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.engine;
016    
017    import org.apache.tapestry.spec.IComponentSpecification;
018    
019    /**
020     * A provider of enhanced classes, classes with new methods and new attributes,
021     * and possibly, implementing new Java interfaces. The primary use of class
022     * enhancement is to automate the creation of transient and persistant
023     * properties.
024     * <p>
025     * Implementations of this interface must be threadsafe.
026     * 
027     * @author Howard Lewis Ship
028     * @since 3.0
029     * @deprecated To be removed in 4.1
030     * @see org.apache.tapestry.services.ComponentConstructorFactory
031     */
032    
033    public interface IComponentClassEnhancer
034    {
035    
036        /**
037         * Used to access the class for a given component (or page). Returns the
038         * specified class, or an enhanced version of the class if the component
039         * requires enhancement.
040         * 
041         * @param specification
042         *            the specification for the component
043         * @param className
044         *            the name of base class to enhance, as extracted from the
045         *            specification (or possibly, from a default).
046         * @throws org.apache.tapestry.ApplicationRuntimeException
047         *             if the class does not exist, is invalid, or may not be
048         *             enhanced.
049         */
050    
051        Class getEnhancedClass(IComponentSpecification specification,
052                String className);
053    }