1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/SimpleNamespaceContext.java,v 1.18 2006/06/03 20:19:26 elharo Exp $
3 * $Revision: 1.18 $
4 * $Date: 2006/06/03 20:19:26 $
5 *
6 * ====================================================================
7 *
8 * Copyright 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 are
13 * met:
14 *
15 * * Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 *
18 * * Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * * Neither the name of the Jaxen Project nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
27 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
29 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
30 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
31 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 *
38 * ====================================================================
39 * This software consists of voluntary contributions made by many
40 * individuals on behalf of the Jaxen Project and was originally
41 * created by bob mcwhirter <bob@werken.com> and
42 * James Strachan <jstrachan@apache.org>. For more information on the
43 * Jaxen Project, please see <http://www.jaxen.org/>.
44 *
45 * $Id: SimpleNamespaceContext.java,v 1.18 2006/06/03 20:19:26 elharo Exp $
46 */
47
48
49 package org.jaxen;
50
51 import java.io.Serializable;
52 import java.util.HashMap;
53 import java.util.Iterator;
54 import java.util.Map;
55
56 /***
57 * Provides mappings from namespace prefix to namespace URI to the XPath
58 * engine.
59 */
60 public class SimpleNamespaceContext implements NamespaceContext, Serializable
61 {
62
63 /***
64 *
65 */
66 private static final long serialVersionUID = -808928409643497762L;
67 // XXX should this prebind the xml prefix?
68 private Map namespaces;
69
70 /***
71 * Creates a new empty namespace context.
72 */
73 public SimpleNamespaceContext()
74 {
75 this.namespaces = new HashMap();
76 }
77
78 /***
79 * Creates a new namespace context pre-populated with the specified bindings.
80 *
81 * @param namespaces the initial namespace bindings in scope. The keys in this
82 * must be strings containing the prefixes and the values are strings
83 * containing the namespace URIs.
84 *
85 * @throws NullPointerException if the argument is null
86 * @throws ClassCastException if any keys or values in the map are not strings
87 */
88 public SimpleNamespaceContext(Map namespaces)
89 {
90 Iterator entries = namespaces.entrySet().iterator();
91 while (entries.hasNext()) {
92 Map.Entry entry = (Map.Entry) entries.next();
93 if (! (entry.getKey() instanceof String)
94 || ! (entry.getValue() instanceof String)) {
95 throw new ClassCastException("Non-string namespace binding");
96 }
97 }
98 this.namespaces = new HashMap(namespaces);
99 }
100
101 /***
102 * Adds all the namespace declarations that are in scope on the given
103 * element. In the case of an XSLT stylesheet, this would be the element
104 * that has the XPath expression in one of its attributes; e.g.
105 * <code><xsl:if test="condition/xpath/expression"></code>.
106 *
107 * @param nav the navigator for use in conjunction with
108 * <code>element</code>
109 * @param element the element to copy the namespaces from
110 * @throws UnsupportedAxisException if the navigator does not support the
111 * namespace axis
112 */
113 public void addElementNamespaces( Navigator nav, Object element )
114 throws UnsupportedAxisException
115 {
116 Iterator namespaceAxis = nav.getNamespaceAxisIterator( element );
117
118 while ( namespaceAxis.hasNext() ) {
119 Object namespace = namespaceAxis.next();
120 String prefix = nav.getNamespacePrefix( namespace );
121 String uri = nav.getNamespaceStringValue( namespace );
122 if ( translateNamespacePrefixToUri(prefix) == null ) {
123 addNamespace( prefix, uri );
124 }
125 }
126 }
127
128 // ???? What if prefix or URI is null, or both?
129 /***
130 * Binds a prefix to a URI in this context.
131 *
132 * @param prefix the namespace prefix
133 * @param URI the namespace URI
134 */
135 public void addNamespace(String prefix, String URI)
136 {
137 this.namespaces.put( prefix, URI );
138 }
139
140 public String translateNamespacePrefixToUri(String prefix)
141 {
142 if ( this.namespaces.containsKey( prefix ) )
143 {
144 return (String) this.namespaces.get( prefix );
145 }
146
147 return null;
148 }
149 }