/*
    * Copyright 2000-2001,2004 The Apache Software Foundation.
    * 
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * 
    *      http://www.apache.org/licenses/LICENSE-2.0
    * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.jetspeed.modules.parameters; 
  
  // Turbine support
  import org.apache.turbine.util.RunData;
  import org.apache.turbine.services.velocity.TurbineVelocity;
  import org.apache.turbine.services.localization.LocalizationTool;
  // Java stuff
  import java.util.Map;
  
  // jetspeed stuff
  import org.apache.jetspeed.services.TemplateLocator;
  import org.apache.jetspeed.services.logging.JetspeedLogFactoryService;
  import org.apache.jetspeed.services.logging.JetspeedLogger;
  import org.apache.jetspeed.util.template.BaseJetspeedLink;
  
  // Velocity Stuff
  import org.apache.velocity.context.Context;
  
  /***
   * Generic Velocity-based presentation style. The following default objects are put in the context:
   * <UL>
   * <LI>data - rundata object</LI>
   * <LI>name - name of the parameter</LI>
   * <LI>value - current value of the parameter</LI>
   * <LI>parms - map of additional style parameters</LI>
   * </UL>
   * 
   * <P>Supporting Velocity templates should be placed in ${velocity-templates-root}/parameters folder.</p>
   * 
   * <P>It may be used directly with "template" as the only required parameter. This is useful when the
   * no additional objects are needed by the template.</P>
   * 
   * <P>If additional objects need to be put in the context, a new class extending VelocityParameterPresentationStyle
   * should be created. Override buildContext to place custom objects in the Velocity context.</P>
   * 
   * <P>If "template" parameter is not specified, it is assumed that the template name is "classname.vm".</P>
   * 
   * @author <a href="mailto:morciuch@apache.org">Mark Orciuch</a>
   * @version $Id: VelocityParameterPresentationStyle.java,v 1.6 2004/02/23 03:01:20 jford Exp $
   */
  
  public class VelocityParameterPresentationStyle extends ParameterPresentationStyle
  {
  
      /***
       * Static initialization of the logger for this class
       */    
      private static final JetspeedLogger logger = JetspeedLogFactoryService.getLogger(VelocityParameterPresentationStyle.class.getName());     
      
      /***
       * Returns presentation control
       * 
       * @param data - rundata object
       * @param name - parameter name
       * @param value - current parameter value
       * @param parms - additional style parameters
       * @return string
       */
      public String getContent(RunData data, String name, String value, Map parms)
      {
          String result = null;
  
          // create a blank context
          Context context = TurbineVelocity.getContext();
  
          // Put basics in the context
          context.put("data", data);
          context.put("name", name);
          context.put("value", value);
          context.put("parms", parms);
          context.put("events", this.getJavascriptEvents());
          LocalizationTool lt = new LocalizationTool();
          lt.init(data);
          context.put("l10n", lt);
          context.put("jslink", new BaseJetspeedLink(data));
  
          try
          {
              // Add custom objects to the context
              this.buildContext(data, name, value, parms, context);
  
              // Build default template name (classname + .vm)
              String className = this.getClass().getName();
             int pos = className.lastIndexOf(".");
             pos = pos < 0 ? 0 : pos + 1;
             className = className.substring(pos);
 
             // Render the template
             String template = (String) this.getParm("template", className + ".vm");
             String templatePath = TemplateLocator.locateParameterTemplate(data, template);
             result = TurbineVelocity.handleRequest(context, templatePath);
         }
         catch (Exception e)
         {
             logger.error("Exception", e);
             // Fallback to input text box presentation style
             result = "<input type=\"text\" name=\"" + name + "\" value=\"" + value + "\"";
         }
 
         TurbineVelocity.requestFinished(context);       
 
         return result;
 
     }
 
     /***
      * Override this method to put your own objects in the Velocity context
      * 
      * @param data
      * @param name
      * @param value
      * @param parms
      * @param context
      */
     public void buildContext(RunData data, String name, String value, Map parms, Context context)
     {
 
     }
 }