| // Copyright 2006, 2007, 2011 The Apache Software Foundation |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package org.apache.tapestry5.ioc.services; |
| |
| import org.slf4j.Logger; |
| |
| import java.util.List; |
| |
| /** |
| * Creates a pipeline from a service interface and an ordered list of filters. Each filter is defined in terms of a |
| * filter interface: the filter interface is a variant of the service interface, where each method has an additional |
| * parameter that is an instance of the service interface. Typically, this service parameter (often named "delegate") is |
| * either the first or the last parameter of each method. |
| * <p/> |
| * The implementation of a filter method is expected to pass all of its parameters to the service instance passed into |
| * it. |
| * <p/> |
| * The interesting thing is that there may be multiple filters in the pipeline. A fabricated "bridge" object (that |
| * implements the service interface) is created to let each filter invoke methods on the next filter down the pipeline. |
| * This simplifies the model for creating pipelines, as each filter is coded as if it was directly "in front of" the |
| * terminator. In fact, it may be indirectly invoking methods on the next filter in the pipeline via a bridge instance. |
| * <p/> |
| * The builder is fairly smart about matching up service interface methods to filter interface methods, but keeping it |
| * simple is also a good idea. By convention, the final parameter of each filter method is the delegate object (the bridge or terminator). |
| */ |
| public interface PipelineBuilder |
| { |
| /** |
| * Creates a pipeline from the filters and a terminator. |
| * |
| * @param <S> service type |
| * @param <F> filter type |
| * @param logger logs any warnings generated when constructing the pipeline |
| * @param serviceInterface defines the interface for the pipeline |
| * @param filterInterface the filter interface, contributed into the pipeline |
| * @param filters sorted list of filters |
| * @param terminator end of the pipeline |
| * @return an object that encapsulates the filters and the terminator |
| */ |
| <S, F> S build(Logger logger, Class<S> serviceInterface, Class<F> filterInterface, List<F> filters, S terminator); |
| |
| /** |
| * Creates a pipeline from just the filters. A {@link DefaultImplementationBuilder default implementation} is |
| * created as the terminator. |
| * |
| * @param <S> service type |
| * @param <F> filter type |
| * @param logger logs any warnings generated when constructing the pipeline |
| * @param serviceInterface defines the interface for the pipeline |
| * @param filterInterface the filter interface, contributed into the pipeline |
| * @param filters sorted list of filters |
| * @return an object that encapsulates the filters and the default implementation |
| */ |
| <S, F> S build(Logger logger, Class<S> serviceInterface, Class<F> filterInterface, List<F> filters); |
| |
| } |