/*

  * $Source$

  * $Revision$

  *

  * Copyright (c) 1998, 1999, 2000 Semiotek Inc. All Rights Reserved.

  *

  * This software is the confidential intellectual property of

  * of Semiotek Inc.; it is copyrighted and licensed, not sold.

  * You may use it under the terms of the GNU General Public License,

  * version 2, as published by the Free Software Foundation. If you 

  * do not want to use the GPL, you may still use the software after

  * purchasing a proprietary developers license from Semiotek Inc.

  *

  * This software is provided "as is", with NO WARRANTY, not even the 

  * implied warranties of fitness to purpose, or merchantability. You

  * assume all risks and liabilities associated with its use.

  *

  * See the attached License.html file for details, or contact us

  * by e-mail at info@semiotek.com to get a copy.

  */

 package org.melati.test;

 import java.io.IOException;

 import java.util.Date;

 import javax.servlet.ServletConfig;

 import javax.servlet.ServletException;

 import javax.servlet.http.HttpServlet;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import org.melati.util.MelatiBugMelatiException;

 import org.webmacro.FastWriter;

 import org.webmacro.InitException;

 import org.webmacro.ResourceException;

 import org.webmacro.Template;

 import org.webmacro.WM;

 import org.webmacro.WebMacro;

 import org.webmacro.servlet.WebContext;

 /**

  * This example demonstrates using WebMacro in "standalone" mode. Instead of

  * subclassing from WMServlet you create and maintain your own WebMacro object

  * and you are free to subclass from another servlet. Also, this technique can

  * be used outside the servlet context.

  * <p>

  * The WebMacro master object is initialized when the servlet is initialized and

  * destroyed when the servlet is destroyed. There is some overhead involved in

  * creating the interface so you should prefer not to create one on every

  * request, although it is not too expensive.

  * <p>

  * This servlet can be compiled and installed as an ordinary servlet. You need

  * to ensure that your WebMacro.properties file is properly configured and

  * available on your CLASSPATH. When setting up WebMacro.properties make sure

  * that the TemplatePath is correctly set and that the template used by this

  * servlet, "standalone.wm", is available on that path.

  */

 public class WebmacroStandalone extends HttpServlet {

   private static final long serialVersionUID = 1L;

   /**

    * This is the core WebMacro interface which we use to create Contexts, load

    * Templates, and begin other WebMacro operations.

    */

   private WebMacro _wm = null;

   /**

    * The init() method will be called by your servlet runner whenever it wants

    * to instantiate a new copy of your servlet. We initialize WebMacro here so

    * as to avoid the expense of initializing it on every request.

    */

   public void init(ServletConfig sc) throws ServletException {

     try {

       if (_wm == null) {

         _wm = new WM();

       }

     } catch (InitException e) {

       throw new ServletException("Could not initialize WebMacro: " + e);

     }

   }

   /**

    * It's not strictly necessary to destroy the WebMacro object when you're done

    * with it--garbage collection will eventually get it--but it makes sure the

    * resources get freed. You really ought to do this, since it might be a lot

    * of resources.

    */

   public void destroy() {

     // It could of course be null already, but cheaper to re-null;

     // and you get better test coverage.

    _wm = null;

   }

   /**

    * We only implement the GET method in this servlet.

    * <p>

    * We create a WebContext object, populate it with some data, select a

    * template, and write the output of that template to the output stream. Note

    * that you need to pass the WebContext object to the template in order to

    * write it, you also need an output stream, in this case the

    * HttpServletResponse output stream is used.

    * <p>

    * If you were using WebMacro outside a servlet context you would not be able

    * to construct a WebContext object, since you would not have the

    * HttpServletRequest and HttpServletResponse objects which you need in order

    * to do that. WebContext is a subclass of Context, so outside of a servlet

    * just construct a TemplateContext object. You will obviously lose the

    * ability to talk about servlet specific things in your templates (such as

    * "Cookies") but otherwise it's the same.

    * <p>

    * There are a few exceptions you have to deal with. First, WebMacro may not

    * be able to locate the template you've requested in which case it'll throw a

    * NotFoundException. Second, the template will expect to find certain

    * information in the TemplateContext, and if you fail to provide that

    * information a ContextException will be thrown.

    */

   public void doGet(HttpServletRequest req, HttpServletResponse resp)

       throws IOException {

     String templateName = "org/melati/test/WebmacroStandalone.wm";

     WebContext context = new WebContext(_wm.getBroker(), req, resp);

     // fill up the context with our data

     context.put("Today", new Date());

     context.put("Number", new Long(23));

     // WebContext provides some utilities as well

     String other = context.getForm("other");

     if (other == null) {

       context.put("hello", "Hello again!"); // put this into the hash

     } else {

       context.put("hello", other); // else put this in

     }

     String templateNameFromForm = context.getForm("templateName");

     if (templateNameFromForm != null )

       templateName = templateNameFromForm;

     FastWriter fw = new FastWriter(_wm.getBroker(), resp.getOutputStream(),

         resp.getCharacterEncoding());

     // get the template we intend to execute

     Template template = null;

     try {

       template = _wm.getTemplate(templateName);

     } catch (ResourceException e) {

       fw.write("ERROR!  Could not locate template "

               + templateName

               + ", if you are not using a modified WebMacro.properties then it should be on the CLASSPATH.");

       e.printStackTrace();

       fw.close();

       return;

     }

     try {

       // write the template to the output, using our context

       template.write(fw.getOutputStream(), context);

     } catch (org.webmacro.ContextException e) {

        throw new MelatiBugMelatiException("You have misconfigured WebMacro.", e);

     } finally { 

       fw.close();

     }

   }

 }