/*
* Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
* Free SoftwareFoundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*
* $Id: BodyTag.java,v 1.2 2004/09/29 00:12:48 cvs Exp $
*/
package javax.servlet.jsp.tagext;
import javax.servlet.jsp.JspException;
/**
* BodyTag lets tags access the generated tag contents and it allows
* tag looping. For example, a SQL tag may use the enclosed SQL to
* update a table. A BodyTag must explicitly write the contents the
* enclosing stream.
*
* <pre><code>
* if (tag.doStartTag() == EVAL_BODY_TAG) {
* out = pageContext.pushBody();
* tag.setBodyContent(out);
* tag.doInitBody();
* do {
* ...
* } while (tag.doAfterBody() == EVAL_BODY_AGAIN);
* out = pageContent.popBody();
* }
* if (tag.doEndTag() == SKIP_PAGE)
* return;
* </code><pre>
*/
public interface BodyTag extends IterationTag {
/**
* Constant returned by doStartTag to evaluate a tag body.
*
* @deprecated
*/
public final static int EVAL_BODY_TAG = 2;
/**
* Constant returned by doStartTag to evaluate a tag body.
*/
public final static int EVAL_BODY_BUFFERED = 2;
/**
* Sets the BodyContent stream. A tag calls setBodyContent before calling
* doInitBody()
*
* @param out The body content for tag and its contents.
*/
public void setBodyContent(BodyContent out);
/**
* Tags call doInitBody before processing the tag body. doInitBody is
* called after setBodyContent. It is called only once for each tag, even
* if the tag loops.
*
* <p>empty tags and tags returning SKIP_BODY do not call
* doInitBody and doAfterBody.
*
* <pre><code>
* if (tag.doStartTag() == EVAL_BODY_TAG) {
* out = pageContext.pushBody();
* tag.setBodyContent(out);
* tag.doInitBody();
* ...
* }
* </code></pre>
*/
public void doInitBody() throws JspException;
/**
* Tags call doAfterBody after processing the tag body. Tags writing
* to the output stream must write the body to the enclosing JspWriter.
* Tags can loop by returning EVAL_PAGE and stop by returning SKIP_PAGE.
*
* <p>empty tags and tags returning SKIP_BODY do not call
* doInitBody and doAfterBody.
*
* <p>Here's an example of a tag that copies its contents
* to the output (assuming setBodyContent sets bodyOut):
* <pre><code>
* public int doAfterBody() throws JspException
* {
* try {
* bodyOut.writeOut(bodyOut.getEnclosingWriter());
* } catch (IOException e) {
* throw JspException(String.valueOf(e));
* }
*
* return SKIP_PAGE;
* }
* </code></pre>
*
* @return EVAL_PAGE to repeat the tag and SKIP_PAGE to stop.
*/
public int doAfterBody() throws JspException;
}