001 /** 002 * Copyright (c) 2000-2013 Liferay, Inc. All rights reserved. 003 * 004 * This library is free software; you can redistribute it and/or modify it under 005 * the terms of the GNU Lesser General Public License as published by the Free 006 * Software Foundation; either version 2.1 of the License, or (at your option) 007 * any later version. 008 * 009 * This library is distributed in the hope that it will be useful, but WITHOUT 010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 011 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more 012 * details. 013 */ 014 015 package com.liferay.taglib.core; 016 017 import com.liferay.portal.kernel.servlet.taglib.TagSupport; 018 019 /** 020 * @author Shuyang Zhou 021 */ 022 public class ChooseTag extends TagSupport { 023 024 public boolean canRun() { 025 return !_ran; 026 } 027 028 @Override 029 public int doStartTag() { 030 _ran = false; 031 032 return EVAL_BODY_INCLUDE; 033 } 034 035 public void markRan() { 036 if (_ran) { 037 throw new IllegalStateException("Another subtag has already run"); 038 } 039 040 _ran = true; 041 } 042 043 @Override 044 public void release() { 045 super.release(); 046 047 _ran = false; 048 } 049 050 private boolean _ran; 051 052 }