Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||||||
IdFunction |
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| 4.0;4 |
1 | /* |
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2 | * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/IdFunction.java,v 1.12 2005/09/23 13:58:46 elharo Exp $ |
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3 | * $Revision: 1.12 $ |
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4 | * $Date: 2005/09/23 13:58:46 $ |
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5 | * |
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6 | * ==================================================================== |
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7 | * |
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8 | * Copyright (C) 2000-2002 bob mcwhirter & James Strachan. |
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9 | * All rights reserved. |
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10 | * |
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11 | * Redistribution and use in source and binary forms, with or without |
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12 | * modification, are permitted provided that the following conditions |
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13 | * are met: |
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14 | * |
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15 | * 1. Redistributions of source code must retain the above copyright |
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16 | * notice, this list of conditions, and the following disclaimer. |
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17 | * |
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18 | * 2. Redistributions in binary form must reproduce the above copyright |
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19 | * notice, this list of conditions, and the disclaimer that follows |
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20 | * these conditions in the documentation and/or other materials |
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21 | * provided with the distribution. |
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22 | * |
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23 | * 3. The name "Jaxen" must not be used to endorse or promote products |
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24 | * derived from this software without prior written permission. For |
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25 | * written permission, please contact license@jaxen.org. |
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26 | * |
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27 | * 4. Products derived from this software may not be called "Jaxen", nor |
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28 | * may "Jaxen" appear in their name, without prior written permission |
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29 | * from the Jaxen Project Management (pm@jaxen.org). |
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30 | * |
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31 | * In addition, we request (but do not require) that you include in the |
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32 | * end-user documentation provided with the redistribution and/or in the |
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33 | * software itself an acknowledgement equivalent to the following: |
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34 | * "This product includes software developed by the |
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35 | * Jaxen Project <http://www.jaxen.org/>." |
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36 | * Alternatively, the acknowledgment may be graphical using the logos |
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37 | * available at http://www.jaxen.org/ |
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38 | * |
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39 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
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40 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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41 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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42 | * DISCLAIMED. IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT |
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43 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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44 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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45 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
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46 | * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
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47 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
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48 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
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49 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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50 | * SUCH DAMAGE. |
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51 | * |
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52 | * ==================================================================== |
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53 | * This software consists of voluntary contributions made by many |
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54 | * individuals on behalf of the Jaxen Project and was originally |
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55 | * created by bob mcwhirter <bob@werken.com> and |
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56 | * James Strachan <jstrachan@apache.org>. For more information on the |
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57 | * Jaxen Project, please see <http://www.jaxen.org/>. |
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58 | * |
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59 | * $Id: IdFunction.java,v 1.12 2005/09/23 13:58:46 elharo Exp $ |
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60 | */ |
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61 | ||
62 | package org.jaxen.function; |
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63 | ||
64 | import java.util.ArrayList; |
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65 | import java.util.Collections; |
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66 | import java.util.Iterator; |
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67 | import java.util.List; |
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68 | import java.util.StringTokenizer; |
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69 | ||
70 | import org.jaxen.Context; |
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71 | import org.jaxen.Function; |
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72 | import org.jaxen.FunctionCallException; |
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73 | import org.jaxen.Navigator; |
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74 | ||
75 | /** |
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76 | * <p><b>4.1</b> <code><i>node-set</i> id(<i>object</i>)</code> </p> |
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77 | * |
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78 | * <p>The <b>id</b> function returns a <code>List</code> |
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79 | * of all the elements in the context document that have an ID |
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80 | * matching one of a specified list of IDs. How an attribute is determined |
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81 | * to be of type ID depends on the navigator, but it normally requires that |
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82 | * the attribute be declared to have type ID in the DTD. |
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83 | * </p> |
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84 | * |
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85 | * <p> |
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86 | * There should be no more than one element in any document with a |
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87 | * certain ID. However, if there are multiple such elements--i.e. if |
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88 | * there are duplicate IDs--then this function selects only the first element |
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89 | * in document order with the specified ID. |
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90 | * </p> |
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91 | * |
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92 | * @author Erwin Bolwidt (ejb @ klomp.org) |
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93 | * @author J\u00e9r\u00f4me N\u00e8gre (jerome.negre @ e-xmlmedia.fr) |
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94 | * |
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95 | * @see <a href="http://www.w3.org/TR/xpath#function-id" target="_top">Section 4.1 of the XPath Specification</a> |
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96 | */ |
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97 | public class IdFunction implements Function |
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98 | { |
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99 | ||
100 | /** |
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101 | * Create a new <code>IdFunction</code> object. |
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102 | */ |
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103 | 294 | public IdFunction() {} |
104 | ||
105 | /** |
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106 | * Returns a list of the nodes with the specified IDs. |
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107 | * |
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108 | * @param context the context at the point in the |
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109 | * expression when the function is called |
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110 | * @param args a list with exactly one item which is either a string |
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111 | * a node-set |
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112 | * |
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113 | * @return a <code>List</code> containing the first node in document |
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114 | * with each of the specified IDs; or |
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115 | * an empty list if there are no such nodes |
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116 | * |
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117 | * @throws FunctionCallException if <code>args</code> has more or less than one item |
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118 | */ |
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119 | public Object call(Context context, List args) throws FunctionCallException |
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120 | { |
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121 | 42 | if ( args.size() == 1 ) { |
122 | 30 | return evaluate( context.getNodeSet(), |
123 | args.get(0), context.getNavigator() ); |
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124 | } |
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125 | ||
126 | 12 | throw new FunctionCallException( "id() requires one argument" ); |
127 | } |
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128 | ||
129 | /** |
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130 | * Returns a list of the nodes with the specified IDs. |
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131 | * |
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132 | * @param contextNodes the context node-set. The first item in this list |
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133 | * determines the document in which the search is performed. |
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134 | * @param arg the ID or IDs to search for |
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135 | * @param nav the navigator used to calculate string-values and search |
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136 | * by ID |
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137 | * |
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138 | * @return a <code>List</code> containing the first node in document |
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139 | * with each of the specified IDs; or |
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140 | * an empty list if there are no such nodes |
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141 | * |
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142 | */ |
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143 | public static List evaluate(List contextNodes, Object arg, Navigator nav) |
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144 | { |
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145 | 48 | if (contextNodes.size() == 0) return Collections.EMPTY_LIST; |
146 | ||
147 | 48 | List nodes = new ArrayList(); |
148 | ||
149 | 48 | Object contextNode = contextNodes.get(0); |
150 | ||
151 | 48 | if (arg instanceof List) { |
152 | 6 | Iterator iter = ((List)arg).iterator(); |
153 | 24 | while (iter.hasNext()) { |
154 | 18 | String id = StringFunction.evaluate(iter.next(), nav); |
155 | 18 | nodes.addAll( evaluate( contextNodes, id, nav ) ); |
156 | } |
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157 | } |
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158 | else { |
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159 | 42 | String ids = StringFunction.evaluate(arg, nav); |
160 | 42 | StringTokenizer tok = new StringTokenizer(ids, " \t\n\r"); |
161 | 84 | while (tok.hasMoreTokens()) { |
162 | 42 | String id = tok.nextToken(); |
163 | 42 | Object node = nav.getElementById(contextNode, id); |
164 | 42 | if (node != null) { |
165 | 24 | nodes.add(node); |
166 | } |
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167 | } |
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168 | } |
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169 | 48 | return nodes; |
170 | } |
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171 | ||
172 | } |
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173 |