trinidad-impl/src/main/java/org/apache/myfaces/trinidadinternal/application/ViewHandlerImpl.java - myfaces-trinidad - Git at Google

 /*
  * 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.trinidadinternal.application;

 import java.io.IOException;
 import java.lang.reflect.Constructor;
 import java.net.URL;
 import java.util.HashMap;
 import java.util.Map;

 import javax.faces.FacesException;
 import javax.faces.application.ProjectStage;
 import javax.faces.application.ViewHandler;
 import javax.faces.application.ViewHandlerWrapper;
 import javax.faces.component.UIViewRoot;
 import javax.faces.context.ExternalContext;
 import javax.faces.context.FacesContext;

 import javax.faces.view.ViewDeclarationLanguage;

 import org.apache.myfaces.trinidad.context.RequestContext;
 import org.apache.myfaces.trinidad.logging.TrinidadLogger;
 import org.apache.myfaces.trinidad.render.ExtendedRenderKitService;
 import org.apache.myfaces.trinidad.util.Service;
 import org.apache.myfaces.trinidad.util.URLUtils;
 import org.apache.myfaces.trinidadinternal.context.RequestContextImpl;
 import org.apache.myfaces.trinidadinternal.context.TrinidadPhaseListener;
 import org.apache.myfaces.trinidadinternal.share.config.Configuration;
 import org.apache.myfaces.trinidadinternal.skin.pregen.SkinPregenerationService;

 /**
  * ViewHandler that adds modification detection to the existing ViewHandler,
  * assuming that the viewId is a valid resource path.
  * <p>
  * And now also supports inserting URLs tokens to preserve PageFlowScope.
  * <p>
  * @version $Name:  $ ($Revision: adfrt/faces/adf-faces-impl/src/main/java/oracle/adfinternal/view/faces/application/ViewHandlerImpl.java#0 $) $Date: 05-jan-2006.13:19:09 $
  * @todo Rename something less generic
  * @todo Support extension mapping (*.faces)
  * @todo The modification detection only works for a single user.  That's
  *   OK for now, because it's intended for use while developing
  */
 public class ViewHandlerImpl extends ViewHandlerWrapper
 {
   static public final String ALTERNATE_VIEW_HANDLER =
     "org.apache.myfaces.trinidad.ALTERNATE_VIEW_HANDLER";

   public ViewHandlerImpl(
     ViewHandler delegate)
   {
     _delegate = delegate;
     _timestamps = new HashMap<String, Long>();
     _skinPregenerationEnabled = SkinPregenerationService.isEnabled();
   }

   public ViewHandler getWrapped()
   {
     return _delegate;
   }


   @Override
   public UIViewRoot createView(FacesContext context, String viewId)
   {
     _checkSkinPregeneration(context, viewId);

     _initIfNeeded(context);

     if (_isTimestampCheckEnabled(context, viewId))
     {
       try
       {
         // Check the timestamp on the physical path
         String path = _getPath(viewId);
         synchronized (_timestamps)
         {
           Long ts = _timestamps.get(path);
           if (ts != _NOT_FOUND)
           {
             URL url = context.getExternalContext().getResource(path);
             Long modified = _getLastModified(url);
             _timestamps.put(path, modified);
           }
         }
       }
       catch (IOException e)
       {
         _LOG.severe(e);
       }
     }

     return super.createView(context, viewId);
   }

   @Override
   public String getActionURL(FacesContext context, String viewId)
   {
     String actionURL = super.getActionURL(context, viewId);
     RequestContext afContext = RequestContext.getCurrentInstance();
     if (afContext != null)
     {
       actionURL = afContext.getPageResolver().encodeActionURI(actionURL);
       actionURL = afContext.getPageFlowScopeProvider().
                      encodeCurrentPageFlowScopeURL(context, actionURL);
     }

     return actionURL;
   }

   @Override
   public String getResourceURL(
     FacesContext context,
     String       path)
   {
     return super.getResourceURL(context, path);
   }


   @Override
   public void renderView(
     FacesContext context,
     UIViewRoot   viewToRender) throws IOException, FacesException
   {
     _initIfNeeded(context);

     // Check whether Trinidad's ViewHandler is registered more than once.
     // This happens when the implementation jar is loaded multiple times.
     Map<String, Object> reqMap = context.getExternalContext().getRequestMap();
     if (reqMap.get(_RENDER_VIEW_MARKER) != null)
     {
       _LOG.warning("DUPLICATE_VIEWHANDLER_REGISTRATION");
     }
     else
     {
       reqMap.put(_RENDER_VIEW_MARKER, Boolean.TRUE);
     }

