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        public abstract boolean getRenderTag();
030        
031        protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
032        {
033            Object conditionObject = cycle.getAttribute(IfBean.IF_VALUE_ATTRIBUTE);
034    
035            if (conditionObject instanceof Boolean && !((Boolean) conditionObject).booleanValue()) 
036            {
037                String element = HiveMind.isNonBlank(getElement()) ? getElement() : getTemplateTagName();
038                
039                boolean render = !cycle.isRewinding() && (getRenderTag() || HiveMind.isNonBlank(getElement()));
040                
041                if (render)
042                {
043                    writer.begin(element);
044                    renderInformalParameters(writer, cycle);
045                }
046    
047                renderBody(writer, cycle);
048                
049                if (render)
050                    writer.end(element);
051            }
052        }
053    }