XSLT on the Client

From http://www.w3schools.com (Copyright Refsnes Data)

# XSLT - On the Client

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>

View the XML file.

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>

View the XSL file.

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>
    <head>
    <script>
    function loadXMLDoc(fname)
    {
    var xmlDoc;
    // code for IE
    if (window.ActiveXObject)
      {
      xmlDoc=new ActiveXObject("Microsoft.XMLDOM");
      }
    // code for Mozilla, Firefox, Opera, etc.
    else if (document.implementation
    && document.implementation.createDocument)
      {
      xmlDoc=document.implementation.createDocument("","",null);
      }
    else
      {
      alert('Your browser cannot handle this script');
      }
    xmlDoc.async=false;
    xmlDoc.load(fname);
    return(xmlDoc);
    }

    function displayResult()
    {
    xml=loadXMLDoc("cdcatalog.xml");
    xsl=loadXMLDoc("cdcatalog.xsl");
    // code for IE
    if (window.ActiveXObject)
      {
      ex=xml.transformNode(xsl);
      document.getElementById("example").innerHTML=ex;
      }
    // code for Mozilla, Firefox, Opera, etc.
    else if (document.implementation
    && document.implementation.createDocument)
      {
      xsltProcessor=new XSLTProcessor();
      xsltProcessor.importStylesheet(xsl);
      resultDocument = xsltProcessor.transformToFragment(xml,document);
      document.getElementById("example").appendChild(resultDocument);
      }
    }
    </script>
    </head>
    <body id="example" onLoad="displayResult()">
    </body>
    </html>

Tip: If you don't know how to write JavaScript, you can study our JavaScript tutorial.

## Example Explained:

The loadXMLDoc() Function

The loadXMLDoc() function is used to load the XML and XSL files.

It checks what kind of browser the user has and loads the file.

The displayResult() Function

This function is used to display the XML file styled by the XSL file.

- Load XML and XSL file
- Test what kind of browser the user has
- If the user has a browser supporting the ActiveX object:
  - Use the transformNode() method to apply the XSL style sheet to the xml document
  - Set the body of the current document (id="example") to contain the styled xml document
- If the user has a browser that does not support the ActiveX object:
  - Create a new XSLTProcessor object and import the XSL file to it
  - Use the transformToFragment() method to apply the XSL style sheet to the xml document
  - Set the body of the current document (id="example") to contain the styled xml document

Try it yourself.

From http://www.w3schools.com (Copyright Refsnes Data)