     // See if there is a possiblity of short-circuiting the current
     // Render Response
     ExtendedRenderKitService service = _getExtendedRenderKitService(context);
     if ((service != null) &&
         service.shortCircuitRenderView(context))
     {
       // Yup, we don't need to do anything
       ;
     }
     else
     {
       try
       {
         if (service != null)
           service.encodeBegin(context);

         super.renderView(context, viewToRender);

         if (service != null)
           service.encodeEnd(context);
       }
       finally
       {
         if (service != null)
           service.encodeFinally(context);
       }
     }

     // Remove the 'marker' from the request map just in case the entire tree is rendered again
     reqMap.remove(_RENDER_VIEW_MARKER);
   }

   @Override
   public UIViewRoot restoreView(
     FacesContext context,
     String       viewId)
   {
     //This code processes a "return" event.  Most of this logic was moved to
     //StateManagerImpl because we ran into a problem with JSF where it didn't
     //set up the JSF mapping properly if we didn't delegate to the default
     //ViewHandler.  There may be other logic associated with the internalView
     //which might need to be moved to the StateManager as well.  This might also
     //be able to be further optimized if all the other logic in this method passes
     //through.
     if(context.getExternalContext().getRequestMap().get(RequestContextImpl.LAUNCH_VIEW) != null)
     {
       return super.restoreView(context, viewId);
     }

     boolean uptodate = true;

     if (_isTimestampCheckEnabled(context, viewId))
     {
       try
       {
         // Check the timestamp on the physical path
         String path = _getPath(viewId);
         synchronized (_timestamps)
         {
           Long ts = _timestamps.get(path);
           if (ts != _NOT_FOUND)
           {
             URL url = context.getExternalContext().getResource(path);
             Long modified = _getLastModified(url);
             if (modified == _NOT_FOUND)
             {
               _timestamps.put(path, _NOT_FOUND);
             }
             else if ((ts == null) ||
                      (modified.longValue() > ts.longValue()))
             {
               _timestamps.put(path, modified);
               if (ts != null)
               {
                 _LOG.fine("View document \"" + path + "\" has been modified, " +
                           "ignoring postback for view \"" + viewId +"\"");
               }
               uptodate = false;
             }
           }
         }
       }
       catch (IOException e)
       {
         _LOG.severe(e);
       }
     }

     if (!uptodate)
     {
       return null;
     }

     UIViewRoot result = super.restoreView(context, viewId);
     // If we've successfully restored a view, then assume that
     // this is a postback request.
     if (result != null)
     {
       TrinidadPhaseListener.markPostback(context);
     }

     return result;
   }

   @Override
   public void writeState(
     FacesContext context) throws IOException
   {
     // After the move of InteralView loading code to the ViewDeclarationFactoryImpl,
     // this class was not supposed to do anything with the InternalViews.
     // Unfortunately, writeState() has not been exposed on ViewDeclarationLanguage,
     // so we have to override this method here. Without an override, JSF save state
     // marker gets written straight to the response

     String viewId = context.getViewRoot().getViewId();
     ViewDeclarationLanguage vdl = getViewDeclarationLanguage(context, viewId);
     if (vdl instanceof InternalViewHandlingStrategy)
     {
       InternalViewHandlingStrategy strategy = (InternalViewHandlingStrategy)vdl;
       if (strategy.__isStateless(context, viewId))
       {
         return;
       }
     }

     ExtendedRenderKitService service = _getExtendedRenderKitService(context);
     if ((service != null) &&
         service.isStateless(context))
       return;

     super.writeState(context);
   }


   synchronized private void _initIfNeeded(FacesContext context)
   {
     if (!_inited)
     {
       _inited = true;
       String alternateViewHandler =
         context.getExternalContext().getInitParameter(ALTERNATE_VIEW_HANDLER);
       if (alternateViewHandler != null)
       {
         ViewHandler viewHandlerInstance = null;
         try
         {
           ClassLoader loader = Thread.currentThread().getContextClassLoader();
           Class<?> c = loader.loadClass(alternateViewHandler);
           try
           {
             Constructor<?> constructor = c.getConstructor(
                new Class[]{ViewHandler.class});
             viewHandlerInstance =
                (ViewHandler) constructor.newInstance(new Object[]{_delegate});
           }
           catch (NoSuchMethodException nsme)
           {
             viewHandlerInstance = (ViewHandler) c.newInstance();
           }
         }
         catch (Exception e)
         {
           _LOG.warning("CANNOT_LOAD_VIEWHANDLER", alternateViewHandler);
           _LOG.warning(e);
         }

         if (viewHandlerInstance != null)
           _delegate = viewHandlerInstance;
       }
     }
   }

   private ExtendedRenderKitService _getExtendedRenderKitService(
     FacesContext context)
   {
     return Service.getService(context.getRenderKit(),
                               ExtendedRenderKitService.class);
   }

