    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}