ASP: Transforming the XML - Page 22
November 18, 2002
The following page (cd_list.asp)
does the trick:
<%@ Language=VBScript %>
<%
Dim oXML, oXSL
Set oXML = CreateObject("MSXML2.DOMDocument")
oXML.load(Server.MapPath("cd_list.xml"))
Set oXSL = CreateObject("MSXML2.DOMDocument")
oXSL.load(Server.MapPath("cd_list.xsl"))
Response.write oXML.transformNode(oXSL)
%>
First we create an XML document object:
Set oXML = CreateObject("MSXML2.DOMDocument")
Then we load the cd_list.xml
into the object:
oXML.load(Server.MapPath("cd_list.xml"))
We do the same for the cd_list.xsl
document, and finally we perform the transformation and write out the result.
PHP: Transforming the XML
Performing an XSL transformation in PHP is relatively straightforward. Once
you have the XSLT extension installed the following script is all it takes
(cd_list.php):
<?php
$xsltHnd = xslt_create();
xslt_set_base($xsltHnd,'file://c:/xml/chapter10/');
$html = xslt_process($xsltHnd, 'cd_list.xml', 'cd_list.xsl');
echo $html;
?>
The first line:
$xsltHnd = xslt_create();
creates a new XSLT processor. The function returns
the XSLT processor resource, which we will use for all our other XSLT functions.
If you are working on a Windows machine and intend to pass external files
to the XSLT functions, you will need to set the base URI so that XPath can
resolve the file names. In the setup I used, the URI is as follows:
xslt_set_base($xsltHnd,'file://c:/xml/chapter10/');
With all the XML and XSL documents residing in C:\xml\chapter10.
xslt_set_base takes
2 arguments – the XSLT processor resource and the URI. Once we have set that,
we can then use the xslt_process
function to perform the transformation.
$html = xslt_process($xsltHnd,
'cd_list.xml',
'cd_list.xsl');
In our example we have passed the function the three arguments – the XSLT
processor resource, the name of the XML file, and the name of the XSL stylesheet.
The result of the transformation is returned and stored in the variable $html.
The xslt_process
function has an additional 3 optional arguments, and it is through these that
we have great versatility in the manner in which we can use the function.
Let's take a look at some of the other ways in which we could have written
this script:
<?php
$xsltHnd = xslt_create();
xslt_set_base($xsltHnd,'file://c:/xml/chapter10/');
xslt_process($xsltHnd, 'cd_list.xml',
'cd_list.xsl','cd_list.html');
?>
In this example we are not returning the result of the transformation into
a variable; instead we are specifying a file name as the fourth argument –
the results will be saved in cd_list.html. Another
way we can use the function is by having our XML and XSL stored in variables:
<?php
$xsltHnd = xslt_create();
$xml = join('',file('cd_list.xml'));
$xsl = join('',file('cd_list.xsl'));
$arguments = array(
'/_xml' => $xml,
'/_xsl' => $xsl
);
$html = xslt_process($xsltHnd, 'arg:/_xml',
'arg:/_xsl',
NULL, $arguments);
echo $html;
?>
In this example, the first thing you'll notice is that we have left out the
line that sets the base URI. Since our data is going to be stored in variables
we will not need to set this. The two lines:
$xml = join('',file('cd_list.xml'));
$xsl = join('',file('cd_list.xsl'));
are simply setting the variables $xml and $xsl
to the contents of the XML and XSL files. The file() function reads a file off disk into an array,
one line per element. The join() function joins array elements with a specified
string.
We then create an associative array, called $arguments, containing $xml and $xsl.
Since we don't want to output to a file, we make the fourth argument NULL. While we are talking about the arguments
to the xslt_process
function, it is worth noting that we can pass it an optional fifth argument,
which is an array of parameters. These parameters can then be accessed in
your XSL document with <xsl:param name="parameter_name">.
Transforming the XML - Page 21
Practical XML for the Web
JSP: Transforming the XML - Page 23
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