/*
    * 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.impl;
  
  import java.io.IOException;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Set;
  
  import javax.el.ELContext;
  import javax.el.ELException;
  import javax.el.ELResolver;
  import javax.el.ExpressionFactory;
  import javax.el.FunctionMapper;
  import javax.el.ValueExpression;
  import javax.el.VariableMapper;
  import javax.faces.FacesException;
  import javax.faces.application.Resource;
  import javax.faces.component.UIComponent;
  import javax.faces.context.FacesContext;
  import javax.faces.view.facelets.FaceletContext;
  import javax.faces.view.facelets.FaceletException;
  
  import org.apache.myfaces.view.facelets.AbstractFacelet;
  import org.apache.myfaces.view.facelets.AbstractFaceletContext;
  import org.apache.myfaces.view.facelets.ELExpressionCacheMode;
  import org.apache.myfaces.view.facelets.FaceletCompositionContext;
  import org.apache.myfaces.view.facelets.PageContext;
  import org.apache.myfaces.view.facelets.TemplateClient;
  import org.apache.myfaces.view.facelets.TemplateContext;
  import org.apache.myfaces.view.facelets.TemplateManager;
  import org.apache.myfaces.view.facelets.el.DefaultVariableMapper;
  import org.apache.myfaces.view.facelets.el.VariableMapperBase;
  import org.apache.myfaces.view.facelets.tag.jsf.core.AjaxHandler;
  
  /**
   * Default FaceletContext implementation.
   * 
   * A single FaceletContext is used for all Facelets involved in an invocation of
   * {@link org.apache.myfaces.view.facelets.Facelet#apply(FacesContext, UIComponent)
   * Facelet#apply(FacesContext, UIComponent)}. This
   * means that included Facelets are treated the same as the JSP include directive.
   * 
   * @author Jacob Hookom
   * @version $Id$
   */
  final class DefaultFaceletContext extends AbstractFaceletContext
  {
      private final FacesContext _faces;
  
      private final ELContext _ctx;
  
      private final AbstractFacelet _facelet;
      private final List<AbstractFacelet> _faceletHierarchy;
  
      private VariableMapper _varMapper;
      private final DefaultVariableMapper _defaultVarMapper;
      private VariableMapperBase _varMapperBase;
  
      private FunctionMapper _fnMapper;
  
      //private final Map<String, Integer> _ids;
      //private final Map<Integer, Integer> _prefixes;
      private String _prefix;
  
      private StringBuilder _uniqueIdBuilder;
  
      //private final LinkedList<TemplateManager> _clients;
      
      private final FaceletCompositionContext _mctx;
      
      private LinkedList<AjaxHandler> _ajaxHandlerStack;
      
      private final List<TemplateContext> _isolatedTemplateContext;
      
      private int _currentTemplateContext;
      
      private ELExpressionCacheMode _elExpressionCacheMode;
      
     private boolean _isCacheELExpressions;
 
     private final List<PageContext> _isolatedPageContext;
     
     public DefaultFaceletContext(DefaultFaceletContext ctx,
             AbstractFacelet facelet, boolean ccWrap)
     {
         _ctx = ctx._ctx;
         //_ids = ctx._ids;
         //_prefixes = ctx._prefixes;
         //_clients = ctx._clients;
         _faces = ctx._faces;
         _fnMapper = ctx._fnMapper;
         _varMapper = ctx._varMapper;
         _defaultVarMapper = ctx._defaultVarMapper;
         _varMapperBase = ctx._varMapperBase;
         _faceletHierarchy = new ArrayList<AbstractFacelet>(ctx._faceletHierarchy
                 .size() + 1);
         _faceletHierarchy.addAll(ctx._faceletHierarchy);
         _faceletHierarchy.add(facelet);
         _facelet = facelet;
         _mctx = ctx._mctx;
         
         if (ccWrap)
         {
             // Each time a composite component is being applied, a new
             // ajax stack should be created, and f:ajax tags outside the
             // composite component should be ignored.
             _ajaxHandlerStack = null;
         }
         else
         {
             // It is a template include, the current ajax stack should be
             // preserved.
             _ajaxHandlerStack = ctx._ajaxHandlerStack;
         }
         
