flatsequenceexpression.java

一个工作流设计及定义的系统,可以直接与数据库结合进行系统工作流程的定义及应用.

/*
 * Copyright (c) 2005, John Mettraux, OpenWFE.org
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 * 
 * . Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.  
 * 
 * . Redistributions in binary form must reproduce the above copyright notice, 
 *   this list of conditions and the following disclaimer in the documentation 
 *   and/or other materials provided with the distribution.
 * 
 * . Neither the name of the "OpenWFE" nor the names of its contributors may be
 *   used to endorse or promote products derived from this software without
 *   specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * $Id: FlatSequenceExpression.java,v 1.11 2005/05/17 16:14:47 jmettraux Exp $
 */

//
// FlatSequenceExpression.java
//
// [e-mail]
//
// generated with 
// jtmpl 1.1.01 2004/05/19 ([e-mail])
//

package openwfe.org.engine.expressions;

import openwfe.org.ApplicationContext;
import openwfe.org.engine.workitem.InFlowWorkItem;
import openwfe.org.engine.expressions.raw.RawExpression;


/**
 * With this sequence expression, the children are chained together : the first
 * child, instead of replying to the sequence, directly applies the next
 * child.
 *
 * <p><font size=2>CVS Info :
 * <br>$Author: jmettraux $
 * <br>$Id: FlatSequenceExpression.java,v 1.11 2005/05/17 16:14:47 jmettraux Exp $ </font>
 *
 * @author [e-mail]
 */
public class FlatSequenceExpression

    extends AbstractCompositeFlowExpression

{

    private final static org.apache.log4j.Logger log = org.apache.log4j.Logger
        .getLogger(FlatSequenceExpression.class.getName());

    //
    // CONSTANTS & co

    //
    // FIELDS

    //
    // CONSTRUCTORS

    //
    // METHODS from FlowExpression

    /**
     * Inits the expression.
     */
    public void init 
        (final ApplicationContext context,
         final FlowExpressionId parentId, 
         final FlowExpressionId id, 
         final RawExpression generatingExpression,
         final Object raw,
         final InFlowWorkItem currentWi)
    throws 
        BuildException
    {
        super.init
            (context, 
             parentId,
             id,
             generatingExpression,
             raw,
             currentWi);

        //
        // chain the children together
        
        if (generatingExpression.getProcessDefinition() != null) return;
            // droflo and other editors do not need to have chained 
            // children ...
        
        //log.debug("init() chaining children...");
        //log.debug("init() fetching parent : "+parentId);

        final FlowExpression parentExpression = 
            getExpressionPool().fetch(parentId);

        FlowExpressionId previousExpressionId = null;
        FlowExpression currentExpression = null;

        final java.util.Iterator it = getChildren().iterator();
        while (it.hasNext())
        {
            FlowExpressionId childId = (FlowExpressionId)it.next();

            if (currentExpression != null)
            {
                currentExpression.setNext(childId);
                currentExpression.storeItself();

                log.debug
                    ("init() \n"+currentExpression.getId()+
                     "\n  --next-->\n"+currentExpression.getNext());
            }

            currentExpression = getExpressionPool().fetch(childId);

            if (currentExpression != null)
            {
                currentExpression.setPrevious(previousExpressionId);
                previousExpressionId = currentExpression.getId();

                log.debug
                    ("init() \n"+currentExpression.getId()+
                     "\n  --previous-->\n"+currentExpression.getPrevious());

                //
                // the children parent is linked to the parent of the 
                // sequence.
                // this is very important for setting variables...
                //
                currentExpression.setParent(parentId);
                currentExpression.storeItself();

                if (( ! it.hasNext()) && parentExpression != null)
                {
                    parentExpression.replaceChild(getId(), childId);
                }
            }
        }

        if (parentExpression != null)
        {
            parentExpression.getVariables().putAll(this.getVariables());

            parentExpression.storeItself();
                // once for all children

            //debugVariables("FlatSequence.init()");
        }
    }

    public void apply (final InFlowWorkItem wi) 
        throws ApplyException
    {
        //
        // apply the first child ...
        
        if (getChildren().size() < 1) return;

        //log.debug("apply() applying first child "+getChildren().get(0));

        getExpressionPool().apply((FlowExpressionId)getChildren().get(0), wi);

        //
        // remove self from pool (it's OK, the children are linked to
        // this expression's parent).
        
        getExpressionPool().removeExpression(this);
    }

    public void reply (final InFlowWorkItem wi)
        throws ReplyException
    {
        //log.debug("reply() end of sequence.");

        //
        // the last of the chained children will reply
        // so there is nothing to do here, this method will never get called.
        
        //replyToParent(wi);
    }

    //
    // METHODS

    //
    // STATIC METHODS

}