/*

  * Copyright 1999-2001,2004 The Apache Software Foundation.

  * 

  * 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.apache.commons.workflow.core;

 import java.util.EmptyStackException;

 import org.apache.commons.workflow.BlockState;

 import org.apache.commons.workflow.Context;

 import org.apache.commons.workflow.Iterator;

 import org.apache.commons.workflow.Step;

 import org.apache.commons.workflow.StepException;

 import org.apache.commons.workflow.base.BaseStep;

 /**

  * <p>Locate the closest surrounding Iterator, set the nesting control

  * to <code>false</code>, and transfer control to the Iterator.</p>

  *

  * @version $Revision: 155475 $ $Date: 2005-02-26 13:31:11 +0000 (Sat, 26 Feb 2005) $

  * @author Craig R. McClanahan

  */

 public class BreakStep extends BaseStep {

     // ----------------------------------------------------------= Constructors

     /**

      * Construct a default instance of this Step.

      */

     public BreakStep() {

         super();

     }

     /**

      * Construct an instance of this Step with the specified identifier.

      *

      * @param id Step identifier

      */

     public BreakStep(String id) {

         super();

         setId(id);

     }

     // --------------------------------------------------------- Public Methods

     /**

      * Perform the executable actions related to this Step, in the context of

      * the specified Context.

      *

      * @param context The Context that is tracking our execution state

      *

      * @exception StepException if a processing error has occurred

      */

     public void execute(Context context) throws StepException {

         // Locate the closest surrounding Iterator's BlockState

         BlockState state = null;

         while (true) {

             try {

                 state = context.peekBlockState();

                 if (state.getBlock() instanceof Iterator)

                     break;

                 context.popBlockState();

                 continue;

             } catch (EmptyStackException e) {

                 throw new StepException("Must be nested in an Iterator block",

                                         this);

             }

         }

         // Set the nesting repeat indicator, and transfer control

         state.setNest(false);

         context.setNextStep(state.getBlock());

     }

     /**

      * Render a string representation of this Step.

      */

     public String toString() {

         StringBuffer sb = new StringBuffer("<core:break");

         if (getId() != null) {

             sb.append(" id=\"");

             sb.append(getId());

             sb.append("\"");

         }

         sb.append("/>");

         return (sb.toString());

     }

 }