         // It is not necessary to create a copy of this array, because we always use
         // pushTemplateContext(TemplateContext) / popTemplateContext() and
         // pushCompositeComponentClient(final TemplateClient client) / popCompositeComponentClient()
         // in pairs.
         //_isolatedTemplateContext = new ArrayList<TemplateContext>(ctx._isolatedTemplateContext.size()+1);
         //for (int i = 0; i <= ctx._currentTemplateContext; i++)
         //{
         //    _isolatedTemplateContext.add(ctx._isolatedTemplateContext.get(i));
         //}
         _isolatedTemplateContext = ctx._isolatedTemplateContext;
         _currentTemplateContext = ctx._currentTemplateContext;
         
         _isolatedPageContext = ctx._isolatedPageContext;
         
         _elExpressionCacheMode = ctx._elExpressionCacheMode;
         _isCacheELExpressions = ctx._isCacheELExpressions;
 
     }
 
     public DefaultFaceletContext(FacesContext faces, AbstractFacelet facelet, FaceletCompositionContext mctx)
     {
         _ctx = faces.getELContext();
         //_ids = new HashMap<String, Integer>();
         //_prefixes = new HashMap<Integer, Integer>();
         //_clients = new LinkedList<TemplateManager>();
         _faces = faces;
         _fnMapper = _ctx.getFunctionMapper();
         _varMapper = _ctx.getVariableMapper();
         if (_varMapper == null)
         {
             _defaultVarMapper = new DefaultVariableMapper();
             _varMapper = _defaultVarMapper;
             _varMapperBase = _defaultVarMapper;
         }
         else
         {
             _defaultVarMapper = new DefaultVariableMapper(_varMapper);
             _varMapper = _defaultVarMapper;
             _varMapperBase = _defaultVarMapper;
         }
         
         _faceletHierarchy = new ArrayList<AbstractFacelet>(1);
         _faceletHierarchy.add(facelet);
         _facelet = facelet;
         _mctx = mctx;
         
         _isolatedTemplateContext = new ArrayList<TemplateContext>(1);
         _isolatedTemplateContext.add(new TemplateContextImpl());
         _currentTemplateContext = 0;
         _defaultVarMapper.setTemplateContext(_isolatedTemplateContext.get(_currentTemplateContext));
         
         _isolatedPageContext = new ArrayList<PageContext>(8);
         
         _elExpressionCacheMode = mctx.getELExpressionCacheMode();
         _isCacheELExpressions = !ELExpressionCacheMode.noCache.equals(_elExpressionCacheMode);
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public FacesContext getFacesContext()
     {
         return _faces;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public ExpressionFactory getExpressionFactory()
     {
         return _facelet.getExpressionFactory();
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void setVariableMapper(VariableMapper varMapper)
     {
         // Assert.param("varMapper", varMapper);
         _varMapper = varMapper;
         _varMapperBase = (_varMapper instanceof VariableMapperBase) ? (VariableMapperBase) varMapper : null;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void setFunctionMapper(FunctionMapper fnMapper)
     {
         // Assert.param("fnMapper", fnMapper);
         _fnMapper = fnMapper;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void includeFacelet(UIComponent parent, String relativePath)
             throws IOException
     {
         _facelet.include(this, parent, relativePath);
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public FunctionMapper getFunctionMapper()
     {
         return _fnMapper;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public VariableMapper getVariableMapper()
     {
         return _varMapper;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     @SuppressWarnings("unchecked")
     public Object getContext(Class key)
     {
         return _ctx.getContext(key);
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     @SuppressWarnings("unchecked")
     public void putContext(Class key, Object contextObject)
     {
         _ctx.putContext(key, contextObject);
     }
 
     private void initPrefix()
     {
         if (_prefix == null)
         {
             _uniqueIdBuilder = new StringBuilder(
                     _faceletHierarchy.size() * 30);
             for (int i = 0; i < _faceletHierarchy.size(); i++)
             {
                 AbstractFacelet facelet = _faceletHierarchy.get(i);
                 _uniqueIdBuilder.append(facelet.getFaceletId());
             }
 
