package com.acme.tag;

import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.BodyTagSupport;
import javax.servlet.jsp.tagext.IterationTag;
import javax.servlet.jsp.tagext.Tag;
import javax.servlet.jsp.tagext.TagSupport;
import java.util.Collection;
import java.util.Iterator;

/**
 * A simple Tag that Iterates a given Collection
 *
 * @author Magnus Rydin
 */
public class IteratorTag extends TagSupport
{
  private Iterator iterator;
  private String type;

  public IteratorTag()
  {
    super();
  }

  /**
   * Method used by the JSP container to set the Collection to use.
   */
  public void setCollection(Collection collection)
  {
    if (collection.size() > 0) //check that the Collection have elements
      iterator = collection.iterator();
  }

  /**
   * Method used by the JSP container to set the type of the object
   * that the Tag will add to the PageContext
   */
  public void setType(String type)
  {
    this.type = type;
  }

  public int doStartTag() throws JspException
  {
    if (iterator != null)
    {
      if (hasNext())
          return EVAL_BODY_INCLUDE;
    }
    return SKIP_BODY;
  }

  public int doAfterBody() throws JspException
  {
    if (hasNext())
      return EVAL_BODY_AGAIN;
    else
      return SKIP_BODY;
  }

  private boolean hasNext()
  {
    if (iterator.hasNext())
    {
      this.pageContext.setAttribute(id, iterator.next(), PageContext.PAGE_SCOPE);
      return true;
    }
    return false;
  }
}