001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.components;
016    
017    import org.apache.hivemind.HiveMind;
018    import org.apache.tapestry.AbstractComponent;
019    import org.apache.tapestry.IMarkupWriter;
020    import org.apache.tapestry.IRequestCycle;
021    
022    /**
023     * @author mb
024     */
025    public abstract class ElseBean extends AbstractComponent 
026    {
027        public abstract String getElement();
028        
029        protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
030        {
031            Object conditionObject = cycle.getAttribute(IfBean.IF_VALUE_ATTRIBUTE);
032    
033            if (conditionObject instanceof Boolean && !((Boolean) conditionObject).booleanValue()) 
034            {
035                String element = getElement();
036                
037                boolean render = !cycle.isRewinding() && HiveMind.isNonBlank(element);
038                
039                if (render)
040                {
041                    writer.begin(element);
042                    renderInformalParameters(writer, cycle);
043                }
044    
045                renderBody(writer, cycle);
046                
047                if (render)
048                    writer.end(element);
049            }
050        }
051    }