AbstractRulesImpl


1   /* $Id: AbstractRulesImpl.java 155412 2005-02-26 12:58:36Z dirkv $
2    *
3    * Copyright 2001-2004 The Apache Software Foundation.
4    * 
5    * Licensed under the Apache License, Version 2.0 (the "License");
6    * you may not use this file except in compliance with the License.
7    * You may obtain a copy of the License at
8    * 
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   * 
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */ 
17  
18  
19  package org.apache.commons.digester;
20  
21  
22  import java.util.List  ;
23  
24  
25  /**
26   * <p><code>AbstractRuleImpl</code> provides basic services for <code>Rules</code> implementations.
27   * Extending this class should make it easier to create a <code>Rules</code> implementation.</p>
28   * 
29   * <p><code>AbstractRuleImpl</code> manages the <code>Digester</code> 
30   * and <code>namespaceUri</code> properties.
31   * If the subclass overrides {@link #registerRule} (rather than {@link #add}),
32   * then the <code>Digester</code> and <code>namespaceURI</code> of the <code>Rule</code>
33   * will be set correctly before it is passed to <code>registerRule</code>.
34   * The subclass can then perform whatever it needs to do to register the rule.</p>
35   *
36   * @since 1.5
37   */
38  
39  abstract public class AbstractRulesImpl implements Rules {
40  
41      // ------------------------------------------------------------- Fields
42      
43      /** Digester using this <code>Rules</code> implementation */
44      private Digester digester;
45      /** Namespace uri to assoicate with subsequent <code>Rule</code>'s */
46      private String   namespaceURI;
47      
48      // ------------------------------------------------------------- Properties
49  
50      /**
51       * Return the Digester instance with which this Rules instance is
52       * associated.
53       */
54      public Digester getDigester() {
55          return digester;
56      }
57  
58      /**
59       * Set the Digester instance with which this Rules instance is associated.
60       *
61       * @param digester The newly associated Digester instance
62       */
63      public void setDigester(Digester digester) {
64          this.digester = digester;
65      }
66  
67      /**
68       * Return the namespace URI that will be applied to all subsequently
69       * added <code>Rule</code> objects.
70       */
71      public String   getNamespaceURI() {
72          return namespaceURI;
73      }
74  
75      /**
76       * Set the namespace URI that will be applied to all subsequently
77       * added <code>Rule</code> objects.
78       *
79       * @param namespaceURI Namespace URI that must match on all
80       *  subsequently added rules, or <code>null</code> for matching
81       *  regardless of the current namespace URI
82       */
83      public void setNamespaceURI(String   namespaceURI) {
84          this.namespaceURI = namespaceURI;
85      }
86  
87      // --------------------------------------------------------- Public Methods
88  
89      /**
90       * Registers a new Rule instance matching the specified pattern.
91       * This implementation sets the <code>Digester</code> and the
92       * <code>namespaceURI</code> on the <code>Rule</code> before calling {@link #registerRule}.
93       *
94       * @param pattern Nesting pattern to be matched for this Rule
95       * @param rule Rule instance to be registered
96       */
97      public void add(String   pattern, Rule rule) {
98          // set up rule
99          if (this.digester != null) {
100             rule.setDigester(this.digester);
101         }
102         
103         if (this.namespaceURI != null) {
104             rule.setNamespaceURI(this.namespaceURI);
105         }
106         
107         registerRule(pattern, rule);
108         
109     }
110     
111     /** 
112      * Register rule at given pattern.
113      * The the Digester and namespaceURI properties of the given <code>Rule</code>
114      * can be assumed to have been set properly before this method is called.
115      *
116      * @param pattern Nesting pattern to be matched for this Rule
117      * @param rule Rule instance to be registered
118      */ 
119     abstract protected void registerRule(String   pattern, Rule rule);
120 
121     /**
122      * Clear all existing Rule instance registrations.
123      */
124     abstract public void clear();
125 
126 
127     /**
128      * Return a List of all registered Rule instances that match the specified
129      * nesting pattern, or a zero-length List if there are no matches.  If more
130      * than one Rule instance matches, they <strong>must</strong> be returned
131      * in the order originally registered through the <code>add()</code>
132      * method.
133      *
134      * @param pattern Nesting pattern to be matched
135      *
136      * @deprecated Call match(namespaceURI,pattern) instead.
137      */
138     public List   match(String   pattern) {
139         return match(namespaceURI, pattern);
140     }
141 
142 
143     /**
144      * Return a List of all registered Rule instances that match the specified
145      * nesting pattern, or a zero-length List if there are no matches.  If more
146      * than one Rule instance matches, they <strong>must</strong> be returned
147      * in the order originally registered through the <code>add()</code>
148      * method.
149      *
150      * @param namespaceURI Namespace URI for which to select matching rules,
151      *  or <code>null</code> to match regardless of namespace URI
152      * @param pattern Nesting pattern to be matched
153      */
154     abstract public List   match(String   namespaceURI, String   pattern);
155 
156 
157     /**
158      * Return a List of all registered Rule instances, or a zero-length List
159      * if there are no registered Rule instances.  If more than one Rule
160      * instance has been registered, they <strong>must</strong> be returned
161      * in the order originally registered through the <code>add()</code>
162      * method.
163      */
164     abstract public List   rules();
165 
166 }
167
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags