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.spec;
016    
017    import java.util.Map;
018    
019    import org.apache.hivemind.LocationHolder;
020    import org.apache.tapestry.util.IPropertyHolder;
021    
022    /**
023     * Defines an "extension", which is much like a helper bean, but is part of a library or application
024     * specification (and has the same lifecycle as the application).
025     * 
026     * @author glongman@intelligentworks.com
027     */
028    public interface IExtensionSpecification extends IPropertyHolder, LocationHolder
029    {
030        public abstract String getClassName();
031    
032        public abstract void setClassName(String className);
033    
034        public abstract void addConfiguration(String propertyName, String value);
035    
036        /**
037         * Returns an immutable Map of the configuration; keyed on property name, with values as
038         * properties to assign.
039         */
040        public abstract Map getConfiguration();
041    
042        /**
043         * Invoked to instantiate an instance of the extension and return it. It also configures
044         * properties of the extension.
045         */
046        public abstract Object instantiateExtension();
047    
048        /**
049         * Returns true if the extensions should be instantiated immediately after the containing
050         * {@link org.apache.tapestry.spec.LibrarySpecification}if parsed. Non-immediate extensions are
051         * instantiated only as needed.
052         */
053        public abstract boolean isImmediate();
054    
055        public abstract void setImmediate(boolean immediate);
056    }