    001// Copyright 2007, 2009 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.tapestry5.internal.services;
    016
    017import org.apache.tapestry5.Binding;
    018import org.apache.tapestry5.commons.Location;
    019import org.apache.tapestry5.internal.bindings.AbstractBinding;
    020
    021/**
    022 * Wraps a {@link StringProvider} as a read-only {@link Binding}.
    023 */
    024public class AttributeExpansionBinding extends AbstractBinding
    025{
    026    private final StringProvider provider;
    027
    028    public AttributeExpansionBinding(Location location, StringProvider provider)
    029    {
    030        super(location);
    031
    032        this.provider = provider;
    033    }
    034
    035    public Object get()
    036    {
    037        return provider.provideString();
    038    }
    039
    040    /**
    041     * Returns false. Expansions reference properties that may change arbitrarily.
    042     */
    043    @Override
    044    public boolean isInvariant()
    045    {
    046        return false;
    047    }
    048}