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
015package org.apache.tapestry.components;
016
017import org.apache.hivemind.HiveMind;
018import org.apache.tapestry.AbstractComponent;
019import org.apache.tapestry.IMarkupWriter;
020import org.apache.tapestry.IRequestCycle;
021
022/**
023 * @author mb
024 */
025public 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}