/*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you 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.myfaces.view.facelets.tag.jstl.core;

 import java.io.IOException;

 import javax.el.ELException;

 import javax.faces.FacesException;

 import javax.faces.application.StateManager;

 import javax.faces.component.UIComponent;

 import javax.faces.event.PhaseId;

 import javax.faces.view.facelets.FaceletContext;

 import javax.faces.view.facelets.TagAttribute;

 import javax.faces.view.facelets.TagConfig;

 import javax.faces.view.facelets.TagHandler;

 import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFFaceletAttribute;

 import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFFaceletTag;

 import org.apache.myfaces.view.facelets.AbstractFaceletContext;

 import org.apache.myfaces.view.facelets.FaceletCompositionContext;

 import org.apache.myfaces.view.facelets.tag.ComponentContainerHandler;

 import org.apache.myfaces.view.facelets.tag.jsf.ComponentSupport;

 /**

  * Simple conditional tag, which evalutes its body if the

  * supplied condition is true and optionally exposes a Boolean

  * scripting variable representing the evaluation of this condition

  * 

  * @author Jacob Hookom

  * @version $Id$

  */

 @JSFFaceletTag(name="c:if")

 @JSFFaceletAttribute(

         name="scope",

         className="java.lang.String",

         longDescription="Scope for var.")

 public final class IfHandler extends TagHandler implements ComponentContainerHandler

 {

     /**

      * The test condition that determines whether or

      * not the body content should be processed.

      */

     @JSFFaceletAttribute(className="boolean", required=true)

     private final TagAttribute test;

     /**

      * Name of the exported scoped variable for the

      * resulting value of the test condition. The type

      * of the scoped variable is Boolean.  

      */

     @JSFFaceletAttribute(className="java.lang.String")

     private final TagAttribute var;

     /**

      * @param config

      */

     public IfHandler(TagConfig config)

     {

         super(config);

         this.test = this.getRequiredAttribute("test");

         this.var = this.getAttribute("var");

     }

     public void apply(FaceletContext ctx, UIComponent parent) throws IOException, FacesException, ELException

     {

         FaceletCompositionContext fcc = FaceletCompositionContext.getCurrentInstance(ctx);

         AbstractFaceletContext actx = (AbstractFaceletContext) ctx;

         String uniqueId = actx.generateUniqueFaceletTagId(

             fcc.startComponentUniqueIdSection(), tagId);

         Boolean restoredValue = (Boolean) ComponentSupport.restoreInitialTagState(ctx, fcc, parent, uniqueId);

         boolean b = false;

         boolean markInitialState = false;

         try

         {

             if (restoredValue != null)

             {

                 if (!PhaseId.RESTORE_VIEW.equals(ctx.getFacesContext().getCurrentPhaseId()))

                 {

                     b = this.test.getBoolean(ctx);

                     if (!restoredValue.equals(b))

                     {

                         markInitialState = true;

                     }

                 }

                 else

                 {

                     b = restoredValue;

                 }

             }

             else

             {

                 // No state restored, calculate

                 b = this.test.getBoolean(ctx);

             }

             //boolean b = getTestValue(ctx, fcc, parent, uniqueId);

             if (this.var != null)

             {

                 ctx.setAttribute(var.getValue(ctx), Boolean.valueOf(b));

             }

             if (b)

             {

                 boolean oldMarkInitialState = false;

                 Boolean isBuildingInitialState = null;

                 try

                 {

                     if (markInitialState)

                     {

                         //set markInitialState flag

                         oldMarkInitialState = fcc.isMarkInitialState();

                         fcc.setMarkInitialState(true);

                         isBuildingInitialState = (Boolean) ctx.getFacesContext().getAttributes().put(

                                 StateManager.IS_BUILDING_INITIAL_STATE, Boolean.TRUE);

                     }

                     this.nextHandler.apply(ctx, parent);

                 }

                 finally

                 {

                     if (markInitialState)

                     {

                         //unset markInitialState flag

                         if (isBuildingInitialState == null)

                         {

                             ctx.getFacesContext().getAttributes().remove(

                                     StateManager.IS_BUILDING_INITIAL_STATE);

                         }

                         else

                         {

                             ctx.getFacesContext().getAttributes().put(

                                     StateManager.IS_BUILDING_INITIAL_STATE, isBuildingInitialState);

                         }

                         fcc.setMarkInitialState(oldMarkInitialState);

                     }

                 }

             }

         }

         finally

         {

             fcc.endComponentUniqueIdSection();

         }

         //AbstractFaceletContext actx = (AbstractFaceletContext) ctx;

         ComponentSupport.saveInitialTagState(ctx, fcc, parent, uniqueId, b);

         if (fcc.isUsingPSSOnThisView() && fcc.isRefreshTransientBuildOnPSS() && !fcc.isRefreshingTransientBuild())

         {

             //Mark the parent component to be saved and restored fully.

             ComponentSupport.markComponentToRestoreFully(ctx.getFacesContext(), parent);

         }

         if (fcc.isDynamicComponentSection())

         {

             ComponentSupport.markComponentToRefreshDynamically(ctx.getFacesContext(), parent);

         }

     }

 }