/*
* 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.commons.scxml2.model;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.scxml2.ActionExecutionContext;
import org.apache.commons.scxml2.Context;
import org.apache.commons.scxml2.Evaluator;
import org.apache.commons.scxml2.SCXMLExpressionException;
import org.apache.commons.scxml2.TriggerEvent;
import org.apache.commons.scxml2.semantics.ErrorConstants;
/**
* The class in this SCXML object model that corresponds to the
* <if> SCXML element, which serves as a container for conditionally
* executed elements. <else> and <elseif> can optionally
* appear within an <if> as immediate children, and serve to partition
* the elements within an <if>.
*
*/
public class If extends Action implements ActionsContainer {
/**
* Serial version UID.
*/
private static final long serialVersionUID = 1L;
/**
* An conditional expression which can be evaluated to true or false.
*/
private String cond;
/**
* The set of executable elements (those that inheriting from
* Action) that are contained in this <if> element.
*/
private List<Action> actions;
/**
* The boolean value that dictates whether the particular child action
* should be executed.
*/
private boolean execute;
/**
* Constructor.
*/
public If() {
super();
this.actions = new ArrayList<Action>();
this.execute = false;
}
@Override
public final String getContainerElementName() {
return ELEM_IF;
}
/**
* Get the executable actions contained in this <if>.
*
* @return Returns the actions.
*/
public final List<Action> getActions() {
return actions;
}
/**
* Add an Action to the list of executable actions contained in
* this <if>.
*
* @param action The action to add.
*/
public final void addAction(final Action action) {
if (action != null) {
this.actions.add(action);
}
}
/**
* Get the conditional expression.
*
* @return Returns the cond.
*/
public final String getCond() {
return cond;
}
/**
* Set the conditional expression.
*
* @param cond The cond to set.
*/
public final void setCond(final String cond) {
this.cond = cond;
}
/**
* {@inheritDoc}
*/
@Override
public void execute(ActionExecutionContext exctx) throws ModelException, SCXMLExpressionException {
EnterableState parentState = getParentEnterableState();
Context ctx = exctx.getContext(parentState);
Evaluator eval = exctx.getEvaluator();
ctx.setLocal(getNamespacesKey(), getNamespaces());
Boolean rslt;
try {
rslt = eval.evalCond(ctx, cond);
if (rslt == null) {
if (exctx.getAppLog().isDebugEnabled()) {
exctx.getAppLog().debug("Treating as false because the cond expression was evaluated as null: '"
+ cond + "'");
}
rslt = Boolean.FALSE;
}
} catch (SCXMLExpressionException e) {
rslt = Boolean.FALSE;
exctx.getInternalIOProcessor().addEvent(new TriggerEvent(TriggerEvent.ERROR_EXECUTION, TriggerEvent.ERROR_EVENT));
exctx.getErrorReporter().onError(ErrorConstants.EXPRESSION_ERROR, "Treating as false due to error: "
+ e.getMessage(), this);
}
execute = rslt;
ctx.setLocal(getNamespacesKey(), null);
// The "if" statement is a "container"
for (Action aa : actions) {
if (execute && !(aa instanceof ElseIf)) {
aa.execute(exctx);
} else if (execute && aa instanceof ElseIf) {
break;
} else if (aa instanceof Else) {
execute = true;
} else if (aa instanceof ElseIf) {
ctx.setLocal(getNamespacesKey(), getNamespaces());
execute = eval.evalCond(ctx, ((ElseIf) aa).getCond());
ctx.setLocal(getNamespacesKey(), null);
}
}
}
}