| 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 |