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.wml;
016
017import org.apache.hivemind.HiveMind;
018import org.apache.tapestry.AbstractComponent;
019import org.apache.tapestry.IMarkupWriter;
020import 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
030public 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}