proposals/henning/jsp-tags/src/java/org/apache/turbine/services/jsp/tags/BodyTag.java

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

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 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
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 *    the documentation and/or other materials provided with the
 *    distribution.
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 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
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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 body tag.
 * Tags that surround the screen content that will replace the 
 * &lt;x:screen section="body" /&gt; tag in a layout template.
 * An optional attributes parameter can be used to set the value
 * of the &lt;x:bodyAttributes /&gt;, which can also be in the
 * layout.
 * Example usage:
 * &lt;x:body attributes='onLoad="jsfunc()"'&gt;
 * some html content
 * &lt;/x:body&gt;
 *
 * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
 */
public class BodyTag extends TagSupport 
{
    static final String ATTRIBUTES = "_body_tag_attributes_";
    
    /**
     * attributes parameter can be used to add screen specific attribute values
     * to the &lt;body&gt; tag.
     */
    private String attributes;

    /** 
     * The setter for body tag attributes relevant to the screen containing
     * this tag. 
     */
    public void setAttributes(String attributes) 
    {
        pageContext.setAttribute(ATTRIBUTES, attributes, 
            PageContext.REQUEST_SCOPE);
        this.attributes = attributes;
    }
    
    /**
     * Method called when the tag is encountered.  If the layout is in
     * the body section, the contents between the body 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.BODY.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;
    }
}