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
010 * docs/licenses/cddl.txt
011 * or http://www.opensource.org/licenses/cddl1.php.
012 * See the License for the specific language governing permissions
013 * and limitations under the License.
014 *
015 * When distributing Covered Code, include this CDDL HEADER in each
016 * file and include the License file at
017 * docs/licenses/cddl.txt. If applicable,
018 * add the following below this CDDL HEADER, with the fields enclosed
019 * by brackets "[]" replaced with your own identifying information:
020 * Portions Copyright [yyyy] [name of copyright owner]
021 *
022 * CDDL HEADER END
023 *
024 *
025 * Copyright 2013-2014 UnboundID Corp.
026 */
027 package com.unboundid.directory.sdk.common.types;
028
029
030 /**
031 * Context used to provide named objects to Velocity templates as they are
032 * they are used to render output. Objects stored in context are available
033 * to templates as they are rendered using variable references like
034 * '$variable'.
035 *
036 * See http://velocity.apache.org/ for more information on using Velocity.
037 */
038 public interface VelocityContext
039 {
040
041
042 /**
043 * Indicates whether a call to {@code put} will update this context
044 * if a value already exists in the context by the specified key.
045 *
046 * @return boolean where true indicates overrides are permitted.
047 */
048 boolean isPermitOverrides();
049
050
051
052 /**
053 * Adds a named object to this context. If overrides are not permitted
054 * and an object already exists in this context for the given key this
055 * method will throw a runtime exception. Following a successful call
056 * to this method, the object will be available to templates using a
057 * reference like '$key'.
058 *
059 * @param key The key which which to store the object in context.
060 * Keys prefixed with a '_' are reserved for internal use.
061 * Attempting to set a named object using a key prefixed with
062 * '_' will throw a runtime exception. Likewise attempting to
063 * put a named object in this context with a previously used
064 * key in which overrides are not permitted with throw a
065 * runtime exception.
066 *
067 * @param value The context value.
068 *
069 * @return The old object or null if there was no old object.
070 */
071 Object put(String key, Object value);
072
073
074
075 /**
076 * Gets the named object associated with a given key.
077 *
078 * @param key associated with the named object.
079 *
080 * @return The associated named object within this context or {@code null}
081 * if no object exists for the given key.
082 */
083 Object get(String key);
084
085
086
087 /**
088 * Indicates whether a named object exists in this context for a given key.
089 *
090 * @param key to use for checking whether an associated object exists in
091 * this context.
092 *
093 * @return boolean where true indicates a named object exists for the given
094 * key.
095 */
096 boolean containsKey(Object key);
097
098
099
100 /**
101 * Obtains an array of all keys for this context.
102 *
103 * @return array of all keys for this context.
104 */
105 Object[] getKeys();
106
107
108
109 /**
110 * Removes the value associated with the specified key from the context.
111 *
112 * @param key The name of the value to remove.
113 *
114 * @return The value the key was mapped to, or {@code null} the key
115 * was not previously associated with any named object in this
116 * context.
117 */
118 Object remove(Object key);
119
120 }