Source code: com/aendvari/tethys/tag/logic/IterateTag.java

   /*
    * IterateTag.java
    *
    * Copyright (c) 2001, 2002 Aendvari, Ltd. All Rights Reserved.
    *
    * See the file LICENSE for terms of use.
    *
    */
   
  package com.aendvari.tethys.tag.logic;
  
  import java.util.*;
  import java.io.IOException;
  
  import javax.servlet.http.*;
  import javax.servlet.jsp.*;
  import javax.servlet.jsp.tagext.*;
  
  import com.aendvari.common.model.*;
  
  import com.aendvari.tethys.context.*;
  import com.aendvari.tethys.context.model.*;
  
  import com.aendvari.tethys.tag.*;
  import com.aendvari.tethys.tag.model.*;
  
  
  /**
   * <p>Implementation class for the "iterate" tag.</p>
   *
   * @author  Scott Milne
   *
   */
  
  public class IterateTag extends ModelTreeBodyTag
  {
    /* Variables */
  
    /** the default name to retrieve the index by */
    static final public String DefaultIndexName = "iteratorIndex";
  
    /** the iterator to use for the items */
    private Iterator iterator;
  
    /** the name to retrieve the index by */
    private String indexName;
  
    /** the iteration index */
    private int iteratorIndex;
  
    /** the iteration context */
    private ModelContext iteratorContext;
  
    /* Constructor */
  
    public IterateTag()
    {
      super();
  
      iterator = null;
      iteratorIndex = 1;
      indexName = null;
    }
  
    public Integer getIteratorIndex()
    {
      return new Integer(iteratorIndex);
    }
  
    public String getIndexName()
    {
      return indexName;
    }
  
    public void setIndexName(String setIndexName)
    {
      indexName = setIndexName;
    }
  
    /**
     * Returns the iterator context as this tag's context, to provide
     * context changes to sub-tags.
     */
  
    public ModelContext getModelContext() { return iteratorContext; }
  
    public int doStartTag() throws JspTagException
    {
      if( iterator == null )
      {
        // establish tag context
        establishModelContext();
  
        // get the context model node
        ModelNode contextNode = modelContext.getModelNode();
  
        // get the model tree
        ModelTree modelTree = contextNode.getOwnerModelTree();
  
       // get the value from the path
       iterator = modelTree.getNodes(contextNode, path).iterator();
     }
 
     // use the default name if one was not provided
     if( indexName == null )
     {
       indexName = DefaultIndexName;
     }
 
     // since both XML and the OSM start their indexes at 1,
     // make the variable do the same
     iteratorIndex = 1;
 
     // if there is another element available, set it
     if( iterator.hasNext() )
     {
       try
       {
         setNextNode();
       }
       catch (Exception e)
       {
         throw new JspTagException("IterateTag: " + e.getMessage());
       }
 
       //
       // COMPATIBILITY NOTICE
       //
       // If you are using JSP 1.1, this value is non-functional, use the following instead:
       //
       // EVAL_BODY_TAG
       //
       return EVAL_BODY_AGAIN;
     }
     else
     {
       return SKIP_BODY;
     }
   }
 
   public int doAfterBody() throws JspException
   {
     BodyContent body = getBodyContent();
     try
     {
       body.writeOut(getPreviousOut());
     }
     catch (IOException e)
     {
       throw new JspTagException("IterateTag: " + e.getMessage());
     }
 
     // clear up so the next time the body content is empty
     body.clearBody();
 
     if( iterator.hasNext() )
     {
       try
       {
         setNextNode();
       }
       catch (Exception e)
       {
         throw new JspTagException("IterateTag: " + e.getMessage());
       }
 
       //
       // COMPATIBILITY NOTICE
       //
       // If you are using JSP 1.1, this value is non-functional, use the following instead:
       //
       // EVAL_BODY_TAG
       //
       return EVAL_BODY_AGAIN;
     }
     else
     {
       return SKIP_BODY;
     }
   }
 
   private void setNextNode() throws JspException
   {
     try
     {
       // get the context map
       ContextMap contextMap = ModelTagData.getData(
         pageContext, getDataScope()).getModelContextMap();
 
       // get the tag context
       ModelContext tagContext = getParentModelContext();
 
       ModelNode modelNode = (ModelNode)iterator.next();
 
       String indexedPath = path + "[" + iteratorIndex + "]";
 
       // now set this context into the request
       iteratorContext = new ModelContext(
         tagContext.extendLocation(name),
         modelContext.extendModelPath(indexedPath),
         modelNode);
 
       contextMap.setContext(iteratorContext);
 
       pageContext.setAttribute(indexName, getIteratorIndex());
       iteratorIndex++;
     }
     catch (Exception e)
     {
       throw new JspTagException("IterateTag:" + e.toString());
     }
   }
 
     /**
      * Clean up after processing this enumeration.
      *
      * @exception JspException if a JSP exception has occurred
      *
      */
 
     public int doEndTag() throws JspException
     {
     // Continue processing this page
     return EVAL_PAGE;
     }
 
     /**
      * Release all allocated resources.
    *
      */
 
     public void release()
     {
         super.release();
 
         iterator = null;
         iteratorIndex = 0;
     indexName = null;
     }
 }