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.wml;
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     * The setvar element specifies the variable to set in the current browser context as a side effect
024     * of executing a task.
025     * 
026     * @author David Solis
027     * @since 3.0
028     */
029    
030    public abstract class Setvar extends AbstractComponent
031    {
032        /**
033         * @see AbstractComponent#renderComponent(IMarkupWriter, IRequestCycle)
034         */
035    
036        protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
037        {
038            if (cycle.isRewinding())
039                return;
040    
041            writer.beginEmpty("setvar");
042    
043            writer.attribute("name", getName());
044    
045            renderInformalParameters(writer, cycle);
046    
047            String value = getValue();
048    
049            if (HiveMind.isNonBlank(value))
050                writer.attribute("value", value);
051            else
052                writer.attribute("value", "");
053    
054            writer.closeTag();
055        }
056    
057        public abstract String getName();
058    
059        public abstract String getValue();
060    }