is a required attribute. It contains the expression to be evaluated. <xsl:if test="iddcoursemodel/gencourphil"> </xsl:if> <xsl:if test="mi!= ''"></xsl:if> 18

19 XSLT: <xsl:for-each> Selects every element in a specified node set. <xsl:for-each select="iddcoursemodel/gencourphil "> 19

20 XSLT: <xsl:sort> Sorts the output The select attribute indicates what XML element to sort on. <xsl:sort data-type="number" order ="ascending"/> 20

21 XSLT: <xsl:choose> Multiple conditionals Instead of If Then Else or switch case Choose When - Otherwise <xsl:choose> <xsl:when test="objectivestem"> <p><xsl:value-of select="objectivestem /></p> </xsl:when> <xsl:otherwise> <p>upon completion of this course you will:</p> </xsl:otherwise> </xsl:choose> 21

22 XSLT: <xsl:apply-templates> The <xsl:apply-templates> element applies a template to the current element or to the current element's child nodes. Adding a select attribute to the <xsl:applytemplates> element makes it process only the child element that matches the value of the attribute. Using the select attribute can also specify the order in which the child nodes are processed. <xsl:apply-templates select="iddcoursemodel" mode="syllabusoverview"/>&br; Like calling a function. 22

23 XSLT: <xsl:call-template> Templates can be called by name. Calls can be recursive. Be careful of the difference between apply-templates & call-template. <xsl:call-template name="spacer" /> <xsl:apply-templates /> <xsl:template match="iddcoursemodel" name="spacer"> <xsl:text disable-output-escaping="yes"><![cdata[*]]></xsl:text> </xsl:template> Like calling a function. 23

24 XSLT: <xsl:param> Declares a parameter The parameter is global if it's declared as a top-level element, and local if it's declared within a template. To pass a parameter to it from another template, use <xsl:with-param>. <xsl:param name="theme"/> <xsl:with-param name="theme"><xsl:valueof select="$theme"/></xsl:with-param> <xsl:call-template name= spacer > <xsl:with-param name= howmany select= 100 /> </xsl:call-template> <xsl:template match="iddcoursemodel" name="spacer"> <xsl:param name="howmany">1</xsl:param> <xsl:text disable-outputescaping="yes"><![cdata[*]]></xsl:text> <xsl:if test="$howmany > 0"> <xsl:call-template name="spacer"> <xsl:with-param name="howmany" select="$howmany -1" /> </xsl:call-template> </xsl:if> </xsl:template> 24

25 XSLT: <xsl:import> Imports the contents of one style sheet into another. An imported style sheet has lower precedence than the importing style sheet. This element must appear as the first child node of <xsl:stylesheet> or <xsl:transform>. 25

26 XSLT: <xsl:include> The <xsl:include> element is a top-level element that includes the contents of one style sheet into another. An included stylesheet has the same precedence as the including style sheet. This element must appear as a child node of <xsl:stylesheet> or <xsl:transform>. <xsl:include href="xslincludes/pagetitle.xsl"/> 26

27 XSLT: <xsl:key> a top-level element which declares a named key that can be used in the style sheet with the key() function. <xsl:key name="themes" match="theme" use="@name"/> <xsl:for-each select="key('themes', $theme)"><xsl:variable name="dark"><xsl:value-of select="@dark"/></xsl:variable></xsl:fo r-each> 27

28 XSLT: Help Feel free to contact us with questions: Nancy Hallberg, Nikki Massaro Kauffman, Additional resources are available at 28