1 /*
2 * $Header$
3 * $Revision$
4 * $Date$
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 * $Id$
46 */
47
48
49 package org.jaxen;
50
51 /** Resolves namespace prefixes to namespace URIs.
52 *
53 * <p>
54 * The prefixes used within an XPath expression are
55 * independent of those used within any target document.
56 * When evaluating an XPath against a document, only
57 * the resolved namespace URIs are compared, not their
58 * prefixes.
59 * </p>
60 *
61 * <p>
62 * A <code>NamespaceContext</code> is responsible for
63 * translating prefixes as they appear in XPath expressions
64 * into URIs for comparison. A document's prefixes are
65 * resolved internal to the document based upon its own
66 * namespace nodes.
67 * </p>
68 *
69 * <p>
70 * Implementations of this interface should implement <code>Serializable</code>.
71 * </p>
72 *
73 * @see BaseXPath
74 * @see Navigator#getElementNamespaceUri
75 * @see Navigator#getAttributeNamespaceUri
76 *
77 * @author <a href="mailto:bob@werken.com">bob mcwhirter</a>
78 */
79 public interface NamespaceContext
80 {
81 /** Translate the provided namespace prefix into
82 * the matching bound namespace URI.
83 *
84 * <p>
85 * In XPath, there is no such thing as a 'default namespace'.
86 * The empty prefix <strong>always</strong> resolves to the empty
87 * namespace URI. This method should return null for the
88 * empty prefix.
89 * Similarly, the prefix "xml" always resolves to
90 * the URI "http://www.w3.org/XML/1998/namespace".
91 * </p>
92 *
93 * @param prefix the namespace prefix to resolve
94 *
95 * @return the namespace URI bound to the prefix; or null if there
96 * is no such namespace
97 */
98 String translateNamespacePrefixToUri(String prefix);
99 }