XSLT vs. XQuery

Question

I am new to those two technologies, I sketched their roles in generating an HTML out of raw XML file as I understood in these steps(Please correct me if I was wrong):

1. XML data source (database, RSS, ...)
2. XQuery (Data manipulation FLWR)
3. XSLT (Data representation through templating)
4. The resulting XHTML document to be delivered

I am wondering about the technical details of using them, to be specific, here are the questions:

• How to implement XQuery in a PHP web server (I am using WAMP suite).
• How can I request .xq page (can I do that directly, or should I use a CGI to do that?)
• How can I pass the resulting XML page from XQuery call to XSLT for templating?

Could you give me some pointers the development environment to create a website using these technologies, thanks.

-- Update: I understand now that difference between XQuery and XSLT is a difference in point of view since two different working groups are maintaining them, both will do the job though in different approaches. I am using XSLT only for both data operations and representation, I am implementing structured templating approach which is found here XSLT Abstractions in order to organize the work a little bit.

Answer 1

I have a system that works along the lines you describe. It runs like this;

Inputs

1. The XML data is a plain text file eg. "data.xml".
2. The XSL stylesheet is a plain text file eg. "style.xsl".
3. The xquery is a plain text file eg. "test.xq".
4. An xquery processor is running as a service on port 2409. (More about this below.)

Flow

1. A PHP script eg. "index.php" runs. It contacts the xquery processor like this;

   $xml = file_get_contents("http://localhost:2409/test.xq");

2. The test.xq query is executed by the xquery processor. The test.xq query uses the doc function to load the data;

   declare variable $root := doc("data.xml");

   When test.xq finishes, the result is returned by the xquery processor to index.php.

3. Back in index.php, $xml now contains the result of the test.xq xquery. An XSLT processor is invoked to transform the XML into XHTML. The PHP code is something like;

   $doc = new DOMDocument();
   $doc->loadXML($xml);
   $stylesheet = new DOMDocument();
   $stylesheet->load("style.xsl");
   $processor = new XSLTProcessor();
   $processor->importStylesheet($stylesheet);
   $xhtml = $processor->transformToXML($doc);
   echo $xhtml;
   

The only part of all that which is not achievable using standard components is the xquery processor. I had to write that bit using a Java servlet to invoke the Saxon xquery processor. Both Java and Saxon are free but it still took a lot of learning to get it working.

You can see it working here.

I like this technique because a) it separates logic from presentation and b) it runs fast.