   /**
    * Reads org.apache.myfaces.trinidad.CHECK_FILE_MODIFICATION context param and determines if
    * the flag is enabled or not.
    * If the context parameter is not specified, default value used is: "false" for
    * ProjectStage.Production and "true" for all other stages.
    * For InternalViews this method always return "false"
    *
    * @param context
    * @param viewId
    * @return
    */
   private boolean _isTimestampCheckEnabled(FacesContext context, String viewId)
   {
     if (_checkTimestamp == null)
     {
       boolean productionStage = context.isProjectStage(ProjectStage.Production);
       boolean checkTimestamp;
       String checkTimestampContextParam =
         context.getExternalContext().getInitParameter(Configuration.CHECK_TIMESTAMP_PARAM);

       if (checkTimestampContextParam != null)
       {
         checkTimestamp = "true".equals(checkTimestampContextParam);
       }
       else
       {
         // if the CHECK_TIMESTAMP_PARAM parameter has NOT been specified, let us
         // apply the DEFAULT values for the certain Project Stages:
         // -PRODUCTION we want this value to be FALSE;
         // -other stages we use TRUE
         checkTimestamp = !productionStage;
       }

       _checkTimestamp = Boolean.valueOf(checkTimestamp);

       // if Apache MyFaces Trinidad is running in ProjectStage.Production,
       // then CHECK_TIMESTAMP_PARAM should be FALSE, otherwise we generate a WARNING message
       if (productionStage && checkTimestamp)
       {
         _LOG.warning("TIMESTAMP_CHECKING_ENABLED_SHOULDNOT_IN_PRODUCTION",
             Configuration.CHECK_TIMESTAMP_PARAM);
       }
     }

     // Even if _isTimestampCheckEnabled is TRUE, we do not want to perform the check for the InternalViews
     if (_checkTimestamp
           && getViewDeclarationLanguage(context, viewId) instanceof InternalViewHandlingStrategy)
     {
       return false;
     }

     return _checkTimestamp;
   }


   /**
    * Return the physical path of a particular URI
    */
   static private String _getPath(String uri)
   {
     RequestContext afc = RequestContext.getCurrentInstance();
     if (afc != null)
     {
       return afc.getPageResolver().getPhysicalURI(uri);
     }

     // No RequestContext?  Just return the URI
     return uri;
   }


   private Long _getLastModified(URL url) throws IOException
   {
     if (url == null)
       return _NOT_FOUND;

     return Long.valueOf(URLUtils.getLastModified(url));
   }

   // We do not allow random requests into the application when the skin
   // pregeneration service is enabled.  Only skin pregeneration requests
   // are allowed.
   private void _checkSkinPregeneration(FacesContext context, String viewId)
   {
     if (_skinPregenerationEnabled && !SkinPregenerationService.isPregenerationRequest(viewId))
     {
       ExternalContext external = context.getExternalContext();
       String message = _LOG.getMessage("SKIN_PREGEN_ENABLED");
       _LOG.severe(message);
       _sendError(external, message);

       // We don't explicitly short-circuit/exception out.  Calling
       // responseComplete() achieves the same result (ie. prevents
       // subsequent processing/rendering) more gracefully.
       context.responseComplete();
     }
   }

   // Sends a response error to the client
   private static void _sendError(ExternalContext external, String message)
   {
     try
     {
       external.responseSendError(500, message);
     }
     catch (IOException e)
     {
       _LOG.warning(e);
     }
   }

   private Boolean           _checkTimestamp;
   // Mostly final, but see _initIfNeeded()
   private ViewHandler       _delegate;
   private final Map<String, Long> _timestamps;
   private boolean           _inited;

   private final boolean _skinPregenerationEnabled;

   private static final TrinidadLogger _LOG = TrinidadLogger.createTrinidadLogger(ViewHandlerImpl.class);
   private static final Long   _NOT_FOUND = Long.valueOf(0);
   private static final String _RENDER_VIEW_MARKER = "__trRenderViewEntry";
 }
	/*
	* 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.trinidadinternal.application;

