001/*
002 * CDDL HEADER START
003 *
004 * The contents of this file are subject to the terms of the
005 * Common Development and Distribution License, Version 1.0 only
006 * (the "License").  You may not use this file except in compliance
007 * with the License.
008 *
009 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
010 * or http://forgerock.org/license/CDDLv1.0.html.
011 * See the License for the specific language governing permissions
012 * and limitations under the License.
013 *
014 * When distributing Covered Code, include this CDDL HEADER in each
015 * file and include the License file at legal-notices/CDDLv1_0.txt.
016 * If applicable, add the following below this CDDL HEADER, with the
017 * fields enclosed by brackets "[]" replaced with your own identifying
018 * information:
019 *      Portions Copyright [yyyy] [name of copyright owner]
020 *
021 * CDDL HEADER END
022 *
023 *
024 *      Copyright 2008 Sun Microsystems, Inc.
025 */
026package org.opends.server.admin;
027
028
029
030/**
031 * An interface for determining the default behavior of a property. A
032 * property exhibits default behavior when it has no values defined.
033 * There are four different types of default behavior:
034 * <ol>
035 * <li>there is no default behavior - e.g. leaving a "description"
036 * unset has no side-effects. This default behavior is represented
037 * using the {@link UndefinedDefaultBehaviorProvider} implementation
038 * <li>the property defaults to one or more real values of the
039 * property. This default behavior is represented using the
040 * {@link DefinedDefaultBehaviorProvider} implementation
041 * <li>the property defaults to some special behavior that cannot be
042 * represented using real property values. This default behavior is
043 * represented using the {@link AliasDefaultBehaviorProvider}
044 * implementation
045 * <li>the property inherits its values from property held in another
046 * managed object (e.g. the parent managed object). This default
047 * behavior is represented using the
048 * {@link AbsoluteInheritedDefaultBehaviorProvider} and
049 * {@link RelativeInheritedDefaultBehaviorProvider} implementations.
050 * </ol>
051 * An application can perform actions based on the type of the default
052 * behavior by implementing the {@link DefaultBehaviorProviderVisitor}
053 * interface.
054 *
055 * @param <T>
056 *          The type of values represented by this provider.
057 */
058public abstract class DefaultBehaviorProvider<T> {
059
060  /**
061   * Creates a new default behavior provider.
062   */
063  protected DefaultBehaviorProvider() {
064    // No implementation required.
065  }
066
067
068
069  /**
070   * Apply a visitor to this default behavior provider.
071   *
072   * @param <R>
073   *          The return type of the visitor's methods.
074   * @param <P>
075   *          The type of the additional parameters to the visitor's
076   *          methods.
077   * @param v
078   *          The default behavior visitor.
079   * @param p
080   *          Optional additional visitor parameter.
081   * @return Returns a result as specified by the visitor.
082   */
083  public abstract <R, P>
084  R accept(DefaultBehaviorProviderVisitor<T, R, P> v, P p);
085
086
087
088  /**
089   * Performs any run-time initialization required by this default
090   * behavior provider. This may include resolving managed object
091   * paths and property names.
092   * <p>
093   * The default implementation is to do nothing.
094   *
095   * @throws Exception
096   *           If this default behavior provider could not be
097   *           initialized.
098   */
099  protected void initialize() throws Exception {
100    // Default implementation is to do nothing.
101  }
102
103}