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XSLT - On the Client

Posted on 2006-08-29 15:01  FreeSpread  阅读(227)  评论(0)    收藏  举报

If your browser supports it, XSLT can be used to transform the document to XHTML in your browser.

A JavaScript Solution

In the previous chapters we have explained how XSLT can be used to transform a document from XML to XHTML. We did this by adding an XSL style sheet to the XML file and let the browser do the transformation.

Even if this works fine, it is not always desirable to include a style sheet reference in an XML file (e.g. it will not work in a non XSLT aware browser.)

A more versatile solution would be to use a JavaScript to do the transformation.

By using a JavaScript, we can:

  • do browser-specific testing
  • use different style sheets according to browser and user needs

That is the beauty of XSLT! One of the design goals for XSLT was to make it possible to transform data from one format to another, supporting different browsers and different user needs.

XSLT transformation on the client side is bound to be a major part of the browsers work tasks in the future, as we will see a growth in the specialized browser market (Braille, aural browsers, Web printers, handheld devices, etc.)

The XML File and the XSL File

Look at the XML document that you have seen in the previous chapters:

<?xml version="1.0" encoding="ISO-8859-1"?>
            <catalog>
            <cd>
            <title>Empire Burlesque</title>
            <artist>Bob Dylan</artist>
            <country>USA</country>
            <company>Columbia</company>
            <price>10.90</price>
            <year>1985</year>
            </cd>
            .
            .
            .
            </catalog>

And the accompanying XSL style sheet:

<?xml version="1.0" encoding="ISO-8859-1"?>
            <xsl:stylesheet version="1.0"
            xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
            <html>
            <body>
            <h2>My CD Collection</h2>
            <table border="1">
            <tr bgcolor="#9acd32">
            <th align="left">Title</th>
            <th align="left">Artist</th>
            </tr>
            <xsl:for-each select="catalog/cd">
            <tr>
            <td><xsl:value-of select="title" /></td>
            <td><xsl:value-of select="artist" /></td>
            </tr>
            </xsl:for-each>
            </table>
            </body>
            </html>
            </xsl:template>
</xsl:stylesheet>

Notice that the XML file does not have a reference to the XSL file!

IMPORTANT: The above sentence indicates that an XML file could be transformed using many different XSL style sheets!

Transforming XML to XHTML in the Browser

Here is the source code needed to transform the XML file to XHTML on the client:

<html>
            <body>
<script type="text/javascript">
// Load XML
            var xml = new ActiveXObject("Microsoft.XMLDOM")
            xml.async = false
            xml.load("cdcatalog.xml")
// Load XSL
            var xsl = new ActiveXObject("Microsoft.XMLDOM")
            xsl.async = false
            xsl.load("cdcatalog.xsl")
// Transform
            document.write(xml.transformNode(xsl))
</script>
</body>
            </html>

Tip: If you don't know how to write JavaScript, you can study our JavaScript tutorial.
The first block of code creates an instance of the Microsoft XML parser (XMLDOM), and loads the XML file into memory. The second block of code creates another instance of the parser and loads the XSL file into memory. The last line of code transforms the XML document using the XSL document, and displays the result as XHTML in your browser. Nice!