tapestry/tapestry-framework/src/java/org/apache/tapestry/wml/Option.java

// Copyright 2004, 2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package org.apache.tapestry.wml;

import org.apache.hivemind.HiveMind;
import org.apache.tapestry.AbstractComponent;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;

/**
 * This component serves as a container for one item that is listed as a choice
 * in a {@link Select}. A {@link Select}offers a selection of choices from
 * which usersu may choose one or more items. The select list is created using a
 * select element which contains a collection of option elements. A string or
 * text describing the item appears between the opening and closing option tags.
 * In order to have a dynamic onpick attribute it is better to use a concrete
 * class of {@link org.apache.tapestry.link.ILinkRenderer}with the
 * {@link OptionRenderer}.
 * 
 * @author David Solis
 * @since 3.0
 */

public abstract class Option extends AbstractComponent
{

    /**
     * @see org.apache.tapestry.AbstractComponent#renderComponent(IMarkupWriter,
     *      IRequestCycle)
     */

    protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
    {
        boolean render = !cycle.isRewinding();

        if (render)
        {
            writer.begin("option");

            String value = getValue();
            if (HiveMind.isNonBlank(value)) writer.attribute("value", value);

            renderInformalParameters(writer, cycle);

            renderBody(writer, cycle);

            writer.end();
        }
    }

    public abstract String getValue();
}