1 /* 2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/LangFunction.java,v 1.6 2005/04/16 09:54:50 elharo Exp $ 3 * $Revision: 1.6 $ 4 * $Date: 2005/04/16 09:54:50 $ 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: LangFunction.java,v 1.6 2005/04/16 09:54:50 elharo Exp $ 60 */ 61 62 63 package org.jaxen.function; 64 65 import java.util.Iterator; 66 import java.util.List; 67 68 import org.jaxen.Context; 69 import org.jaxen.Function; 70 import org.jaxen.FunctionCallException; 71 import org.jaxen.Navigator; 72 import org.jaxen.UnsupportedAxisException; 73 74 /*** 75 * <p><b>4.3</b> <code><i>boolean</i> lang(<i>string</i>)</code> 76 * 77 * @author Attila Szegedi (szegedia @ freemail.hu) 78 */ 79 public class LangFunction implements Function 80 { 81 private static final String LANG_LOCALNAME = "lang"; 82 private static final String XMLNS_URI = 83 "http://www.w3.org/XML/1998/namespace"; 84 85 86 public Object call(Context context, 87 List args) throws FunctionCallException 88 { 89 if (args.size() != 1) { 90 throw new FunctionCallException("lang() requires exactly one argument."); 91 } 92 93 Object arg = args.get(0); 94 95 try { 96 return evaluate(context.getNodeSet(), arg, context.getNavigator() ); 97 } 98 catch(UnsupportedAxisException e) { 99 throw new FunctionCallException("Can't evaluate lang()", 100 e); 101 } 102 103 } 104 105 private static Boolean evaluate(List contextNodes, Object lang, Navigator nav) 106 throws UnsupportedAxisException 107 { 108 return Boolean.valueOf( 109 evaluate(contextNodes.get(0), 110 StringFunction.evaluate(lang, nav), nav) 111 ); 112 } 113 114 private static boolean evaluate(Object node, String lang, Navigator nav) 115 throws UnsupportedAxisException 116 { 117 118 Object element = node; 119 if (! nav.isElement(element)) { 120 element = nav.getParentNode(node); 121 } 122 while (element != null && nav.isElement(element)) 123 { 124 Iterator attrs = nav.getAttributeAxisIterator(element); 125 while(attrs.hasNext()) 126 { 127 Object attr = attrs.next(); 128 if(LANG_LOCALNAME.equals(nav.getAttributeName(attr)) && 129 XMLNS_URI.equals(nav.getAttributeNamespaceUri(attr))) 130 { 131 return 132 isSublang(nav.getAttributeStringValue(attr), lang); 133 } 134 } 135 element = nav.getParentNode(element); 136 } 137 return false; 138 } 139 140 private static boolean isSublang(String sublang, String lang) 141 { 142 if(sublang.equalsIgnoreCase(lang)) 143 { 144 return true; 145 } 146 int ll = lang.length(); 147 return 148 sublang.length() > ll && 149 sublang.charAt(ll) == '-' && 150 sublang.substring(0, ll).equalsIgnoreCase(lang); 151 } 152 } 153