tapestry/tapestry-framework/src/java/org/apache/tapestry/binding/MessageBinding.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.binding;

import org.apache.hivemind.Location;
import org.apache.hivemind.util.Defense;
import org.apache.tapestry.IComponent;
import org.apache.tapestry.coerce.ValueConverter;

/**
 * A binding that connects directly to a localized string for a component.
 * <p>
 * Note: Renamed from StringBinding to MessageBinding in release 4.0.
 * 
 * @see IComponent#getMessages()
 * @author Howard Lewis Ship
 * @since 2.0.4
 */

public class MessageBinding extends AbstractBinding
{
    private final IComponent _component;

    protected MessageBinding(String description, ValueConverter valueConverter, Location location,
            IComponent component, String key)
    {
        super(key, valueConverter, location);

        Defense.notNull(component, "component");
        Defense.notNull(key, "key");

        _component = component;
    }

    public Object getComponent()
    {
        return _component;
    }

    public String getKey()
    {
        return _description;
    }

    /**
     * Accesses the specified localized string. Never returns null.
     */

    public Object getObject()
    {
        return _component.getMessages().getMessage(_description);
    }

    public String toString()
    {
        StringBuffer buffer = new StringBuffer("MessageBinding");
        buffer.append('[');
        buffer.append(_component.getExtendedId());
        buffer.append(' ');
        buffer.append(_description);
        buffer.append(']');

        return buffer.toString();
    }
}