1 /* 2 * $Header$ 3 * $Revision$ 4 * $Date$ 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 * $Id$ 46 */ 47 48 49 package org.jaxen.function; 50 51 import java.util.List; 52 53 import org.jaxen.Context; 54 import org.jaxen.Function; 55 import org.jaxen.FunctionCallException; 56 import org.jaxen.Navigator; 57 58 /** 59 * <p><b>4.1</b> <code><i>string</i> name(<i>node-set?</i>)</code> </p> 60 * 61 * 62 * <blockquote cite="http://www.w3.org/TR/xpath"> 63 * The <b>name</b> function returns a string containing a QName representing 64 * the expanded-name of the node in the argument node-set that is first in document order. 65 * The QName must represent the expanded-name with respect to the namespace declarations 66 * in effect on the node whose expanded-name is being represented. Typically, this will 67 * be the QName that occurred in the XML source....If 68 * the argument node-set is empty or the first node has 69 * no expanded-name, an empty string is returned. 70 * If the argument it omitted, it defaults to a node-set with the context node as its only member. 71 * </blockquote> 72 * 73 * @author bob mcwhirter (bob @ werken.com) 74 * 75 * @see <a href="https://www.w3.org/TR/xpath#function-name" target="_top">Section 4.1 of the XPath Specification</a> 76 */ 77 public class NameFunction implements Function 78 { 79 80 81 /** 82 * Create a new <code>NameFunction</code> object. 83 */ 84 public NameFunction() {} 85 86 /** 87 * Returns the name of the specified node or the name of the context node if 88 * no arguments are provided. 89 * 90 * @param context the context at the point in the 91 * expression where the function is called 92 * @param args a <code>List</code> containing zero or one items 93 * 94 * @return a <code>String</code> containing the name 95 * 96 * @throws FunctionCallException if <code>args</code> has more than one item 97 */ 98 public Object call(Context context, 99 List args) throws FunctionCallException 100 { 101 if ( args.size() == 0 ) 102 { 103 return evaluate( context.getNodeSet(), 104 context.getNavigator() ); 105 } 106 107 if ( args.size() == 1 ) 108 { 109 return evaluate( args, 110 context.getNavigator() ); 111 } 112 113 throw new FunctionCallException( "name() requires zero or one argument." ); 114 } 115 116 /** 117 * Returns the name of <code>list.get(0)</code> 118 * 119 * @param list a list of nodes 120 * @param nav the <code>Navigator</code> used to retrieve the name 121 * 122 * @return the name of <code>list.get(0)</code> 123 * 124 * @throws FunctionCallException if <code>list.get(0)</code> is not a node 125 */ 126 public static String evaluate(List list, 127 Navigator nav) throws FunctionCallException 128 { 129 if ( ! list.isEmpty() ) 130 { 131 Object first = list.get(0); 132 133 if (first instanceof List) 134 { 135 return evaluate( (List) first, 136 nav ); 137 } 138 else if ( nav.isElement( first ) ) 139 { 140 return nav.getElementQName( first ); 141 } 142 else if ( nav.isAttribute( first ) ) 143 { 144 return nav.getAttributeQName( first ); 145 } 146 else if ( nav.isProcessingInstruction( first ) ) 147 { 148 return nav.getProcessingInstructionTarget( first ); 149 } 150 else if ( nav.isNamespace( first ) ) 151 { 152 return nav.getNamespacePrefix( first ); 153 } 154 else if ( nav.isDocument( first ) ) 155 { 156 return ""; 157 } 158 else if ( nav.isComment( first ) ) 159 { 160 return ""; 161 } 162 else if ( nav.isText( first ) ) 163 { 164 return ""; 165 } 166 else { 167 throw new FunctionCallException("The argument to the name function must be a node-set"); 168 } 169 } 170 171 return ""; 172 173 } 174 175 }