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.binding;
016
017import org.apache.hivemind.ApplicationRuntimeException;
018import org.apache.hivemind.Location;
019import org.apache.hivemind.util.Defense;
020import org.apache.tapestry.IComponent;
021import org.apache.tapestry.coerce.ValueConverter;
022
023/**
024 * A binding where the path is the id of a child component.
025 * 
026 * @author Howard M. Lewis Ship
027 * @since 4.0
028 */
029public class ComponentBinding extends AbstractBinding
030{
031    private final IComponent _component;
032
033    private final String _componentId;
034
035    public ComponentBinding(String description, ValueConverter valueConverter, Location location,
036            IComponent component, String componentId)
037    {
038        super(description, valueConverter, location);
039
040        Defense.notNull(component, "component");
041        Defense.notNull(componentId, "componentId");
042
043        _component = component;
044        _componentId = componentId;
045    }
046
047    public Object getObject()
048    {
049        try
050        {
051            return _component.getComponent(_componentId);
052        }
053        catch (Exception ex)
054        {
055            throw new ApplicationRuntimeException(ex.getMessage(), getLocation(), ex);
056        }
057    }
058
059    public Object getComponent()
060    {
061        return _component;
062    }
063
064}