Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
IdFunction |
|
| 4.0;4 |
1 | /* | |
2 | * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/IdFunction.java,v 1.13 2006/02/05 21:47:41 elharo Exp $ | |
3 | * $Revision: 1.13 $ | |
4 | * $Date: 2006/02/05 21:47:41 $ | |
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: IdFunction.java,v 1.13 2006/02/05 21:47:41 elharo Exp $ | |
46 | */ | |
47 | ||
48 | package org.jaxen.function; | |
49 | ||
50 | import java.util.ArrayList; | |
51 | import java.util.Collections; | |
52 | import java.util.Iterator; | |
53 | import java.util.List; | |
54 | import java.util.StringTokenizer; | |
55 | ||
56 | import org.jaxen.Context; | |
57 | import org.jaxen.Function; | |
58 | import org.jaxen.FunctionCallException; | |
59 | import org.jaxen.Navigator; | |
60 | ||
61 | /** | |
62 | * <p><b>4.1</b> <code><i>node-set</i> id(<i>object</i>)</code> </p> | |
63 | * | |
64 | * <p>The <b>id</b> function returns a <code>List</code> | |
65 | * of all the elements in the context document that have an ID | |
66 | * matching one of a specified list of IDs. How an attribute is determined | |
67 | * to be of type ID depends on the navigator, but it normally requires that | |
68 | * the attribute be declared to have type ID in the DTD. | |
69 | * </p> | |
70 | * | |
71 | * <p> | |
72 | * There should be no more than one element in any document with a | |
73 | * certain ID. However, if there are multiple such elements--i.e. if | |
74 | * there are duplicate IDs--then this function selects only the first element | |
75 | * in document order with the specified ID. | |
76 | * </p> | |
77 | * | |
78 | * @author Erwin Bolwidt (ejb @ klomp.org) | |
79 | * @author J\u00e9r\u00f4me N\u00e8gre (jerome.negre @ e-xmlmedia.fr) | |
80 | * | |
81 | * @see <a href="http://www.w3.org/TR/xpath#function-id" target="_top">Section 4.1 of the XPath Specification</a> | |
82 | */ | |
83 | public class IdFunction implements Function | |
84 | { | |
85 | ||
86 | /** | |
87 | * Create a new <code>IdFunction</code> object. | |
88 | */ | |
89 | 106 | public IdFunction() {} |
90 | ||
91 | /** | |
92 | * Returns a list of the nodes with the specified IDs. | |
93 | * | |
94 | * @param context the context at the point in the | |
95 | * expression when the function is called | |
96 | * @param args a list with exactly one item which is either a string | |
97 | * a node-set | |
98 | * | |
99 | * @return a <code>List</code> containing the first node in document | |
100 | * with each of the specified IDs; or | |
101 | * an empty list if there are no such nodes | |
102 | * | |
103 | * @throws FunctionCallException if <code>args</code> has more or less than one item | |
104 | */ | |
105 | public Object call(Context context, List args) throws FunctionCallException | |
106 | { | |
107 | 14 | if ( args.size() == 1 ) { |
108 | 10 | return evaluate( context.getNodeSet(), |
109 | args.get(0), context.getNavigator() ); | |
110 | } | |
111 | ||
112 | 4 | throw new FunctionCallException( "id() requires one argument" ); |
113 | } | |
114 | ||
115 | /** | |
116 | * Returns a list of the nodes with the specified IDs. | |
117 | * | |
118 | * @param contextNodes the context node-set. The first item in this list | |
119 | * determines the document in which the search is performed. | |
120 | * @param arg the ID or IDs to search for | |
121 | * @param nav the navigator used to calculate string-values and search | |
122 | * by ID | |
123 | * | |
124 | * @return a <code>List</code> containing the first node in document | |
125 | * with each of the specified IDs; or | |
126 | * an empty list if there are no such nodes | |
127 | * | |
128 | */ | |
129 | public static List evaluate(List contextNodes, Object arg, Navigator nav) | |
130 | { | |
131 | 16 | if (contextNodes.size() == 0) return Collections.EMPTY_LIST; |
132 | ||
133 | 16 | List nodes = new ArrayList(); |
134 | ||
135 | 16 | Object contextNode = contextNodes.get(0); |
136 | ||
137 | 16 | if (arg instanceof List) { |
138 | 2 | Iterator iter = ((List)arg).iterator(); |
139 | 8 | while (iter.hasNext()) { |
140 | 6 | String id = StringFunction.evaluate(iter.next(), nav); |
141 | 6 | nodes.addAll( evaluate( contextNodes, id, nav ) ); |
142 | 6 | } |
143 | 2 | } |
144 | else { | |
145 | 14 | String ids = StringFunction.evaluate(arg, nav); |
146 | 14 | StringTokenizer tok = new StringTokenizer(ids, " \t\n\r"); |
147 | 28 | while (tok.hasMoreTokens()) { |
148 | 14 | String id = tok.nextToken(); |
149 | 14 | Object node = nav.getElementById(contextNode, id); |
150 | 14 | if (node != null) { |
151 | 8 | nodes.add(node); |
152 | } | |
153 | 14 | } |
154 | } | |
155 | 16 | return nodes; |
156 | } | |
157 | ||
158 | } | |
159 |