             // Integer prefixInt = new Integer(builder.toString().hashCode());
             // -= Leonardo Uribe =- if the previous formula is used, it is possible that
             // negative values are introduced. The presence of '-' char causes problems
             // with htmlunit 2.4 or lower, so in order to prevent it it is better to use
             // only positive values instead.
             // Take into account CompilationManager.nextTagId() uses Math.abs too.
             _prefix = Integer.toString(Math.abs(_uniqueIdBuilder.toString().hashCode()));
         }
     }
     
     /**
      * {@inheritDoc}
      */
     @Override
     public String generateUniqueId(String base)
     {
         initPrefix();
 
         _uniqueIdBuilder.setLength(0);
         // getFaceletCompositionContext().generateUniqueId() is the one who ensures
         // the final id will be unique, but prefix and base ensure it will be unique
         // per facelet because prefix is calculated from faceletHierarchy and base is
         // related to the tagId, which depends on the location.
         //_uniqueIdBuilder.append(getFaceletCompositionContext().generateUniqueId());
         
         String uniqueIdFromIterator = getFaceletCompositionContext().getUniqueIdFromIterator();
         if (uniqueIdFromIterator == null)
         {
             getFaceletCompositionContext().generateUniqueId(_uniqueIdBuilder);
             // Since two different facelets are used to build the metadata, it is necessary
             // to trim the "base" part from the returned unique id, to ensure the components will be
             // refreshed properly. Note the "base" part is the one that allows to ensure
             // uniqueness between two different facelets with the same <f:metadata>, but since by 
             // spec view metadata sections cannot live on template client facelets, this case is
             // just not possible. 
             // MYFACES-3709 It was also noticed that in some cases, the prefix should also
             // be excluded from the id. The prefix is included if the metadata section is
             // applied inside an included section (by ui:define and ui:insert for example).
             if (!getFaceletCompositionContext().isInMetadataSection())
             {
                 _uniqueIdBuilder.append("_");
                 _uniqueIdBuilder.append(_prefix);
                 _uniqueIdBuilder.append("_");
                 _uniqueIdBuilder.append(base);
             }
             uniqueIdFromIterator = _uniqueIdBuilder.toString();
             getFaceletCompositionContext().addUniqueId(uniqueIdFromIterator);
             return uniqueIdFromIterator;
         }
         else
         {
             getFaceletCompositionContext().incrementUniqueId();
             return uniqueIdFromIterator;
         }
     }
     
     public String generateUniqueFaceletTagId(String count, String base)    
     {
         initPrefix();
         _uniqueIdBuilder.setLength(0);
         _uniqueIdBuilder.append(count);
         _uniqueIdBuilder.append("_");
         _uniqueIdBuilder.append(_prefix);
         _uniqueIdBuilder.append("_");
         _uniqueIdBuilder.append(base);
         return _uniqueIdBuilder.toString();
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public Object getAttribute(String name)
     {
         if (_varMapper != null)
         {
             ValueExpression ve = _varMapper.resolveVariable(name);
             if (ve != null)
             {
                 return ve.getValue(this);
             }
         }
         return null;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void setAttribute(String name, Object value)
     {
         if (_varMapper != null)
         {
             if (value == null)
             {
                 _varMapper.setVariable(name, null);
             }
             else
             {
                 _varMapper.setVariable(name, _facelet.getExpressionFactory()
                         .createValueExpression(value, Object.class));
             }
         }
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void includeFacelet(UIComponent parent, URL absolutePath)
             throws IOException, FacesException, ELException
     {
         _facelet.include(this, parent, absolutePath);
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public ELResolver getELResolver()
     {
         return _ctx.getELResolver();
     }
 
     //Begin methods from AbstractFaceletContext
 
     @Override
     public TemplateManager popClient(TemplateClient client)
     {
         //if (!this._clients.isEmpty())
         //{
         //    Iterator<TemplateManager> itr = this._clients.iterator();
         //    while (itr.hasNext())
         //    {
         //        if (itr.next().equals(client))
         //        {
         //            itr.remove();
         //            return;
         //        }
         //    }
         //}
         //throw new IllegalStateException(client + " not found");
         //return _clients.removeFirst();
         return _isolatedTemplateContext.get(_currentTemplateContext).popClient(this);
     }
 
