/*
* 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.el.unified;
import java.util.Collections;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.el.ELResolver;
import javax.faces.context.FacesContext;
import javax.faces.el.PropertyResolver;
import javax.faces.el.VariableResolver;
import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.collections.Predicate;
import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFWebConfigParam;
import org.apache.myfaces.config.RuntimeConfig;
import org.apache.myfaces.el.convert.PropertyResolverToELResolver;
import org.apache.myfaces.el.convert.VariableResolverToELResolver;
import org.apache.myfaces.el.unified.resolver.FacesCompositeELResolver.Scope;
import org.apache.myfaces.shared.config.MyfacesConfig;
/**
* @author Mathias Broekelmann (latest modification by $Author: lu4242 $)
* @version $Revision: 1296049 $ $Date: 2012-03-02 04:48:16 +0000 (Fri, 02 Mar 2012) $
*/
@SuppressWarnings("deprecation")
public class ResolverBuilderBase
{
private static final Logger log = Logger.getLogger(ResolverBuilderBase.class.getName());
/**
* Define a custom comparator class used to sort the ELResolvers.
*
* <p>This is useful when it is necessary to put an ELResolver on top of other resolvers. Note set
* this param override the default ordering described by JSF spec section 5.
* </p>
*/
@JSFWebConfigParam(since = "1.2.10, 2.0.2", group="EL",
desc = "The Class of an Comparator<ELResolver> implementation.")
public static final String EL_RESOLVER_COMPARATOR = "org.apache.myfaces.EL_RESOLVER_COMPARATOR";
@JSFWebConfigParam(since = "2.1.0", group="EL",
desc="The Class of an org.apache.commons.collections.Predicate<ELResolver> implementation."
+ "If used and returns true for a ELResolver instance, such resolver will not be installed in "
+ "ELResolvers chain. Use with caution - can break functionality defined in JSF specification "
+ "'ELResolver Instances Provided by Faces'")
public static final String EL_RESOLVER_PREDICATE = "org.apache.myfaces.EL_RESOLVER_PREDICATE";
private final RuntimeConfig _config;
public ResolverBuilderBase(RuntimeConfig config)
{
_config = config;
}
/**
* add the el resolvers from the faces config, the el resolver wrapper for variable resolver, the el resolver
* wrapper for the property resolver and the el resolvers added by
* {@link javax.faces.application.Application#addELResolver(ELResolver)}.
* The resolvers where only added if they are not null
*
* @param resolvers
*/
protected void addFromRuntimeConfig(List<ELResolver> resolvers)
{
if (_config.getFacesConfigElResolvers() != null)
{
for (ELResolver resolver : _config.getFacesConfigElResolvers())
{
resolvers.add(resolver);
}
}
FacesContext facesContext = FacesContext.getCurrentInstance();
if (facesContext == null)
{
// Should not happen, but if by some reason happens,
// initialize as usual.
if (_config.getVariableResolver() != null)
{
resolvers.add(createELResolver(_config.getVariableResolver()));
}
else if (_config.getVariableResolverChainHead() != null)
{
resolvers.add(createELResolver(_config.getVariableResolverChainHead()));
}
if (_config.getPropertyResolver() != null)
{
resolvers.add(createELResolver(_config.getPropertyResolver()));
}
else if (_config.getPropertyResolverChainHead() != null)
{
resolvers.add(createELResolver(_config.getPropertyResolverChainHead()));
}
}
else if (facesContext != null && MyfacesConfig.getCurrentInstance(
facesContext.getExternalContext()).isSupportJSPAndFacesEL())
{
if (_config.getVariableResolver() != null)
{
resolvers.add(createELResolver(_config.getVariableResolver()));
}
else if (_config.getVariableResolverChainHead() != null)
{
resolvers.add(createELResolver(_config.getVariableResolverChainHead()));
}
if (_config.getPropertyResolver() != null)
{
resolvers.add(createELResolver(_config.getPropertyResolver()));
}
else if (_config.getPropertyResolverChainHead() != null)
{
resolvers.add(createELResolver(_config.getPropertyResolverChainHead()));
}
}
if (_config.getApplicationElResolvers() != null)
{
for (ELResolver resolver : _config.getApplicationElResolvers())
{
resolvers.add(resolver);
}
}
}
/**
* Sort the ELResolvers with a custom Comparator provided by the user.
* @param resolvers
* @param scope scope of ELResolvers (Faces,JSP)
* @since 1.2.10, 2.0.2
*/
@SuppressWarnings("unchecked")
protected void sortELResolvers(List<ELResolver> resolvers, Scope scope)
{
if (_config.getELResolverComparator() != null)
{
try
{
// sort the resolvers
Collections.sort(resolvers, _config.getELResolverComparator());
if (log.isLoggable(Level.INFO))
{
log.log(Level.INFO, "Chain of EL resolvers for {0} sorted with: {1} and the result order is {2}",
new Object [] {scope, _config.getELResolverComparator(), resolvers});
}
}
catch (Exception e)
{
log.log(Level.WARNING,
"Could not sort ELResolvers with custom Comparator", e);
}
}
}
/**
* Filters the ELResolvers with a custom Predicate provided by the user.
* @param resolvers list of ELResolvers
* @param scope scope of ELResolvers (Faces,JSP)
* @return Iterable instance of Iterable containing filtered ELResolvers
*/
protected Iterable<ELResolver> filterELResolvers(List<ELResolver> resolvers, Scope scope)
{
Predicate predicate = _config.getELResolverPredicate();
if (predicate != null)
{
try
{
// filter the resolvers
CollectionUtils.filter(resolvers, predicate);
if (log.isLoggable(Level.INFO))
{
log.log(Level.INFO, "Chain of EL resolvers for {0} filtered with: {1} and the result is {2}",
new Object [] {scope, predicate, resolvers});
}
}
catch (Exception e)
{
log.log(Level.WARNING,
"Could not filter ELResolvers with custom Predicate", e);
}
}
return resolvers;
}
protected ELResolver createELResolver(VariableResolver resolver)
{
return new VariableResolverToELResolver(resolver);
}
protected ELResolver createELResolver(PropertyResolver resolver)
{
return new PropertyResolverToELResolver(resolver);
}
}