Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||||
VariableContext |
|
| 1.0;1 |
1 | /* |
|
2 | * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/VariableContext.java,v 1.9 2005/09/25 11:40:36 elharo Exp $ |
|
3 | * $Revision: 1.9 $ |
|
4 | * $Date: 2005/09/25 11:40:36 $ |
|
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: VariableContext.java,v 1.9 2005/09/25 11:40:36 elharo Exp $ |
|
60 | */ |
|
61 | ||
62 | ||
63 | package org.jaxen; |
|
64 | ||
65 | /** Resolves variable bindings within an XPath expression. |
|
66 | * |
|
67 | * <p> |
|
68 | * Variables within an XPath expression are denoted using |
|
69 | * notation such as <code>$varName</code> or |
|
70 | * <code>$nsPrefix:varName</code>, and may |
|
71 | * refer to a <code>Boolean</code>, <code>Double</code>, <code>String</code>, |
|
72 | * node-set (<code>List</code>) or individual XML node. |
|
73 | * </p> |
|
74 | * |
|
75 | * <p> |
|
76 | * When a variable is bound to a node-set, the |
|
77 | * actual Java object returned should be a <code>java.util.List</code> |
|
78 | * containing XML nodes from the object-model (e.g. dom4j, JDOM, DOM, etc.) |
|
79 | * being used with the XPath. |
|
80 | * </p> |
|
81 | * |
|
82 | * <p> |
|
83 | * A variable may validly be assigned the <code>null</code> value, |
|
84 | * but an unbound variable (one that this context does not know about) |
|
85 | * should cause an {@link UnresolvableException} to be thrown. |
|
86 | * </p> |
|
87 | * |
|
88 | * @see SimpleVariableContext |
|
89 | * @see NamespaceContext |
|
90 | * |
|
91 | * @author <a href="mailto:bob@werken.com">bob mcwhirter</a> |
|
92 | * @author <a href="mailto:jstrachan@apache.org">James Strachan</a> |
|
93 | */ |
|
94 | public interface VariableContext |
|
95 | { |
|
96 | /** An implementation should return the value of an XPath variable |
|
97 | * based on the namespace URI and local name of the variable-reference |
|
98 | * expression. |
|
99 | * |
|
100 | * <p> |
|
101 | * It must not use the prefix parameter to select a variable, |
|
102 | * because a prefix could be bound to any namespace; the prefix parameter |
|
103 | * could be used in debugging output or other generated information. |
|
104 | * The prefix may otherwise be ignored. |
|
105 | * </p> |
|
106 | * |
|
107 | * @param namespaceURI the namespace URI to which the prefix parameter |
|
108 | * is bound in the XPath expression. If the variable |
|
109 | * reference expression had no prefix, the namespace |
|
110 | * URI is <code>null</code>. |
|
111 | * @param prefix the prefix that was used in the variable reference |
|
112 | * expression; this value is ignored and has no effect |
|
113 | * @param localName the local name of the variable-reference |
|
114 | * expression. If there is no prefix, then this is |
|
115 | * the whole name of the variable. |
|
116 | * |
|
117 | * @return the variable's value (which can be <code>null</code>) |
|
118 | * @throws UnresolvableException when the variable cannot be resolved |
|
119 | */ |
|
120 | public Object getVariableValue( String namespaceURI, |
|
121 | String prefix, |
|
122 | String localName ) |
|
123 | throws UnresolvableException; |
|
124 | } |