     @Override
     public void pushClient(final TemplateClient client)
     {
         //this._clients.add(0, new TemplateManager(this._facelet, client, true));
         //_clients.addFirst(new TemplateManagerImpl(this._facelet, client, true));
         _isolatedTemplateContext.get(_currentTemplateContext).pushClient(this, this._facelet, client);
     }
 
     public TemplateManager popExtendedClient(TemplateClient client)
     {
         //return _clients.removeLast();
         return _isolatedTemplateContext.get(_currentTemplateContext).popExtendedClient(this);
     }
     
     @Override
     public void extendClient(final TemplateClient client)
     {
         //this._clients.add(new TemplateManager(this._facelet, client, false));
         //_clients.addLast(new TemplateManagerImpl(this._facelet, client, false));
         _isolatedTemplateContext.get(_currentTemplateContext).extendClient(this, this._facelet, client);
     }
 
     @Override
     public boolean includeDefinition(UIComponent parent, String name)
             throws IOException, FaceletException, FacesException, ELException
     {
         //boolean found = false;
         //TemplateManager client;
         //for (int i = 0, size = this._clients.size(); i < size && !found; i++)
         //{
         //    client = ((TemplateManager) this._clients.get(i));
         //    if (client.equals(this._facelet))
         //        continue;
         //    found = client.apply(this, parent, name);
         //}
         //return found;
         return _isolatedTemplateContext.get(_currentTemplateContext).includeDefinition(
                 this, this._facelet, parent, name);
     }
 
     /*
     private final static class TemplateManagerImpl extends TemplateManager implements TemplateClient
     {
         private final DefaultFacelet _owner;
 
         private final TemplateClient _target;
 
         private final boolean _root;
 
         private final Set<String> _names = new HashSet<String>();
 
         public TemplateManagerImpl(DefaultFacelet owner, TemplateClient target,
                 boolean root)
         {
             this._owner = owner;
             this._target = target;
             this._root = root;
         }
 
         public boolean apply(FaceletContext ctx, UIComponent parent, String name)
                 throws IOException, FacesException, FaceletException,
                 ELException
         {
             String testName = (name != null) ? name : "facelets._NULL_DEF_";
             if (this._names.contains(testName))
             {
                 return false;
             }
             else
             {
                 this._names.add(testName);
                 boolean found = false;
                 found = this._target
                         .apply(new DefaultFaceletContext(
                                 (DefaultFaceletContext) ctx, this._owner, false),
                                 parent, name);
                 this._names.remove(testName);
                 return found;
             }
         }
 
         public boolean equals(Object o)
         {
             // System.out.println(this.owner.getAlias() + " == " +
             // ((DefaultFacelet) o).getAlias());
             return this._owner == o || this._target == o;
         }
 
         public boolean isRoot()
         {
             return this._root;
         }
     }*/
 
     /*
     @Override
     public TemplateManager popCompositeComponentClient(boolean cleanClientStack)
     {
         //if (!this._compositeComponentClients.isEmpty())
         //{
             //if (cleanClientStack)
             //{
             //    _clientsStack.get(_currentClientStack).clear();
             //}
             //_currentClientStack--;
             //return this._compositeComponentClients.remove(0);
         //}
         if (_currentTemplateContext > 0)
         {
             TemplateManager tm = _isolatedTemplateContext.get(_currentTemplateContext).getCompositeComponentClient();
             if (cleanClientStack)
             {
                 _isolatedTemplateContext.get(_currentTemplateContext).clear();
             }
             _currentTemplateContext--;
             return tm;
         }
         return null;
     }
     
 
     @Override
     public void pushCompositeComponentClient(final TemplateClient client)
     {
         //this._compositeComponentClients.add(0, new CompositeComponentTemplateManager(this._facelet, client));
         //if (_currentClientStack + 1 <= _clientsStack.size())
         //{
         //    _clientsStack.add(new LinkedList<TemplateManager>());
         //}
         //_currentClientStack++;
         if (_currentTemplateContext + 1 <= _isolatedTemplateContext.size())
         {
             _isolatedTemplateContext.add(new IsolatedTemplateContextImpl());
         }
         _currentTemplateContext++;
         _isolatedTemplateContext.get(_currentTemplateContext).setCompositeComponentClient(
             new CompositeComponentTemplateManager(this._facelet, client));
     }
     
