/*
* Copyright 2011 <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
*
* 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.ocpsoft.rewrite.faces.config;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import javax.faces.event.PhaseId;
import javax.servlet.http.HttpServletRequest;
import org.ocpsoft.common.pattern.Weighted;
import org.ocpsoft.common.pattern.WeightedComparator;
import org.ocpsoft.rewrite.config.Operation;
import org.ocpsoft.rewrite.context.EvaluationContext;
import org.ocpsoft.rewrite.servlet.config.HttpOperation;
import org.ocpsoft.rewrite.servlet.http.event.HttpServletRewrite;
/**
* An {@link Operation} that wraps another operation to be performed during the JavaServer Faces lifecycle.
*
* @author <a href="mailto:fabmars@gmail.com">Fabien Marsaud</a>
* @author <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
*/
public abstract class PhaseOperation<T extends PhaseOperation<T>> extends HttpOperation implements Weighted
{
private static final String REQUEST_KEY = PhaseOperation.class.getName() + "_DEFERRED";
private final Set<PhaseId> beforePhases = new HashSet<PhaseId>();
private final Set<PhaseId> afterPhases = new HashSet<PhaseId>();
/**
* Perform the wrapped operation before or after the specified phases.
*/
public abstract void performOperation(final HttpServletRewrite event, final EvaluationContext context);
/**
* Create an {@link Operation} that will defer a given {@link Operation} until one or more specified JavaServer Faces
* {@link PhaseId} instances specified via {@link #before(PhaseId...)} or {@link #after(PhaseId...)}.
*/
public static PhaseOperation<?> enqueue(final Operation operation)
{
return enqueue(operation, 0);
}
/**
* Create an {@link Operation} that will enqueue a given {@link Operation} to be performed before or after one or
* more JavaServer Faces {@link PhaseId} instances specified via {@link #before(PhaseId...)} or
* {@link #after(PhaseId...)}.
*/
@SuppressWarnings("rawtypes")
public static PhaseOperation<?> enqueue(final Operation operation, final int priority)
{
return new PhaseOperation() {
@Override
public int priority()
{
return priority;
}
@Override
public void performOperation(HttpServletRewrite event, EvaluationContext context)
{
operation.perform(event, context);
}
@Override
public String toString()
{
return "PhaseOperation.enqueue(" + operation + ", " + priority + ")";
}
};
}
/**
* Get the phases before which this {@link PhaseOperation} will be performed.
*/
public Set<PhaseId> getBeforePhases()
{
return beforePhases;
}
/**
* Get the phases after which this {@link PhaseOperation} will be performed.
*/
public Set<PhaseId> getAfterPhases()
{
return afterPhases;
}
/**
* Perform this {@link PhaseOperation} before the given phases (Except {@link PhaseId#RESTORE_VIEW}). The deferred
* {@link Operation} will be performed once for each {@link PhaseId} provided.
*/
@SuppressWarnings("unchecked")
public T before(final PhaseId... phases)
{
if (phases != null)
this.beforePhases.addAll(Arrays.asList(phases));
return (T) this;
}
/**
* Perform this {@link PhaseOperation} after the given phases (Except {@link PhaseId#RENDER_RESPONSE}). The deferred
* {@link Operation} will be performed once for each {@link PhaseId} provided.
*/
@SuppressWarnings("unchecked")
public T after(final PhaseId... phases)
{
if (phases != null)
this.afterPhases.addAll(Arrays.asList(phases));
return (T) this;
}
@Override
public final void performHttp(HttpServletRewrite event, EvaluationContext context)
{
getSortedPhaseOperations(event.getRequest()).add(new DeferredOperation(event, context, this));
}
@SuppressWarnings("unchecked")
public static ArrayList<DeferredOperation> getSortedPhaseOperations(HttpServletRequest request)
{
ArrayList<DeferredOperation> operations = (ArrayList<DeferredOperation>) request.getAttribute(REQUEST_KEY);
if (operations == null)
{
operations = new ArrayList<DeferredOperation>();
request.setAttribute(REQUEST_KEY, operations);
}
Collections.sort(operations, new WeightedComparator());
return operations;
}
public static class DeferredOperation implements Weighted
{
private final HttpServletRewrite event;
private final EvaluationContext context;
private final PhaseOperation<?> operation;
public DeferredOperation(HttpServletRewrite event, EvaluationContext context, PhaseOperation<?> operation)
{
this.event = event;
this.context = context;
this.operation = operation;
}
@Override
public int priority()
{
return operation.priority();
}
public HttpServletRewrite getEvent()
{
return event;
}
public EvaluationContext getContext()
{
return context;
}
public PhaseOperation<?> getOperation()
{
return operation;
}
}
}