    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
    015    package org.apache.tapestry5.internal.services;
    016
    017    import org.apache.tapestry5.ioc.ObjectLocator;
    018    import org.apache.tapestry5.ioc.annotations.Inject;
    019    import org.apache.tapestry5.model.MutableComponentModel;
    020    import org.apache.tapestry5.plastic.PlasticField;
    021    import 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     */
    027    public 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    }