package org.apache.turbine.services.jsp.tags;

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 * The Apache Software License, Version 1.1
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 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
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 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.TagSupport;

/**
 * Supporting class for the head tag.
 * Tags that surround the screen content that will replace the 
 * &lt;x:screen section="head" /&gt; tag in a layout template.
 * Example usage:
 * &lt;x:head&gt;&lt;title&gt;Login&lt;/title&gt;&lt;/x:head&gt;
 *
 * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
 */
public class HeadTag extends TagSupport 
{
    /**
     * Method called when the start tag is encountered.  If the layout is 
     * in the head section, the contents between the head tags are executed.
     * Otherwise they are skipped.
     *
     * @return EVAL_BODY_INCLUDE, if the section has been set to body
     * or SKIP_BODY, if this section is not active.
     */
	public int doStartTag() throws JspException 
    {
        boolean isActive = ScreenTag.HEAD.equals(
            pageContext.getAttribute(ScreenTag.SECTION_KEY, 
                PageContext.REQUEST_SCOPE) );
        if (isActive)
        {
		     return EVAL_BODY_INCLUDE;
        }
        return SKIP_BODY;
	}
    
    /**
     * Method called when the end tag is encountered; it does nothing.  
     *
     * @return EVAL_PAGE
     */
	public int doEndTag() throws JspException 
    {
		return EVAL_PAGE;
	}
}