	import java.io.IOException;
	import java.lang.reflect.Constructor;
	import java.net.URL;
	import java.util.HashMap;
	import java.util.Map;

	import javax.faces.FacesException;
	import javax.faces.application.ProjectStage;
	import javax.faces.application.ViewHandler;
	import javax.faces.application.ViewHandlerWrapper;
	import javax.faces.component.UIViewRoot;
	import javax.faces.context.ExternalContext;
	import javax.faces.context.FacesContext;

	import javax.faces.view.ViewDeclarationLanguage;

	import org.apache.myfaces.trinidad.context.RequestContext;
	import org.apache.myfaces.trinidad.logging.TrinidadLogger;
	import org.apache.myfaces.trinidad.render.ExtendedRenderKitService;
	import org.apache.myfaces.trinidad.util.Service;
	import org.apache.myfaces.trinidad.util.URLUtils;
	import org.apache.myfaces.trinidadinternal.context.RequestContextImpl;
	import org.apache.myfaces.trinidadinternal.context.TrinidadPhaseListener;
	import org.apache.myfaces.trinidadinternal.share.config.Configuration;
	import org.apache.myfaces.trinidadinternal.skin.pregen.SkinPregenerationService;

	/**
	* ViewHandler that adds modification detection to the existing ViewHandler,
	* assuming that the viewId is a valid resource path.
	* <p>
	* And now also supports inserting URLs tokens to preserve PageFlowScope.
	* <p>
	* @version $Name: $ ($Revision: adfrt/faces/adf-faces-impl/src/main/java/oracle/adfinternal/view/faces/application/ViewHandlerImpl.java#0 $) $Date: 05-jan-2006.13:19:09 $
	* @todo Rename something less generic
	* @todo Support extension mapping (*.faces)
	* @todo The modification detection only works for a single user. That's
	* OK for now, because it's intended for use while developing
	*/
	public class ViewHandlerImpl extends ViewHandlerWrapper
	{
	static public final String ALTERNATE_VIEW_HANDLER =
	"org.apache.myfaces.trinidad.ALTERNATE_VIEW_HANDLER";

	public ViewHandlerImpl(
	ViewHandler delegate)
	{
	_delegate = delegate;
	_timestamps = new HashMap<String, Long>();
	_skinPregenerationEnabled = SkinPregenerationService.isEnabled();
	}

	public ViewHandler getWrapped()
	{
	return _delegate;
	}


	@Override
	public UIViewRoot createView(FacesContext context, String viewId)
	{
	_checkSkinPregeneration(context, viewId);

	_initIfNeeded(context);

	if (_isTimestampCheckEnabled(context, viewId))
	{
	try
	{
	// Check the timestamp on the physical path
	String path = _getPath(viewId);
	synchronized (_timestamps)
	{
	Long ts = _timestamps.get(path);
	if (ts != _NOT_FOUND)
	{
	URL url = context.getExternalContext().getResource(path);
	Long modified = _getLastModified(url);
	_timestamps.put(path, modified);
	}
	}
	}
	catch (IOException e)
	{
	_LOG.severe(e);
	}
	}

	return super.createView(context, viewId);
	}

	@Override
	public String getActionURL(FacesContext context, String viewId)
	{
	String actionURL = super.getActionURL(context, viewId);
	RequestContext afContext = RequestContext.getCurrentInstance();
	if (afContext != null)
	{
	actionURL = afContext.getPageResolver().encodeActionURI(actionURL);
	actionURL = afContext.getPageFlowScopeProvider().
	encodeCurrentPageFlowScopeURL(context, actionURL);
	}

	return actionURL;
	}

	@Override
	public String getResourceURL(
	FacesContext context,
	String path)
	{
	return super.getResourceURL(context, path);
	}


	@Override
	public void renderView(
	FacesContext context,
	UIViewRoot viewToRender) throws IOException, FacesException
	{
	_initIfNeeded(context);

	// Check whether Trinidad's ViewHandler is registered more than once.
	// This happens when the implementation jar is loaded multiple times.
	Map<String, Object> reqMap = context.getExternalContext().getRequestMap();
	if (reqMap.get(_RENDER_VIEW_MARKER) != null)
	{
	_LOG.warning("DUPLICATE_VIEWHANDLER_REGISTRATION");
	}
	else
	{
	reqMap.put(_RENDER_VIEW_MARKER, Boolean.TRUE);
	}

