001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one
003     *  or more contributor license agreements.  See the NOTICE file
004     *  distributed with this work for additional information
005     *  regarding copyright ownership.  The ASF licenses this file
006     *  to you under the Apache License, Version 2.0 (the
007     *  "License"); you may not use this file except in compliance
008     *  with the License.  You may obtain a copy of the License at
009     *  
010     *    http://www.apache.org/licenses/LICENSE-2.0
011     *  
012     *  Unless required by applicable law or agreed to in writing,
013     *  software distributed under the License is distributed on an
014     *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     *  KIND, either express or implied.  See the License for the
016     *  specific language governing permissions and limitations
017     *  under the License. 
018     *  
019     */
020    package org.apache.directory.server.core.filtering;
021    
022    
023    import org.apache.directory.server.core.entry.ClonedServerEntry;
024    import org.apache.directory.server.core.interceptor.context.SearchingOperationContext;
025    
026    
027    /**
028     * An entry filter is used to modify search results while they are being 
029     * returned from Cursors over ServerEntry objects.  These filters are used in
030     * conjunction with a {@link FilteringCursor}.  Multiple filters can be 
031     * applied one after the other and hence they are stack-able and applied in
032     * order.
033     *
034     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
035     * @version $Rev$
036     */
037    public interface EntryFilter
038    {
039        /**
040         * Filters the contents of search entries on the way out the door to 
041         * client callers.  These filters can and do produce side-effects on the 
042         * entry results if need be.  These entries, their attributes and values
043         * should be cloned when alterations are made to avoid altering cached
044         * entries.
045         *
046         * @param result the result to accept or reject possibly modifying it
047         * @param controls search controls associated with the invocation
048         * @return true if the entry is to be returned, false if it is rejected
049         * @throws Exception if there are failures during evaluation
050         */
051        boolean accept( SearchingOperationContext operation, ClonedServerEntry result ) throws Exception;
052    }