/*
* Copyright 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.
*/
package org.apache.myfaces.application;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.faces.FacesException;
import javax.faces.application.NavigationHandler;
import javax.faces.application.ViewHandler;
import javax.faces.component.UIViewRoot;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.myfaces.config.RuntimeConfig;
import org.apache.myfaces.config.element.NavigationCase;
import org.apache.myfaces.config.element.NavigationRule;
import org.apache.myfaces.portlet.PortletUtil;
import org.apache.myfaces.shared_impl.util.HashMapUtils;
/**
* @author Thomas Spiegl (latest modification by $Author: mbr $)
* @author Anton Koinov
* @version $Revision: 511498 $ $Date: 2007-02-25 14:03:39 +0100 (So, 25 Feb 2007) $
*/
public class NavigationHandlerImpl
extends NavigationHandler
{
private static final Log log = LogFactory.getLog(NavigationHandlerImpl.class);
private static final String ASTERISK = "*";
private Map<String, List> _navigationCases = null;
private List<String> _wildcardKeys = new ArrayList<String>();
public NavigationHandlerImpl()
{
if (log.isTraceEnabled()) log.trace("New NavigationHandler instance created");
}
public void handleNavigation(FacesContext facesContext, String fromAction, String outcome)
{
if (outcome == null)
{
// stay on current ViewRoot
return;
}
NavigationCase navigationCase = getNavigationCase(facesContext, fromAction, outcome);
if (navigationCase != null)
{
if (log.isTraceEnabled())
{
log.trace("handleNavigation fromAction=" + fromAction + " outcome=" + outcome +
" toViewId =" + navigationCase.getToViewId() +
" redirect=" + navigationCase.isRedirect());
}
if (navigationCase.isRedirect() &&
(!PortletUtil.isPortletRequest(facesContext)))
{ // Spec section 7.4.2 says "redirects not possible" in this case for portlets
ExternalContext externalContext = facesContext.getExternalContext();
ViewHandler viewHandler = facesContext.getApplication().getViewHandler();
String redirectPath = viewHandler.getActionURL(facesContext, navigationCase.getToViewId());
try
{
externalContext.redirect(externalContext.encodeActionURL(redirectPath));
}
catch (IOException e)
{
throw new FacesException(e.getMessage(), e);
}
}
else
{
ViewHandler viewHandler = facesContext.getApplication().getViewHandler();
//create new view
String newViewId = navigationCase.getToViewId();
UIViewRoot viewRoot = viewHandler.createView(facesContext, newViewId);
facesContext.setViewRoot(viewRoot);
facesContext.renderResponse();
}
}
else
{
// no navigationcase found, stay on current ViewRoot
if (log.isTraceEnabled())
{
log.trace("handleNavigation fromAction=" + fromAction + " outcome=" + outcome +
" no matching navigation-case found, staying on current ViewRoot");
}
}
}
/**
* Returns the navigation case that applies for the given action and outcome
*/
public NavigationCase getNavigationCase(FacesContext facesContext, String fromAction, String outcome)
{
String viewId = facesContext.getViewRoot().getViewId();
Map<String, List> casesMap = getNavigationCases(facesContext);
NavigationCase navigationCase = null;
List casesList = casesMap.get(viewId);
if (casesList != null)
{
// Exact match?
navigationCase = calcMatchingNavigationCase(casesList, fromAction, outcome);
}
if (navigationCase == null)
{
// Wildcard match?
List<String> keys = getSortedWildcardKeys();
for (int i = 0, size = keys.size(); i < size; i++)
{
String fromViewId = keys.get(i);
if (fromViewId.length() > 2)
{
String prefix = fromViewId.substring(0, fromViewId.length() - 1);
if (viewId != null && viewId.startsWith(prefix))
{
casesList = casesMap.get(fromViewId);
if (casesList != null)
{
navigationCase = calcMatchingNavigationCase(casesList, fromAction, outcome);
if (navigationCase != null) break;
}
}
}
else
{
casesList = casesMap.get(fromViewId);
if (casesList != null)
{
navigationCase = calcMatchingNavigationCase(casesList, fromAction, outcome);
if (navigationCase != null) break;
}
}
}
}
return navigationCase;
}
/**
* Returns the view ID that would be created for the given action and outcome
*/
public String getViewId(FacesContext context, String fromAction, String outcome)
{
return this.getNavigationCase(context, fromAction, outcome).getToViewId();
}
/**
* TODO
* Invoked by the navigation handler before the new view component is created.
* @param viewId The view ID to be created
* @return The view ID that should be used instead. If null, the view ID passed
* in will be used without modification.
*/
public String beforeNavigation(String viewId)
{
return null;
}
private NavigationCase calcMatchingNavigationCase(List casesList, String actionRef, String outcome)
{
for (int i = 0, size = casesList.size(); i < size; i++)
{
NavigationCase caze = (NavigationCase)casesList.get(i);
String cazeOutcome = caze.getFromOutcome();
String cazeActionRef = caze.getFromAction();
if ((cazeOutcome == null || cazeOutcome.equals(outcome)) &&
(cazeActionRef == null || cazeActionRef.equals(actionRef)))
{
return caze;
}
}
return null;
}
private List<String> getSortedWildcardKeys()
{
return _wildcardKeys;
}
private Map<String, List> getNavigationCases(FacesContext facesContext)
{
ExternalContext externalContext = facesContext.getExternalContext();
RuntimeConfig runtimeConfig = RuntimeConfig.getCurrentInstance(externalContext);
if (_navigationCases == null || runtimeConfig.isNavigationRulesChanged())
{
synchronized(this)
{
if (_navigationCases == null || runtimeConfig.isNavigationRulesChanged())
{
Collection rules = runtimeConfig.getNavigationRules();
int rulesSize = rules.size();
Map<String, List> cases = new HashMap<String, List>(HashMapUtils.calcCapacity(rulesSize));
List<String> wildcardKeys = new ArrayList<String>();
for (Iterator iterator = rules.iterator(); iterator.hasNext();)
{
NavigationRule rule = (NavigationRule) iterator.next();
String fromViewId = rule.getFromViewId();
//specification 7.4.2 footnote 4 - missing fromViewId is allowed:
if (fromViewId == null)
{
fromViewId = ASTERISK;
}
else
{
fromViewId = fromViewId.trim();
}
List list = cases.get(fromViewId);
if (list == null)
{
list = new ArrayList(rule.getNavigationCases());
cases.put(fromViewId, list);
if (fromViewId.endsWith(ASTERISK))
{
wildcardKeys.add(fromViewId);
}
} else {
list.addAll(rule.getNavigationCases());
}
}
Collections.sort(wildcardKeys, new KeyComparator());
synchronized (cases)
{
// We do not really need this sychronization at all, but this
// gives us the peace of mind that some good optimizing compiler
// will not rearrange the execution of the assignment to an
// earlier time, before all init code completes
_navigationCases = cases;
_wildcardKeys = wildcardKeys;
runtimeConfig.setNavigationRulesChanged(false);
}
}
}
}
return _navigationCases;
}
private static final class KeyComparator
implements Comparator
{
public int compare(Object o1, Object o2)
{
return -(((String)o1).compareTo((String)o2));
}
}
}