We've covered the basics of XML, and now we'll discuss what we can do with the data we have. By transforming XML, we can make our data more presentable to a user. XSL refers to XSL Transformations (XSLT), the Path Language (XPath), and a formatting language, though for this appendix our concentration is on XSLT. XSLT became a W3C Recommendation on November 16, 1999 as XSL Transformations (XSLT) Version 1.0; the latest version became a W3C Recommendation on January 23, 2007 as XSL Transformations (XSLT) Version 2.0 (http://www.w3.org/TR/xslt20/). Browsers currently support XSLT 1.0.
XSLT is used to transform an XML file into another text-based format—often HTML or XHTML, but sometimes plain text or other XML vocabularies.
For example, this XSLT would transform the earlier phone book XML into a piece of XHTML code that the browser could style and view accordingly:
<xsl:template match="/phonebook"> <div> <xsl:for-each select="person"> <div> <xsl:text>Name: </xsl:text><strong><xsl:value-of select="name" /> </strong> </div> <div> <xsl:text>Number: </xsl:text><strong><xsl:value-of select="number" /></strong> </div> </xsl:for-each> </div> </xsl:template>
XSLT developed in several distinct stages to become what it is today. These changes occurred as more developers began to use and understand XML and XSL, and the requirements for its definition needed to change along the way to accommodate ideas:
Proposed in ...