    001// Copyright 2012-2013 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.util;
    016
    017import org.apache.tapestry5.ioc.services.SymbolProvider;
    018
    019/**
    020 * Combines multiple symbol providers.
    021 *
    022 * @since 5.4
    023 */
    024public class DelegatingSymbolProvider implements SymbolProvider
    025{
    026    private final SymbolProvider[] providers;
    027
    028    public DelegatingSymbolProvider(SymbolProvider... providers)
    029    {
    030        this.providers = providers;
    031    }
    032
    033    public String valueForSymbol(String symbolName)
    034    {
    035        for (SymbolProvider p : providers)
    036        {
    037            String value = p.valueForSymbol(symbolName);
    038
    039            if (value != null)
    040            {
    041                return value;
    042            }
    043        }
    044
    045        return null;
    046    }
    047}