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
015package org.apache.tapestry.spec;
016
017import java.util.Map;
018
019import org.apache.hivemind.LocationHolder;
020import 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 */
028public 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}