Built-in template rule for text and attribute nodes

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2.4.5.4 Built-in template rule for comment and processing instruction nodes

This template does nothing. xsl:template match=comment|processing-instruction

2.4.5.5 Built-in template rule for namespace nodes

This template also does nothing. xsl:template match=namespace

2.4.6 Top-Level Elements

To this point, we havent actually talked about our source document or how were going to transform it. Were simply setting up some properties for the transform. There are other elements we can put at the start of our stylesheet. Any element whose parent is the xsl:stylesheet element is called a top-level element. Here is a brief discussion of the other top-level elements: xsl:include and xsl:import These elements refer to another stylesheet. The other stylesheet and all of its contents are included in the current stylesheet. The main difference between xsl:import and xsl:include is that a template, variable, or anything else imported with xsl:import has a lower priority than the things in the current stylesheet. This gives you a mechanism to subclass stylesheets, if you want to think about this from an object-oriented point of view. You can import another stylesheet that contains common templates, but any templates in the importing stylesheet will be used instead of any templates in the imported stylesheet. Another difference is that xsl:import can only appear at the beginning of a stylesheet, while xsl:include can appear anywhere. xsl:strip-space and xsl:preserve-space These elements contain a space-separated list of elements from which whitespace should be removed or preserved in the output. To define these elements globally, use xsl:strip-space elements= or xsl:preserve-space elements= . If we want to specify that whitespace be removed for all elements except for greeting elements and salutation elements, we would add this markup to our stylesheet: xsl:strip-space elements= xsl:preserve-space elements=greeting salutation xsl:key This element defines a key, which is similar to defining an index on a database. Well talk more about the xsl:key element and the key function in Section 5.2 in Chapter 5 . xsl:variable This element defines a variable. Any xsl:variable that appears as a top-level element is global to the entire stylesheet. Variables are discussed extensively in Section 4.5 in Chapter 4 . xsl:param This element defines a parameter. As with xsl:variable , any xsl:param that is a top-level element is global to the entire stylesheet. Parameters are discussed extensively in Section 4.4 in Chapter 4 . page 30 Other stuff More obscure elements that can appear as top-level elements are xsl:decimal- format , xsl:namespace-alias , and xsl:attribute-set . All are discussed in Appendix A .

2.4.7 Other Approaches

One mantra of the Perl community is, Theres more than one way to do it. Thats true with XSLT stylesheets, as well. We could have written our stylesheet like this: xsl:stylesheet xmlns:xsl=http:www.w3.org1999XSLTransform version=1.0 xsl:output method=html xsl:template match= html body xsl:apply-templates select=greeting body html xsl:template xsl:template match=greeting h1 xsl:value-of select=. h1 xsl:template xsl:stylesheet In this version, we put the wrapper elements for the HTML document in the template for the root element. One of the things you should think about as you build your stylesheets is where to put elements like html and body . Lets say our XML document looked like this instead: ?xml version=1.0? greetings greetingHello, Worldgreeting greetingHey, Yallgreeting greetings In this case, we would have to put the html and body elements in the xsl:template for the root element. If they were in the xsl:template for the greeting element, the output document would have multiple html elements, something that isnt valid in an HTML document. Our updated stylesheet would look like this: xsl:stylesheet xmlns:xsl=http:www.w3.org1999XSLTransform version=1.0 xsl:output method=html xsl:template match= html body xsl:apply-templates select=greetingsgreeting body html xsl:template xsl:template match=greeting h1 xsl:value-of select=. h1 xsl:template xsl:stylesheet