	// See if there is a possiblity of short-circuiting the current
	// Render Response
	ExtendedRenderKitService service = _getExtendedRenderKitService(context);
	if ((service != null) &&
	service.shortCircuitRenderView(context))
	{
	// Yup, we don't need to do anything
	;
	}
	else
	{
	try
	{
	if (service != null)
	service.encodeBegin(context);

	super.renderView(context, viewToRender);

	if (service != null)
	service.encodeEnd(context);
	}
	finally
	{
	if (service != null)
	service.encodeFinally(context);
	}
	}

	// Remove the 'marker' from the request map just in case the entire tree is rendered again
	reqMap.remove(_RENDER_VIEW_MARKER);
	}

	@Override
	public UIViewRoot restoreView(
	FacesContext context,
	String viewId)
	{
	//This code processes a "return" event. Most of this logic was moved to
	//StateManagerImpl because we ran into a problem with JSF where it didn't
	//set up the JSF mapping properly if we didn't delegate to the default
	//ViewHandler. There may be other logic associated with the internalView
	//which might need to be moved to the StateManager as well. This might also
	//be able to be further optimized if all the other logic in this method passes
	//through.
	if(context.getExternalContext().getRequestMap().get(RequestContextImpl.LAUNCH_VIEW) != null)
	{
	return super.restoreView(context, viewId);
	}

	boolean uptodate = true;

	if (_isTimestampCheckEnabled(context, viewId))
	{
	try
	{
	// Check the timestamp on the physical path
	String path = _getPath(viewId);
	synchronized (_timestamps)
	{
	Long ts = _timestamps.get(path);
	if (ts != _NOT_FOUND)
	{
	URL url = context.getExternalContext().getResource(path);
	Long modified = _getLastModified(url);
	if (modified == _NOT_FOUND)
	{
	_timestamps.put(path, _NOT_FOUND);
	}
	else if ((ts == null) \|\|
	(modified.longValue() > ts.longValue()))
	{
	_timestamps.put(path, modified);
	if (ts != null)
	{
	_LOG.fine("View document \"" + path + "\" has been modified, " +
	"ignoring postback for view \"" + viewId +"\"");
	}
	uptodate = false;
	}
	}
	}
	}
	catch (IOException e)
	{
	_LOG.severe(e);
	}
	}

	if (!uptodate)
	{
	return null;
	}

	UIViewRoot result = super.restoreView(context, viewId);
	// If we've successfully restored a view, then assume that
	// this is a postback request.
	if (result != null)
	{
	TrinidadPhaseListener.markPostback(context);
	}

	return result;
	}

	@Override
	public void writeState(
	FacesContext context) throws IOException
	{
	// After the move of InteralView loading code to the ViewDeclarationFactoryImpl,
	// this class was not supposed to do anything with the InternalViews.
	// Unfortunately, writeState() has not been exposed on ViewDeclarationLanguage,
	// so we have to override this method here. Without an override, JSF save state
	// marker gets written straight to the response

	String viewId = context.getViewRoot().getViewId();
	ViewDeclarationLanguage vdl = getViewDeclarationLanguage(context, viewId);
	if (vdl instanceof InternalViewHandlingStrategy)
	{
	InternalViewHandlingStrategy strategy = (InternalViewHandlingStrategy)vdl;
	if (strategy.__isStateless(context, viewId))
	{
	return;
	}
	}

	ExtendedRenderKitService service = _getExtendedRenderKitService(context);
	if ((service != null) &&
	service.isStateless(context))
	return;

	super.writeState(context);
	}


	synchronized private void _initIfNeeded(FacesContext context)
	{
	if (!_inited)
	{
	_inited = true;
	String alternateViewHandler =
	context.getExternalContext().getInitParameter(ALTERNATE_VIEW_HANDLER);
	if (alternateViewHandler != null)
	{
	ViewHandler viewHandlerInstance = null;
	try
	{
	ClassLoader loader = Thread.currentThread().getContextClassLoader();
	Class<?> c = loader.loadClass(alternateViewHandler);
	try
	{
	Constructor<?> constructor = c.getConstructor(
	new Class[]{ViewHandler.class});
	viewHandlerInstance =
	(ViewHandler) constructor.newInstance(new Object[]{_delegate});
	}
	catch (NoSuchMethodException nsme)
	{
	viewHandlerInstance = (ViewHandler) c.newInstance();
	}
	}
	catch (Exception e)
	{
	_LOG.warning("CANNOT_LOAD_VIEWHANDLER", alternateViewHandler);
	_LOG.warning(e);
	}

	if (viewHandlerInstance != null)
	_delegate = viewHandlerInstance;
	}
	}
	}

	private ExtendedRenderKitService _getExtendedRenderKitService(
	FacesContext context)
	{
	return Service.getService(context.getRenderKit(),
	ExtendedRenderKitService.class);
	}

