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1   /*
2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/pattern/Pattern.java,v 1.10 2005/06/26 16:18:57 elharo Exp $
3    * $Revision: 1.10 $
4    * $Date: 2005/06/26 16:18:57 $
5    *
6    * ====================================================================
7    *
8    * Copyright (C) 2000-2002 bob mcwhirter & James Strachan.
9    * All rights reserved.
10   *
11   * Redistribution and use in source and binary forms, with or without
12   * modification, are permitted provided that the following conditions
13   * are met:
14   * 
15   * 1. Redistributions of source code must retain the above copyright
16   *    notice, this list of conditions, and the following disclaimer.
17   *
18   * 2. Redistributions in binary form must reproduce the above copyright
19   *    notice, this list of conditions, and the disclaimer that follows 
20   *    these conditions in the documentation and/or other materials 
21   *    provided with the distribution.
22   *
23   * 3. The name "Jaxen" must not be used to endorse or promote products
24   *    derived from this software without prior written permission.  For
25   *    written permission, please contact license@jaxen.org.
26   * 
27   * 4. Products derived from this software may not be called "Jaxen", nor
28   *    may "Jaxen" appear in their name, without prior written permission
29   *    from the Jaxen Project Management (pm@jaxen.org).
30   * 
31   * In addition, we request (but do not require) that you include in the 
32   * end-user documentation provided with the redistribution and/or in the 
33   * software itself an acknowledgement equivalent to the following:
34   *     "This product includes software developed by the
35   *      Jaxen Project (http://www.jaxen.org/)."
36   * Alternatively, the acknowledgment may be graphical using the logos 
37   * available at http://www.jaxen.org/
38   *
39   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
40   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
41   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
42   * DISCLAIMED.  IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT
43   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
45   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
46   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
47   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
48   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
49   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50   * SUCH DAMAGE.
51   *
52   * ====================================================================
53   * This software consists of voluntary contributions made by many 
54   * individuals on behalf of the Jaxen Project and was originally 
55   * created by bob mcwhirter <bob@werken.com> and 
56   * James Strachan <jstrachan@apache.org>.  For more information on the 
57   * Jaxen Project, please see <http://www.jaxen.org/>.
58   * 
59   * $Id: Pattern.java,v 1.10 2005/06/26 16:18:57 elharo Exp $
60   */
61  
62  package org.jaxen.pattern;
63  
64  import org.jaxen.Context;
65  import org.jaxen.JaxenException;
66  
67  /*** <p><code>Pattern</code> defines the behaviour for pattern in
68    * the XSLT processing model.</p>
69    *
70    * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
71    * @version $Revision: 1.10 $
72    */
73  public abstract class Pattern {
74  
75      // These node numbers are compatible with both DOM and dom4j's node types
76      /*** Matches Element nodes */
77      public static final short ELEMENT_NODE = 1;
78      /*** Matches attribute nodes */
79      public static final short ATTRIBUTE_NODE = 2;
80      /*** Matches text nodes */
81      public static final short TEXT_NODE = 3;
82      /*** Matches CDATA section nodes */
83      public static final short CDATA_SECTION_NODE = 4;
84      /*** Matches entity reference nodes */
85      public static final short ENTITY_REFERENCE_NODE = 5;
86      /*** Matches entity nodes */
87      //public static final short ENTITY_NODE = 6;
88      /*** Matches ProcessingInstruction */
89      public static final short PROCESSING_INSTRUCTION_NODE = 7;
90      /*** Matches comment nodes */
91      public static final short COMMENT_NODE = 8;
92      /*** Matches document nodes */
93      public static final short DOCUMENT_NODE = 9;
94      /*** Matches DocumentType nodes */
95      public static final short DOCUMENT_TYPE_NODE = 10;
96      //public static final short DOCUMENT_FRAGMENT_NODE = 11;
97      //public static final short NOTATION_NODE = 12;
98      
99      /*** Matches a Namespace Node */
100     // This has the same value as the DOM Level 3 XPathNamespace type
101     public static final short NAMESPACE_NODE = 13;
102     
103     /*** Does not match any valid node */
104     public static final short UNKNOWN_NODE = 14;
105     
106     /*** The maximum number of node types for sizing purposes */
107     public static final short MAX_NODE_TYPE = 14;
108 
109     /*** Matches any node */
110     public static final short ANY_NODE = 0;
111     
112     /*** Matches no nodes */
113     public static final short NO_NODE = 14;
114     
115     
116     /*** 
117      * 
118      * @param node ????
119      * @param context ????
120      * @return true if the pattern matches the given node
121      * @throws JaxenException  if ????
122       */
123     public abstract boolean matches( Object node, Context context ) throws JaxenException;
124     
125     /*** Returns the default resolution policy of the pattern according to the
126       * <a href="http://www.w3.org/TR/xslt11/#conflict">
127       * XSLT conflict resolution rules</a>.
128       *  
129      * @return 0.5; the default priority defined in XSLT
130      * 
131      * @see <a href="http://www.w3.org/TR/xslt#conflict" target="_top">Section 5.5 of the XSLT specification</a>
132       * 
133       */
134     public double getPriority() 
135     {
136         return 0.5;
137     }
138     
139     /*** If this pattern is a union pattern then this
140       * method should return an array of patterns which
141       * describe the union pattern, which should contain more than one pattern.
142       * Otherwise this method should return null.
143       *
144       * @return an array of the patterns which make up this union pattern
145       * or null if this pattern is not a union pattern
146       */
147     public Pattern[] getUnionPatterns() 
148     {
149         return null;
150     }
151 
152     
153     /*** 
154      * Returns the type of node the pattern matches.
155      * 
156      * @return <code>ANY_NODE</code> unless overridden
157       */
158     public short getMatchType() 
159     {
160         return ANY_NODE;
161     }
162 
163 
164     /*** For patterns which only match an ATTRIBUTE_NODE or an 
165       * ELEMENT_NODE then this pattern may return the name of the
166       * element or attribute it matches. This allows a more efficient
167       * rule matching algorithm to be performed, rather than a brute 
168       * force approach of evaluating every pattern for a given Node.
169       *
170       * @return the name of the element or attribute this pattern matches
171       * or null if this pattern matches any or more than one name
172       */
173     public String getMatchesNodeName() 
174     {
175         return null;
176     }
177     
178     
179     public Pattern simplify() 
180     {
181         return this;
182     }
183     
184     /*** Returns a textual representation of this pattern
185      * 
186      * @return the usual string form of this XSLT pattern
187      */
188     public abstract String getText();
189 
190 }