| /* |
| * Copyright 2002,2004 The Apache Software Foundation. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.commons.jelly.tags.core; |
| |
| import org.apache.commons.jelly.JellyTagException; |
| import org.apache.commons.jelly.MissingAttributeException; |
| import org.apache.commons.jelly.TagSupport; |
| import org.apache.commons.jelly.XMLOutput; |
| import org.apache.commons.jelly.expression.Expression; |
| import org.apache.commons.jelly.impl.BreakException; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| /** |
| * A tag which performs an iteration while the result of an expression is true. |
| * |
| * @author <a href="mailto:eric@ericalexander.net">Eric Alexander</a> |
| * @author dIon Gillard |
| * @version $Revision: 1.15 $ |
| */ |
| public class WhileTag extends TagSupport { |
| |
| /** The Log to which logging calls will be made. */ |
| private static final Log log = LogFactory.getLog(WhileTag.class); |
| |
| /** The expression to use to determine if the while should continue */ |
| private Expression test; |
| |
| /** |
| * Create a new while tag |
| */ |
| public WhileTag() { |
| } |
| |
| /** |
| * Tag interface |
| * @param output destination for xml output |
| * @throws MissingAttributeException when the test attribute is missing |
| * @throws Exception for anything else |
| */ |
| public void doTag(XMLOutput output) throws MissingAttributeException, JellyTagException { |
| if (test != null) { |
| try { |
| while (test.evaluateAsBoolean(getContext())) { |
| if (log.isDebugEnabled()) { |
| log.debug("evaluated to true! gonna keep on chuggin!"); |
| } |
| invokeBody(output); |
| } |
| } |
| catch (BreakException e) { |
| if (log.isDebugEnabled()) { |
| log.debug("loop terminated by break: " + e, e); |
| } |
| } |
| } |
| else { |
| throw new MissingAttributeException("test"); |
| } |
| } |
| |
| // Properties |
| //------------------------------------------------------------------------- |
| |
| /** |
| * Setter for the expression |
| * @param e the expression to test |
| */ |
| public void setTest(Expression e) { |
| this.test = e; |
| } |
| } |
| |