1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/FunctionContext.java,v 1.9 2005/06/28 13:44:44 elharo Exp $
3 * $Revision: 1.9 $
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: FunctionContext.java,v 1.9 2005/06/28 13:44:44 elharo Exp $
60 */
61
62
63 package org.jaxen;
64
65 /*** Implemented by classes that know how to resolve XPath function names and
66 * namespaces to implementations of these functions.
67 *
68 * <p>
69 * By using a custom <code>FunctionContext</code>, new or different
70 * functions may be installed and available to XPath expression writers.
71 * </p>
72 *
73 * @see XPathFunctionContext
74 *
75 * @author <a href="mailto:bob@werken.com">bob mcwhirter</a>
76 */
77 public interface FunctionContext
78 {
79 /*** An implementation should return a <code>Function</code> implementation object
80 * based on the namespace URI and local name of the function-call
81 * expression.
82 *
83 * <p>
84 * It must not use the prefix parameter to select an implementation,
85 * because a prefix could be bound to any namespace; the prefix parameter
86 * could be used in debugging output or other generated information.
87 * The prefix may otherwise be completely ignored.
88 * </p>
89 *
90 * @param namespaceURI the namespace URI to which the prefix parameter
91 * is bound in the XPath expression. If the function
92 * call expression had no prefix, the namespace URI
93 * is <code>null</code>.
94 * @param prefix the prefix that was used in the function call
95 * expression
96 * @param localName the local name of the function-call expression.
97 * If there is no prefix, then this is the whole
98 * name of the function.
99 *
100 * @return a Function implementation object.
101 * @throws UnresolvableException when the function cannot be resolved
102 */
103 Function getFunction( String namespaceURI,
104 String prefix,
105 String localName ) throws UnresolvableException;
106 }