XML XSLT XPath DOCDocument

This is one of the ways that I create dynamic web pages on the fly with using XML/XSLT with a PHP back-end to update the XML on the fly with data obtained (either from MySQL etc, but in this example it will be hard coded).

To start with I am using the PHP DOMDocument object, which is a very good XML reader and updater that uses the XPath query to obtain nodes(lists) from within the XML document itself. So to start with I first load up the XML file that has the basic outputs defined, which means that if you did not want to insert any data on the fly, you could use this basic one.

    $xmlDoc = new DOMDocument();

and here is the XML file, what it basically is is just a symbols that I have created on the fly to mean something to me, like “title”,”form” so that I know what I kinder should be doing with the data located within them, so as you can probably tell I am about to generate an form filled with data.

	<title>XML/XSLT test</title>

The next this to do, is now that we have read in the XML file, we can use the DOCDocument to either createElement, which we can appendChild to that element of any data that we want to insert on the file, I am using a XPath to find the place where I want to insert the new data, in this case within the root/form/table element of the XML document. Since within the above document we have a row tag which is followed by a td tag, I have to create the same to insert, which is why I am creating a element first of a “row” and then appending a child (the 2 td elements) to that node, which at the end I insert the created row into the document via the xpath result.

// now that you have a XML document loaded, if you wanted to add more to areas, then you are 
// able to, thus changing the output on the fly as such.
	$xpath = new DOMXpath($xmlDoc);
	$nodelist = $xpath->query('/root/form/table');
	$row = $xmlDoc->createElement("row","");
	$row->appendChild($xmlDoc->createElement("td","Created on the fly"));
	$row->appendChild($xmlDoc->createElement("td","Right hand side"));
    $xslDoc = new DOMDocument();

Here is my XSLT file, how it kinder works is within the manor of matching elements from the XML document into the stylesheet (XSLT) so for example means to match from the base node (in this case the node called ROOT), then create some textural output (which is html code) and then pull back from data from the /root/title element from within the XML document with using the , to apply other templates that may match other parts from within the XML document, you use the adaptly named apply-templates 🙂 as

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output method="html" encoding="iso-8859-1" indent="no"/>
<xsl:template match="/">
  <title><xsl:value-of select="/root/title"/></title>
	<xsl:apply-templates select="/root/form"/>
<xsl:template match="/root/form">
	<form action="" method="">
		<xsl:apply-templates select="/root/form/table"/>
		<input type="submit" value="submit"/>
<xsl:template match="/root/form/table">
		<xsl:for-each select="row">
				<xsl:for-each select="td">
					<td><xsl:value-of select="."/></td>

and now all we need to do is to process the XML/XSLT to produce the output, with using the XSLTProcessor class

    $proc = new XSLTProcessor();
    echo $proc->transformToXML($xmlDoc);

The output would be, which has the inserted data “Created on the fly”, it may seem like a allot of hassle to get the output like below, but if you was using a far bigger XML file and XSLT with also creating allot of different pages with the same data, but just inserting different parts into the correct XML area, you can start to see that it will save allot of time and also be a nicely validated document.

<html><title>XML/XSLT test</title><body><form action="" method=""><table>
<tr><td>Created on the fly</td><td>Right hand side</td></tr>
</table><input type="submit" value="submit"></form></body></html>