xmlc

Hi everyone,
Have you guys used xmlc ? Im starting to take a look at it and Im trying to understand if/how I can use it instead of my JSP but keeping my servlets...

Hi Giselle,
I have used xmlc for a couple of years now and to tell you the truth I am not impressed.
The concept of it seems pretty cool, a unique way of separating data from presentation etc, but in reality unless you are serving up very simple HTML, things become complex very quickly. It also does not scale well and suffers from performance issues.
For those who don't know what xmlc is:
- code up HTML with HTML 4.0 "id" attributes
- compile the HTML using the xmlc compiler into a Java class, the ids, become static members of the class
- from a servlet you then instantiate the above class and use DOM manipulation to produce the dynamic HTML (adding/removing nodes etc)
- and then essensially perform an out.println(document.toString())
So my advice would be to avoid it and stick with servlets/jsps/taglibs, or even go down the servlets/xml/xslt route.

James.

Thanks James, I had a feeeling I was going to hear that.
Unfortunatelly, I was told to prepare this demo that today uses jsps/servlets on xmlc.
So I have to do kind of a migration.
Hope I got this right:
1) Transform my jps on pure htmls
2) compile them with xmlc
3) create servlets for whatever functionalities I had on my jsps
4) call them from the .java files my compilation produced ?

Yep that's pretty much the steps:
here's a simple xmlc example:
- it should compile assuming you have your environment setup (xmlc jars etc)
- also assuming you know how to invoke the xmlc compiler
the html

the servlet

package mypackage.servlets;
import java.io.*;
import java.net.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.*;
import org.w3c.dom.*;
import org.apache.xalan.xslt.*;
import org.enhydra.xml.xmlc.*;
public class CurrentTimePage extends HttpServlet {
    private static final String XMLC_CLASS_NAME = "mypackage.html.CurrentTime";
    public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
        PrintWriter out = response.getWriter();
        response.setContentType("text/html");
        XMLObjectImpl xmlcPage = null;
        try {
            Class xmlcClass = Class.forName(XMLC_CLASS_NAME);
            xmlcPage = (XMLObjectImpl)xmlcClass.newInstance();
            
            // update hostName element
            Element hostName = xmlcPage.getElementById("host_name");
            setText(hostName,request.getServerName());
            
            // get the current date
            String now = (new java.util.Date()).toString();
            
            // update currentTime element
            Element currentTime = xmlcPage.getElementById("current_time");
            setText(currentTime,now);
            
            // send the HTML page to the browser
            out.println(xmlcPage.toDocument());
            
            // clean up
            out.flush();
            out.close();
        } catch (Exception e) {
            throw new ServletException(e);
        }
    }
    private void setText(Element element, String text) {
        try {
            Document document  = element.getOwnerDocument();
            Node node = document.createCDATASection(text) ;
            
            while (element.hasChildNodes()) {
                Node child = element.getFirstChild();
                element.removeChild(child);
            }
    
            element.appendChild(node);
        } catch (NullPointerException e) {
            e.printStackTrace();
        }
    }
}

James.
[ November 11, 2003: Message edited by: James Swan ]

Thanks, I�ll work on it.