     @Override
     public void pushCompositeComponentClient(final TemplateManager client)
     {
         //this._compositeComponentClients.add(0, client);
         //if (_currentClientStack + 1 < _clientsStack.size())
         //{
         //    _clientsStack.add(new LinkedList<TemplateManager>());
         //}
         //_currentClientStack++;
         if (_currentTemplateContext + 1 < _isolatedTemplateContext.size())
         {
             _isolatedTemplateContext.add(new IsolatedTemplateContextImpl());
         }
         _currentTemplateContext++;
         _isolatedTemplateContext.get(_currentTemplateContext).setCompositeComponentClient(client);
     }*/
     
     @Override
     public void pushCompositeComponentClient(final TemplateClient client)
     {
         TemplateContext itc = new TemplateContextImpl();
         itc.setCompositeComponentClient(
                 new CompositeComponentTemplateManager(this._facelet, client, getPageContext()));
         _isolatedTemplateContext.add(itc);
         _currentTemplateContext++;
         _defaultVarMapper.setTemplateContext(itc);
     }
     
     @Override
     public void popCompositeComponentClient()
     {
         if (_currentTemplateContext > 0)
         {
             _isolatedTemplateContext.remove(_currentTemplateContext);
             _currentTemplateContext--;
             _defaultVarMapper.setTemplateContext(_isolatedTemplateContext.get(_currentTemplateContext));
         }
     }
     
     @Override
     public void pushTemplateContext(TemplateContext client)
     {
         _isolatedTemplateContext.add(client);
         _currentTemplateContext++;
         _defaultVarMapper.setTemplateContext(client);
     }    
 
     
     @Override
     public TemplateContext popTemplateContext()
     {
         if (_currentTemplateContext > 0)
         {
             TemplateContext itc = _isolatedTemplateContext.get(_currentTemplateContext);
             _isolatedTemplateContext.remove(_currentTemplateContext);
             _currentTemplateContext--;
             _defaultVarMapper.setTemplateContext(_isolatedTemplateContext.get(_currentTemplateContext));
             return itc;
         }
         return null;
     }
     
     @Override
     public TemplateContext getTemplateContext()
     {
         return _isolatedTemplateContext.get(_currentTemplateContext);
     }
 
     @Override
     public boolean includeCompositeComponentDefinition(UIComponent parent, String name)
             throws IOException, FaceletException, FacesException, ELException
     {
         //boolean found = false;
         //TemplateManager client;
 
         //for (int i = 0, size = this._compositeComponentClients.size(); i < size && !found; i++)
         //{
         //    client = ((TemplateManager) this._compositeComponentClients.get(i));
         //    if (client.equals(this._facelet))
         //        continue;
         //    found = client.apply(this, parent, name);
         //}
 
         //return found;
         TemplateClient ccClient = _isolatedTemplateContext.get(_currentTemplateContext).getCompositeComponentClient();
         if (ccClient != null)
         {
             return ccClient.apply(this, parent, name);
         }
         return false;
     }
     
     private final static class CompositeComponentTemplateManager extends TemplateManager implements TemplateClient
     {
         private final AbstractFacelet _owner;
 
         protected final TemplateClient _target;
 
         private final Set<String> _names = new HashSet<String>();
         
         private final PageContext _pageContext;
 
         public CompositeComponentTemplateManager(AbstractFacelet owner, TemplateClient target, PageContext pageContext)
         {
             this._owner = owner;
             this._target = target;
             this._pageContext = pageContext;
         }
 
         public boolean apply(FaceletContext ctx, UIComponent parent, String name)
                 throws IOException, FacesException, FaceletException,
                 ELException
         {
             String testName = (name != null) ? name : "facelets._NULL_DEF_";
             if (this._names.contains(testName))
             {
                 return false;
             }
             else
             {
                 this._names.add(testName);
                 boolean found = false;
                 AbstractFaceletContext actx = new DefaultFaceletContext(
                         (DefaultFaceletContext) ctx, this._owner, false);
                 ctx.getFacesContext().getAttributes().put(FaceletContext.FACELET_CONTEXT_KEY, actx);
                 try
                 {
                     actx.pushPageContext(this._pageContext);
                     found = this._target
                             .apply(actx,
                                     parent, name);
                 }
                 finally
                 {
                     actx.popPageContext();
                 }
                 ctx.getFacesContext().getAttributes().put(FaceletContext.FACELET_CONTEXT_KEY, ctx);
                 this._names.remove(testName);
                 return found;
             }
         }
 
         public boolean equals(Object o)
         {
             // System.out.println(this.owner.getAlias() + " == " +
             // ((DefaultFacelet) o).getAlias());
             return this._owner == o || this._target == o;
         }
 
