1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/NamespaceContext.java,v 1.8 2005/06/28 13:44:44 elharo Exp $
3 * $Revision: 1.8 $
4 * $Date: 2005/06/28 13:44:44 $
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: NamespaceContext.java,v 1.8 2005/06/28 13:44:44 elharo Exp $
60 */
61
62
63 package org.jaxen;
64
65 /*** Resolves namespace prefixes to namespace URIs.
66 *
67 * <p>
68 * The prefixes used within an XPath expression are
69 * independent of those used within any target document.
70 * When evaluating an XPath against a document, only
71 * the resolved namespace URIs are compared, not their
72 * prefixes.
73 * </p>
74 *
75 * <p>
76 * A <code>NamespaceContext</code> is responsible for
77 * translating prefixes as they appear in XPath expressions
78 * into URIs for comparison. A document's prefixes are
79 * resolved internal to the document based upon its own
80 * namespace nodes.
81 * </p>
82 *
83 * @see BaseXPath
84 * @see Navigator#getElementNamespaceUri
85 * @see Navigator#getAttributeNamespaceUri
86 *
87 * @author <a href="mailto:bob@werken.com">bob mcwhirter</a>
88 */
89 public interface NamespaceContext
90 {
91 /*** Translate the provided namespace prefix into
92 * the matching bound namespace URI.
93 *
94 * <p>
95 * In XPath, there is no such thing as a 'default namespace'.
96 * The empty prefix <strong>always</strong> resolves to the empty
97 * namespace URI. This method should return null for the
98 * empty prefix.
99 * Similarly, the prefix "xml" always resolves to
100 * the URI "http://www.w3.org/XML/1998/namespace".
101 * </p>
102 *
103 * @param prefix the namespace prefix to resolve
104 *
105 * @return the namespace URI bound to the prefix; or null if there
106 * is no such namespace
107 */
108 String translateNamespacePrefixToUri(String prefix);
109 }