/*
    * 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.
   */
  /*
   * PortletAction.java
   *
   *
   * $Id: PortletAction.java,v 1.8.2.1 2003/02/24 18:45:42 tkuebler Exp $
   *
   * Created on January 29, 2003, 2:52 PM
   */
  package org.apache.jetspeed.modules.actions.portlets;
  
  import org.apache.jetspeed.portal.Portlet;
  import org.apache.jetspeed.portal.portlets.GenericMVCPortlet;
  import org.apache.jetspeed.util.PortletSessionState;
  import org.apache.turbine.util.RunData;
  import org.apache.velocity.context.Context;
  
  
  
  
  /***
   *
   * Abstract holder for the portlet specific methods required above and
   * beyond the standard turbine action.
   * 
   * Extends the PortletActionEvent, which
   * encapsulates the event handling feature.
   * 
   * @author  tkuebler
   * @author <a href="mailto:weaver@apache.org">Scott T. Weaver</a>
   * @version $Id: PortletAction.java,v 1.8.2.1 2003/02/24 18:45:42 tkuebler Exp $
   * @stereotype moment-interval
   * 
   */
  
  
  /*
   * Note:
   * assumes a templated portlet, maybe should break this up into two classes
   * the portletaction would only have the build*Context methods
   * the templatedportletaction would have the rest
   * skipping this complexity for now since non-templated portlet actions can just
   * extend ActionEvent and forget about the context probably
   */
  public abstract class PortletAction
      extends PortletActionEvent
    {
  
      /*** Creates a new instance of PortletAction */
      public PortletAction()
        {
        }
  
      public void doPerform(RunData data)
                     throws Exception
        {
  
          // assumes a context for the portlet...
          // should check for null and create one
          doPerform(data, getContext(data));
        }
  
      /***
       * You SHOULD override this method and implement it in your
       * action.
       *
       * @param data Turbine information.
       * @param context Context for web pages.
       * @exception Exception, a generic exception.
       */
      public abstract void doPerform(RunData data, Context context)
                              throws Exception;
  
      /***
       * Return the Context
       *
       * @param RunData data
       * @return Context, a context for web pages.
       */
      protected Context getContext(RunData data)
        {
  
          return (Context) data.getTemplateInfo().getTemplateContext("VelocityPortletContext");
        }
  
     /***
      * This method is used when you want to short circuit an Action
      * and change the template that will be executed next.  The TTL
      * for this is a single request.
      *
      * @param data Turbine information.
      * @param template The template that will be executed next.
      */
     public void setTemplate(RunData data, String template)
       {
         setTemplate(data, template, false);
       }
       
     /***
      * This method is used when you want to short circuit an Action
      * and change the template that will be executed next. If
      * the <code>persistent</code> attribute is set to <i>true</i>
      * the template value is stored in the portlet's session state
      * and will be used until a new value has been set, either within 
      * portlet session or within the context.  Regardless of the
      * value of <code>persistent</code>, the context will ALWAYS
      * have the correct "template" attribute set within.
      *
      * @param data Turbine information.
      * @param template The template that will be executed next.
      * @param persistent whether or not to make the template set 
      * persistent for the extent of the portlet session
      * @author <a href="mailto:weaver@apache.org">Scott T. Weaver</a>
      */
 	public void setTemplate(RunData data, String template, boolean persistent)
 	{
 		Portlet portlet = getPortlet(getContext(data));
 
 		if (template != null)
 		{
 			if (persistent)
 			{
 				PortletSessionState.setAttribute(
 					portlet,
 					data,
 					GenericMVCPortlet.TEMPLATE,
 					template);
 			}
 			else
 			{
 				// Make sure there is no ssession residue ;)
 				resetTemplate(data);
 			}
 
 			// Always make the current template is available within the
 			// context.
 			getContext(data).put("template", template);
 		}
 
 	}
 	
 	/***
 	 * Clears the PortletSessionState of the <code>template</code>
 	 * attribute.
 	 */
 	protected void resetTemplate(RunData data)
 	{
 		Portlet portlet = getPortlet(getContext(data));
 		PortletSessionState.clearAttribute(portlet, data, GenericMVCPortlet.PORTLET);
 	}
       
   
       
     public Portlet getPortlet(Context context)
     {
     	return (Portlet) context.get(GenericMVCPortlet.PORTLET);
     }
     /***
      * Retrieves the template for this PortletAction's Portlet.
 	 * The Portlet <code>init()</code> will have already initialized
 	 * the template value within the current context in this order:<br/>
 	 * 1. From the PortletSessionState's "template" attribute <br />
 	 * 2. From the PortletConfig's "template" parameter.<br /><br />
 	 * However, the action may have overriden this value using
 	 * any of the <code>setTemplate()</code> methods.
      * @param Context context the context for this action's portlet.
      * @return String  Current view template for this action's portlet.
      * @author <a href="mailto:weaver@apache.org">Scott T. Weaver</a>
      */
 	public String getTemplate(Context context)
 	{		
 
 		return (String) context.get(GenericMVCPortlet.TEMPLATE);
 	}
 
     protected abstract void buildConfigureContext(Portlet portlet, Context context, RunData data)
                                            throws Exception;
 
     protected abstract void buildMaximizedContext(Portlet portlet, Context context, RunData data)
                                            throws Exception;
 
     protected abstract void buildNormalContext(Portlet portlet, Context context, RunData data)
                                         throws Exception;
   }