	/**
	* Reads org.apache.myfaces.trinidad.CHECK_FILE_MODIFICATION context param and determines if
	* the flag is enabled or not.
	* If the context parameter is not specified, default value used is: "false" for
	* ProjectStage.Production and "true" for all other stages.
	* For InternalViews this method always return "false"
	*
	* @param context
	* @param viewId
	* @return
	*/
	private boolean _isTimestampCheckEnabled(FacesContext context, String viewId)
	{
	if (_checkTimestamp == null)
	{
	boolean productionStage = context.isProjectStage(ProjectStage.Production);
	boolean checkTimestamp;
	String checkTimestampContextParam =
	context.getExternalContext().getInitParameter(Configuration.CHECK_TIMESTAMP_PARAM);

	if (checkTimestampContextParam != null)
	{
	checkTimestamp = "true".equals(checkTimestampContextParam);
	}
	else
	{
	// if the CHECK_TIMESTAMP_PARAM parameter has NOT been specified, let us
	// apply the DEFAULT values for the certain Project Stages:
	// -PRODUCTION we want this value to be FALSE;
	// -other stages we use TRUE
	checkTimestamp = !productionStage;
	}

	_checkTimestamp = Boolean.valueOf(checkTimestamp);

	// if Apache MyFaces Trinidad is running in ProjectStage.Production,
	// then CHECK_TIMESTAMP_PARAM should be FALSE, otherwise we generate a WARNING message
	if (productionStage && checkTimestamp)
	{
	_LOG.warning("TIMESTAMP_CHECKING_ENABLED_SHOULDNOT_IN_PRODUCTION",
	Configuration.CHECK_TIMESTAMP_PARAM);
	}
	}

	// Even if _isTimestampCheckEnabled is TRUE, we do not want to perform the check for the InternalViews
	if (_checkTimestamp
	&& getViewDeclarationLanguage(context, viewId) instanceof InternalViewHandlingStrategy)
	{
	return false;
	}

	return _checkTimestamp;
	}


	/**
	* Return the physical path of a particular URI
	*/
	static private String _getPath(String uri)
	{
	RequestContext afc = RequestContext.getCurrentInstance();
	if (afc != null)
	{
	return afc.getPageResolver().getPhysicalURI(uri);
	}

	// No RequestContext? Just return the URI
	return uri;
	}


	private Long _getLastModified(URL url) throws IOException
	{
	if (url == null)
	return _NOT_FOUND;

	return Long.valueOf(URLUtils.getLastModified(url));
	}

	// We do not allow random requests into the application when the skin
	// pregeneration service is enabled. Only skin pregeneration requests
	// are allowed.
	private void _checkSkinPregeneration(FacesContext context, String viewId)
	{
	if (_skinPregenerationEnabled && !SkinPregenerationService.isPregenerationRequest(viewId))
	{
	ExternalContext external = context.getExternalContext();
	String message = _LOG.getMessage("SKIN_PREGEN_ENABLED");
	_LOG.severe(message);
	_sendError(external, message);

	// We don't explicitly short-circuit/exception out. Calling
	// responseComplete() achieves the same result (ie. prevents
	// subsequent processing/rendering) more gracefully.
	context.responseComplete();
	}
	}

	// Sends a response error to the client
	private static void _sendError(ExternalContext external, String message)
	{
	try
	{
	external.responseSendError(500, message);
	}
	catch (IOException e)
	{
	_LOG.warning(e);
	}
	}

	private Boolean _checkTimestamp;
	// Mostly final, but see _initIfNeeded()
	private ViewHandler _delegate;
	private final Map<String, Long> _timestamps;
	private boolean _inited;

	private final boolean _skinPregenerationEnabled;

	private static final TrinidadLogger _LOG = TrinidadLogger.createTrinidadLogger(ViewHandlerImpl.class);
	private static final Long _NOT_FOUND = Long.valueOf(0);
	private static final String _RENDER_VIEW_MARKER = "__trRenderViewEntry";
	}