001// Copyright 2006, 2007, 2008, 2010,, 2011 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.ioc.internal;
016
017import java.util.Collection;
018
019import org.apache.tapestry5.ioc.Configuration;
020import org.apache.tapestry5.ioc.ObjectLocator;
021
022/**
023 * Wraps a {@link java.util.Collection} as a {@link org.apache.tapestry5.ioc.Configuration} and perform validation that
024 * collected value are of the correct type.
025 */
026public class ValidatingConfigurationWrapper<T> extends AbstractConfigurationImpl<T> implements Configuration<T>
027{
028    private final TypeCoercerProxy typeCoercer;
029
030    private final String serviceId;
031
032    private final Class<T> expectedType;
033
034    private final Collection<T> collection;
035
036    public ValidatingConfigurationWrapper(Class<T> expectedType, ObjectLocator locator, TypeCoercerProxy typeCoercer,
037            Collection<T> collection, String serviceId)
038    {
039        super(expectedType, locator);
040        this.typeCoercer = typeCoercer;
041
042        this.collection = collection;
043        this.serviceId = serviceId;
044        this.expectedType = expectedType;
045    }
046
047    public void add(T object)
048    {
049        if (object == null)
050            throw new NullPointerException(IOCMessages.contributionWasNull(serviceId));
051
052        T coerced = typeCoercer.coerce(object, expectedType);
053
054        collection.add(coerced);
055    }
056
057    public void addInstance(Class<? extends T> clazz)
058    {
059        add(instantiate(clazz));
060    }
061}