001// Copyright 2007, 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.internal.services;
016
017import org.apache.tapestry5.ioc.ObjectLocator;
018import org.apache.tapestry5.ioc.annotations.Inject;
019import org.apache.tapestry5.model.MutableComponentModel;
020import org.apache.tapestry5.plastic.PlasticField;
021import org.apache.tapestry5.services.transform.InjectionProvider2;
022
023/**
024 * A very late worker related to the {@link Inject} annotation that, when all other forms of injection have failed,
025 * matches the field type to a service interface.
026 */
027public class ServiceInjectionProvider implements InjectionProvider2
028{
029    private final ObjectLocator locator;
030
031    private final ComponentClassCache classCache;
032
033    public ServiceInjectionProvider(ObjectLocator locator, ComponentClassCache classCache)
034    {
035        this.locator = locator;
036        this.classCache = classCache;
037    }
038
039    public boolean provideInjection(PlasticField field, ObjectLocator locator, MutableComponentModel componentModel)
040    {
041        Class fieldType = classCache.forName(field.getTypeName());
042
043        Object inject = this.locator.getService(fieldType);
044
045        assert inject != null;
046
047        field.inject(inject);
048
049        // If we make it this far without an exception, then we were successful
050        // and should claim the field.
051
052        return true;
053    }
054
055}