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.tapestry.IMarkupWriter;
018import org.apache.tapestry.IRequestCycle;
019import org.apache.tapestry.form.IPropertySelectionModel;
020
021/**
022 * SelectionField specifies a postfield element and it is used to complement the
023 * {@link PropertySelection}component.
024 * 
025 * @author David Solis
026 * @since 3.0
027 */
028public abstract class SelectionField extends AbstractPostfield
029{
030    /**
031     * @see org.apache.tapestry.form.AbstractFormComponent#rewindFormComponent(org.apache.tapestry.IMarkupWriter, org.apache.tapestry.IRequestCycle)
032     */
033    protected void rewindFormComponent(IMarkupWriter writer, IRequestCycle cycle)
034    {
035        String optionValue = cycle.getParameter(getName());
036        IPropertySelectionModel model = getModel();
037        Object value = (optionValue == null) ? null : model.translateValue(optionValue);
038
039        updateValue(value);
040    }
041
042    public abstract IPropertySelectionModel getModel();
043}