/**
 * Copyright (c) 2010 Yahoo! Inc. All rights reserved.
 * 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. See accompanying LICENSE file.
 */
package org.apache.oozie.workflow.lite;

import org.apache.oozie.workflow.WorkflowException;
import org.apache.oozie.ErrorCode;


//TODO javadoc
public abstract class DecisionNodeHandler extends NodeHandler {

    @Override
    public final boolean enter(Context context) throws WorkflowException {
        start(context);
        return false;
    }

    @Override
    public final String exit(Context context) throws WorkflowException {
        end(context);
        String signalValue = context.getSignalValue();
        if (context.getNodeDef().getTransitions().contains(signalValue)) {
            return signalValue;
        }
        else {
            throw new WorkflowException(ErrorCode.E0721, context.getNodeDef().getName(), signalValue);
        }
    }

    public abstract void start(Context context) throws WorkflowException;

    public abstract void end(Context context) throws WorkflowException;

}