PrologAllowed.java :  » Ajax » zk » org » zkoss » zk » ui » ext » render » Java Open Source

/* PrologAllowed.java

  Purpose:
    
  Description:
    
  History:
    Thu Jun 12 15:28:41     2008, Created by tomyeh

Copyright (C) 2008 Potix Corporation. All Rights Reserved.

{{IS_RIGHT
  This program is distributed under LGPL Version 3.0 in the hope that
  it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zk.ui.ext.render;

/**
 * Implemented by the object returned by {@link org.zkoss.zk.ui.sys.ComponentCtrl#getExtraCtrl}
 * if it is able to generate the specified prolog before its real content.
 *
 * <p>It is used by ZK to minimize the output. Currently,
 * {@link org.zkoss.zk.ui.HtmlBasedComponent} supports it.
 * If a ZUML page has a string consisting of whitespaces, it will
 * ask the following component to generate them if {@link PrologAllowed}
 * is implemented.
 *
 * <p>For example, in the following codes, the whitespace between textbox
 * and datebox won't be converted to a label component.
 * Rather, it will ask datebox to generate by calling datebox's
 * {@link #setPrologContent}.
 *
 * <pre><code>&lt;textbox/&gt; &lt;datebox/&gt;</code></pre>
 *
 * @author tomyeh
 * @since 3.5.0
 */
public interface PrologAllowed {
  /** Sets the prolog content. It is the content generated
   * before the child components, if any.
   * <p>Default: none.
   *
   * <p>Note: the prolog is one-shot only. Once the component is
   * generated, the prolog is gone.
   */
  public void setPrologContent(String prolog);
}