         @Override
         public int hashCode()
         {
             int result = _owner != null ? _owner.hashCode() : 0;
             result = 31 * result + (_target != null ? _target.hashCode() : 0);
             return result;
         }
     }
     
     @Override
     public void pushPageContext(PageContext client)
     {
         _isolatedPageContext.add(client);
         _defaultVarMapper.setPageContext(client);
     }    
 
     @Override
     public PageContext popPageContext()
     {
         if (!_isolatedPageContext.isEmpty())
         {
             int currentPageContext = _isolatedPageContext.size()-1;
             PageContext itc = _isolatedPageContext.get(currentPageContext);
             _isolatedPageContext.remove(currentPageContext);
             if (!_isolatedPageContext.isEmpty())
             {
                 _defaultVarMapper.setPageContext(getPageContext());
             }
             else
             {
                 _defaultVarMapper.setPageContext(null);
             }
             return itc;
         }
         return null;
     }
     
     @Override
     public PageContext getPageContext()
     {
         return _isolatedPageContext.get(_isolatedPageContext.size()-1);
     }
     
     //End methods from AbstractFaceletContext
     
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean isPropertyResolved()
     {
         return _ctx.isPropertyResolved();
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void setPropertyResolved(boolean resolved)
     {
         _ctx.setPropertyResolved(resolved);
     }
 
     @Override
     public void applyCompositeComponent(UIComponent parent, Resource resource)
             throws IOException, FaceletException, FacesException, ELException
     {
         _facelet.applyCompositeComponent(this, parent, resource);
     }
 
     @Override
     public Iterator<AjaxHandler> getAjaxHandlers()
     {
         if (_ajaxHandlerStack != null && !_ajaxHandlerStack.isEmpty())
         {
             return _ajaxHandlerStack.iterator();
         }
         return null;
     }
 
     @Override
     public void popAjaxHandlerToStack()
     {
         if (_ajaxHandlerStack != null && !_ajaxHandlerStack.isEmpty())
         {
             _ajaxHandlerStack.removeFirst();
         }
     }
 
     @Override
     public void pushAjaxHandlerToStack(
             AjaxHandler parent)
     {
         if (_ajaxHandlerStack == null)
         {
             _ajaxHandlerStack = new LinkedList<AjaxHandler>();
         }
 
         _ajaxHandlerStack.addFirst(parent);
     }
 
     @Override
     public boolean isBuildingCompositeComponentMetadata()
     {
         return _facelet.isBuildingCompositeComponentMetadata();
     }
     
     public FaceletCompositionContext getFaceletCompositionContext()
     {
         return _mctx;
     }
     
     public boolean isAnyFaceletsVariableResolved()
     {
         //if (isAllowCacheELExpressions() && _varMapperBase != null)
         if (_varMapperBase != null)
         {
             return _varMapperBase.isAnyFaceletsVariableResolved();
         }
         return true;
     }
     
     public boolean isAllowCacheELExpressions()
     {
         return _isCacheELExpressions && getTemplateContext().isAllowCacheELExpressions() 
                 && getPageContext().isAllowCacheELExpressions();
     }
     
     public void beforeConstructELExpression()
     {
         //if (isAllowCacheELExpressions() && _varMapperBase != null)
         if (_varMapperBase != null)
         {
             _varMapperBase.beforeConstructELExpression();
         }
     }
     
     public void afterConstructELExpression()
     {
         //if (isAllowCacheELExpressions() && _varMapperBase != null)
         if (_varMapperBase != null)
         {
             _varMapperBase.afterConstructELExpression();
         }
     }
     
     public ELExpressionCacheMode getELExpressionCacheMode()
     {
         return _elExpressionCacheMode;
     }
     
 }