XSLT. Lecture 38. Robb T. Koether. Mon, Apr 21, Hampden-Sydney College. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

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1 XSLT Lecture 38 Robb T. Koether Hampden-Sydney College Mon, Apr 21, 2014 Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

2 1 XSLT 2 Running XSLT 3 XSLT Files 4 Output Modes 5 XSLT Templates 6 Built-in Matching Rules 7 Applying Templates 8 XML to HTML Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

3 Outline 1 XSLT 2 Running XSLT 3 XSLT Files 4 Output Modes 5 XSLT Templates 6 Built-in Matching Rules 7 Applying Templates 8 XML to HTML Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

4 XSLT XSLT = Extensible Stylesheet Language with Transformations XSLT allows us to process the elements in an XML file. XSLT uses XPath to locate nodes in the XML file. Then it uses XSLT to transform the matching items. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

5 Outline 1 XSLT 2 Running XSLT 3 XSLT Files 4 Output Modes 5 XSLT Templates 6 Built-in Matching Rules 7 Applying Templates 8 XML to HTML Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

6 Running XSLT XSLT Files <?xml-stylesheet type="text/xsl" href="file-name.xsl"?> We can run XSLT by executing the program Transform.exe from Saxon. Or we can embed in the HTML file a reference to the XSLT file to be executed, using the element shown above. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

7 Outline 1 XSLT 2 Running XSLT 3 XSLT Files 4 Output Modes 5 XSLT Templates 6 Built-in Matching Rules 7 Applying Templates 8 XML to HTML Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

8 XSLT Files XSLT Files <?xml version="1.0"?> <xsl:stylesheet version="2.0" xmlns:xsl=" template_rules </xsl:stylesheet> The structure of an.xsl file. Everything is within a stylesheet element. The prefix xsl: refers to the namespace. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

9 Outline 1 XSLT 2 Running XSLT 3 XSLT Files 4 Output Modes 5 XSLT Templates 6 Built-in Matching Rules 7 Applying Templates 8 XML to HTML Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

10 Output Modes Output Modes <xsl:output method="xml"/> <xsl:output method="html"/> <xsl:output method="text"/> There are three possible output modes. xml will prepend <?xml version="1.0" encoding="utf-8"?> html will prepend nothing. text will strip all tags from the output. The default is xml. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

11 XSLT Templates An XSLT Template <xsl:template match="xpath-expression"> template-body </xsl:template> The template-body contains instructions on how to process all nodes matched by the XPath-expression. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

12 Outline 1 XSLT 2 Running XSLT 3 XSLT Files 4 Output Modes 5 XSLT Templates 6 Built-in Matching Rules 7 Applying Templates 8 XML to HTML Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

13 XSLT Templates An XSLT Template <xsl:template match="hello"> <h1> <xsl:value-of select="."/> </h1> </xsl:template> This simple template will match any <hello> element. The body of the template says to Write <h1>. Substitute the value of the <hello> element (same as data() in XPath). Write </h1>. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

14 Template Example A Template Example <?xml version="1.0"?> <hello>hello, World!</hello> Given the above.xml file, the output will be <h1>hello, World!</h1> Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

15 Another Template Example Another Template Exampl <?xml version="1.0"?> <hello> HELLO <world>hello, World!</world> WORLD! </hello> What will be the output from the above.xml file? Then reverse the <hello> to <world> tags and run it again. Then make both tags <hello> tags and run it again. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

16 Outline 1 XSLT 2 Running XSLT 3 XSLT Files 4 Output Modes 5 XSLT Templates 6 Built-in Matching Rules 7 Applying Templates 8 XML to HTML Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

17 Matching Rules Matching Rules <xsl:template match="book/title"> <h1><xsl:value-of select="."/></h1> </xsl:template> This example uses the library-dtd.xml database. This template (Example3.xsl) may not do what we expect. Try it. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

18 The Default Rules The Default Rules <xsl:template <xsl:value-of select="."/> </xsl:template> There are several built-in rules, the main one of which is the above rule. It will match all text (text())and all attributes and output their value. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

19 The Default Rules Replacing Default Rules <xsl:template </xsl:template> To suppress this, we need the above rule. It matches all text and attributes, and then does nothing with them. Add this as the last template and then try the title example again. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

20 More Specific Patterns A More Specific Pattern <xsl:template match="book/title"> <xsl:value-of select="."/> </xsl:template> This example will output the titles only of books. How would we output the titles only of collections? Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

21 Outline 1 XSLT 2 Running XSLT 3 XSLT Files 4 Output Modes 5 XSLT Templates 6 Built-in Matching Rules 7 Applying Templates 8 XML to HTML Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

22 The Context Node The Root Context Node <xsl:template match="/"> : </xsl:template> Typically, we begin by matching the root element. This establishes the context node. All rules in a template are relative to its context node of the XPath expression. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

23 The apply-templates XSLT Element The apply-templates XSLT Element <xsl:template match="context-node"> <xsl:apply-templates nodes /> </xsl:template> The apply-templates element will apply any appropriate templates to the specified nodes. In general, nodes is an XPath expression describing a set of elements. If nodes is blank, then the templates will be applied to all descendant nodes. If nodes is *, then the templates are applied to all child nodes. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26

24 The apply-templates XSLT Element The apply-templates XSLT Element <xsl:template match="book"> <xsl:apply-templates select="author"/> </xsl:template> <xsl:template match="collection"> <xsl:apply-templates select="*"/> </xsl:template> The first template will match all book elements and then apply templates to all author elements that are descendants of the book elements. The second template will match all collection elements and apply templates to all of their child nodes. Explain the output of Example4.xsl. Robb T. Koether (Hampden-Sydney College) XSLT Mon, Apr 21, / 26