/*

  * 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.ui;

 import java.io.IOException;

 import java.net.URL;

 import java.util.Collection;

 import javax.el.ELException;

 import javax.el.ValueExpression;

 import javax.el.VariableMapper;

 import javax.faces.FacesException;

 import javax.faces.application.ProjectStage;

 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.FaceletException;

 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.shared.util.ClassUtils;

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

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

 import org.apache.myfaces.view.facelets.el.VariableMapperWrapper;

 import org.apache.myfaces.view.facelets.impl.TemplateContextImpl;

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

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

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

 /**

  * The include tag can point at any Facelet which might use the composition tag,

  * component tag, or simply be straight XHTML/XML. It should be noted that the 

  * src path does allow relative path names, but they will always be resolved 

  * against the original Facelet requested. 

  * 

  * The include tag can be used in conjunction with multiple <ui:param/> 

  * tags to pass EL expressions/values to the target page.

  * 

  * @author Jacob Hookom

  * @version $Id$

  */

 @JSFFaceletTag(name="ui:include", bodyContent="JSP")

 public final class IncludeHandler extends TagHandler implements ComponentContainerHandler

 {

     private static final String ERROR_PAGE_INCLUDE_PATH = "javax.faces.error.xhtml";

     private static final String ERROR_FACELET = "META-INF/rsc/myfaces-dev-error-include.xhtml";

     /**

      * A literal or EL expression that specifies the target Facelet that you 

      * would like to include into your document.

      */

     @JSFFaceletAttribute(

             className="javax.el.ValueExpression",

             deferredValueType="java.lang.String",

             required=true)

     private final TagAttribute src;

     private final ParamHandler[] _params;

     /**

      * @param config

      */

     public IncludeHandler(TagConfig config)

     {

         super(config);

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

         Collection<ParamHandler> params = TagHandlerUtils.findNextByType(nextHandler, ParamHandler.class);

         if (!params.isEmpty())

         {

             int i = 0;

             _params = new ParamHandler[params.size()];

             for (ParamHandler handler : params)

             {

                 _params[i++] = handler;

             }

         }

         else

         {

             _params = null;

         }

     }

     /*

      * (non-Javadoc)

      * 

      * @see javax.faces.view.facelets.FaceletHandler#apply(javax.faces.view.facelets.FaceletContext, javax.faces.component.UIComponent)

      */

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

             ELException

     {

         AbstractFaceletContext actx = (AbstractFaceletContext) ctx;

         FaceletCompositionContext fcc = FaceletCompositionContext.getCurrentInstance(ctx);

         String path;

         boolean markInitialState = false;

         String uniqueId = null;

         if (!src.isLiteral())

         {

             uniqueId = actx.generateUniqueFaceletTagId(

                 fcc.startComponentUniqueIdSection(), tagId);

         }

         else if (_params != null)

         {

             uniqueId = actx.generateUniqueFaceletTagId(

                 fcc.generateUniqueComponentId(), tagId);

         }

         if (!src.isLiteral())

         {

             //String uniqueId = fcc.startComponentUniqueIdSection();

             //path = getSrcValue(actx, fcc, parent, uniqueId);

             String restoredPath = (String) ComponentSupport.restoreInitialTagState(ctx, fcc, parent, uniqueId);

             if (restoredPath != null)

             {

                 // If is not restore view phase, the path value should be

                 // evaluated and if is not equals, trigger markInitialState stuff.

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

                 {

                     path = this.src.getValue(ctx);

                     if (path == null || path.length() == 0)

                     {

                         return;

                     }

                     if (!path.equals(restoredPath))

                     {

                         markInitialState = true;

                     }

                 }

                 else

                 {

                     path = restoredPath;

                 }

             }

             else

             {

                 //No state restored, calculate path

                 path = this.src.getValue(ctx);

             }

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

         }

         else

         {

             path = this.src.getValue(ctx);

         }

         try

         {

             if (path == null || path.length() == 0)

             {

                 return;

             }

             VariableMapper orig = ctx.getVariableMapper();

             ctx.setVariableMapper(new VariableMapperWrapper(orig));

             try

             {

                 //Only ui:param could be inside ui:include.

                 //this.nextHandler.apply(ctx, null);

                 URL url = null;

                 boolean oldMarkInitialState = false;

                 Boolean isBuildingInitialState = null;

                 // if we are in ProjectStage Development and the path equals "javax.faces.error.xhtml"

                 // we should include the default error page

                 if (ctx.getFacesContext().isProjectStage(ProjectStage.Development) 

                         && ERROR_PAGE_INCLUDE_PATH.equals(path))

                 {

                     url =ClassUtils.getResource(ERROR_FACELET);

                 }

                 if (markInitialState)

                 {

                     //set markInitialState flag

                     oldMarkInitialState = fcc.isMarkInitialState();

                     fcc.setMarkInitialState(true);

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

                             StateManager.IS_BUILDING_INITIAL_STATE, Boolean.TRUE);

                 }

                 try

                 {

                     if (_params != null)

                     {

                         // ui:include defines a new TemplateContext, but ui:param EL expressions

                         // defined inside should be built before the new context is setup, to

                         // apply then after. The final effect is EL expressions will be resolved

                         // correctly when nested ui:params with the same name or based on other

                         // ui:params are used.

                         String[] names = new String[_params.length];

                         ValueExpression[] values = new ValueExpression[_params.length];

                         for (int i = 0; i < _params.length; i++)

                         {

                             names[i] = _params[i].getName(ctx);

                             values[i] = _params[i].getValue(ctx);

                         }

                         actx.pushTemplateContext(new TemplateContextImpl());

                         for (int i = 0; i < _params.length; i++)

                         {

                             _params[i].apply(ctx, parent, names[i], values[i], uniqueId);

                         }

                     }

                     else

                     {

                         actx.pushTemplateContext(new TemplateContextImpl());

                     }

                     if (url == null)

                     {

                         ctx.includeFacelet(parent, path);

                     }

                     else

                     {

                         ctx.includeFacelet(parent, url);

                     }

                 }

                 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);

                     }

                     actx.popTemplateContext();

                 }

             }

             finally

             {

                 ctx.setVariableMapper(orig);

             }

         }

         finally

         {

             if (!src.isLiteral())

             {

                 fcc.endComponentUniqueIdSection();

                 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);

                 }

             }

         }

     }

 }