001    // Copyright 2004, 2005 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.tapestry.services;
016    
017    import org.apache.tapestry.engine.IEngineService;
018    
019    /**
020     * Service interface for <code>tapestry.services.ServiceMap</code>, provides access to engine
021     * services defined in the HiveMind module deployment descriptors.
022     * <p>
023     * Note: In Tapestry 3.0 and earlier, a &lt;service&gt; element in the application and library
024     * specifications was used to define services. This is no longer supported.
025     * 
026     * @author Howard Lewis Ship
027     * @since 4.0
028     */
029    public interface ServiceMap
030    {
031        /**
032         * Returns the named service.
033         * 
034         * @param name
035         *            the unique name for the service, as defined by each service instance's
036         *            {@link IEngineService#getName()} method.
037         * @returns the named service
038         * @throws org.apache.hivemind.ApplicationRuntimeException
039         *             if the named service does not exist
040         */
041        IEngineService getService(String name);
042    
043        /**
044         * Returns true if the name is a known service, or false otherwise.
045         */
046    
047        boolean isValid(String name);
048    }