org.springframework.webflow.action.CompositeAction Maven / Gradle / Ivy
/*
* Copyright 2002-2006 the original author or authors.
*
* 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.springframework.webflow.action;
import java.util.ArrayList;
import java.util.List;
import org.springframework.core.style.ToStringCreator;
import org.springframework.util.Assert;
import org.springframework.webflow.core.collection.LocalAttributeMap;
import org.springframework.webflow.core.collection.MutableAttributeMap;
import org.springframework.webflow.execution.Action;
import org.springframework.webflow.execution.Event;
import org.springframework.webflow.execution.RequestContext;
/**
* An action that will execute an ordered chain of other actions when executed.
*
* The event id of the last not-null result returned by the executed actions
* will be used as the result event id of the composite action. Lacking that,
* the action will return the "success" event.
*
* The resulting event will have an "actionResults" event attribute
* with a list of all events returned by the executed actions, including the null
* events. This allows you to relate an executed action and its result event by
* their index in the list.
*
* This is the classic GoF composite design pattern.
*
* @author Keith Donald
*/
public class CompositeAction extends AbstractAction {
/**
* The resulting event whill have an attribute of this name which holds a
* list of all events returned by the executed actions. ("actionResults")
*/
public static final String ACTION_RESULTS_ATTRIBUTE_NAME = "actionResults";
/**
* The actions to execute.
*/
private Action[] actions;
/**
* Should execution stop if one action returns an error event?
*/
private boolean stopOnError;
/**
* Create a composite action composed of given actions.
* @param actions the actions
*/
public CompositeAction(Action[] actions) {
Assert.notEmpty(actions, "At least one action is required");
this.actions = actions;
}
/**
* Returns the actions contained by this composite action.
* @return the actions
*/
protected Action[] getActions() {
return actions;
}
/**
* Returns the stop on error flag.
*/
public boolean isStopOnError() {
return stopOnError;
}
/**
* Sets the stop on error flag. This determines whether or not execution
* should stop with the first action that returns an error event. In the
* error case, the composite action will also return the "error" event.
*/
public void setStopOnError(boolean stopOnError) {
this.stopOnError = stopOnError;
}
public Event doExecute(RequestContext context) throws Exception {
Action[] actions = getActions();
String eventId = getEventFactorySupport().getSuccessEventId();
MutableAttributeMap eventAttributes = new LocalAttributeMap();
List actionResults = new ArrayList(actions.length);
for (int i = 0; i < actions.length; i++) {
Event result = actions[i].execute(context);
actionResults.add(result);
if (result != null) {
eventId = result.getId();
if (isStopOnError() && result.getId().equals(getEventFactorySupport().getErrorEventId())) {
break;
}
}
}
eventAttributes.put(ACTION_RESULTS_ATTRIBUTE_NAME, actionResults);
return new Event(this, eventId, eventAttributes);
}
public String toString() {
return new ToStringCreator(this).append("actions", getActions()).append("stopOnError", isStopOnError())
.toString();
}
}