001 /* $Id: AbstractRulesImpl.java 729095 2008-12-23 20:32:22Z rahul $
002 *
003 * Licensed to the Apache Software Foundation (ASF) under one or more
004 * contributor license agreements. See the NOTICE file distributed with
005 * this work for additional information regarding copyright ownership.
006 * The ASF licenses this file to You under the Apache License, Version 2.0
007 * (the "License"); you may not use this file except in compliance with
008 * 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, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019
020 package org.apache.commons.digester;
021
022
023 import java.util.List;
024
025
026 /**
027 * <p><code>AbstractRuleImpl</code> provides basic services for <code>Rules</code> implementations.
028 * Extending this class should make it easier to create a <code>Rules</code> implementation.</p>
029 *
030 * <p><code>AbstractRuleImpl</code> manages the <code>Digester</code>
031 * and <code>namespaceUri</code> properties.
032 * If the subclass overrides {@link #registerRule} (rather than {@link #add}),
033 * then the <code>Digester</code> and <code>namespaceURI</code> of the <code>Rule</code>
034 * will be set correctly before it is passed to <code>registerRule</code>.
035 * The subclass can then perform whatever it needs to do to register the rule.</p>
036 *
037 * @since 1.5
038 */
039
040 abstract public class AbstractRulesImpl implements Rules {
041
042 // ------------------------------------------------------------- Fields
043
044 /** Digester using this <code>Rules</code> implementation */
045 private Digester digester;
046 /** Namespace uri to assoicate with subsequent <code>Rule</code>'s */
047 private String namespaceURI;
048
049 // ------------------------------------------------------------- Properties
050
051 /**
052 * Return the Digester instance with which this Rules instance is
053 * associated.
054 */
055 public Digester getDigester() {
056 return digester;
057 }
058
059 /**
060 * Set the Digester instance with which this Rules instance is associated.
061 *
062 * @param digester The newly associated Digester instance
063 */
064 public void setDigester(Digester digester) {
065 this.digester = digester;
066 }
067
068 /**
069 * Return the namespace URI that will be applied to all subsequently
070 * added <code>Rule</code> objects.
071 */
072 public String getNamespaceURI() {
073 return namespaceURI;
074 }
075
076 /**
077 * Set the namespace URI that will be applied to all subsequently
078 * added <code>Rule</code> objects.
079 *
080 * @param namespaceURI Namespace URI that must match on all
081 * subsequently added rules, or <code>null</code> for matching
082 * regardless of the current namespace URI
083 */
084 public void setNamespaceURI(String namespaceURI) {
085 this.namespaceURI = namespaceURI;
086 }
087
088 // --------------------------------------------------------- Public Methods
089
090 /**
091 * Registers a new Rule instance matching the specified pattern.
092 * This implementation sets the <code>Digester</code> and the
093 * <code>namespaceURI</code> on the <code>Rule</code> before calling {@link #registerRule}.
094 *
095 * @param pattern Nesting pattern to be matched for this Rule
096 * @param rule Rule instance to be registered
097 */
098 public void add(String pattern, Rule rule) {
099 // set up rule
100 if (this.digester != null) {
101 rule.setDigester(this.digester);
102 }
103
104 if (this.namespaceURI != null) {
105 rule.setNamespaceURI(this.namespaceURI);
106 }
107
108 registerRule(pattern, rule);
109
110 }
111
112 /**
113 * Register rule at given pattern.
114 * The the Digester and namespaceURI properties of the given <code>Rule</code>
115 * can be assumed to have been set properly before this method is called.
116 *
117 * @param pattern Nesting pattern to be matched for this Rule
118 * @param rule Rule instance to be registered
119 */
120 abstract protected void registerRule(String pattern, Rule rule);
121
122 /**
123 * Clear all existing Rule instance registrations.
124 */
125 abstract public void clear();
126
127
128 /**
129 * Return a List of all registered Rule instances that match the specified
130 * nesting pattern, or a zero-length List if there are no matches. If more
131 * than one Rule instance matches, they <strong>must</strong> be returned
132 * in the order originally registered through the <code>add()</code>
133 * method.
134 *
135 * @param pattern Nesting pattern to be matched
136 *
137 * @deprecated Call match(namespaceURI,pattern) instead.
138 */
139 public List<Rule> match(String pattern) {
140 return match(namespaceURI, pattern);
141 }
142
143
144 /**
145 * Return a List of all registered Rule instances that match the specified
146 * nesting pattern, or a zero-length List if there are no matches. If more
147 * than one Rule instance matches, they <strong>must</strong> be returned
148 * in the order originally registered through the <code>add()</code>
149 * method.
150 *
151 * @param namespaceURI Namespace URI for which to select matching rules,
152 * or <code>null</code> to match regardless of namespace URI
153 * @param pattern Nesting pattern to be matched
154 */
155 abstract public List<Rule> match(String namespaceURI, String pattern);
156
157
158 /**
159 * Return a List of all registered Rule instances, or a zero-length List
160 * if there are no registered Rule instances. If more than one Rule
161 * instance has been registered, they <strong>must</strong> be returned
162 * in the order originally registered through the <code>add()</code>
163 * method.
164 */
165 abstract public List<Rule> rules();
166
167 }