Coverage Report - org.jaxen.function.IdFunction
 
Classes in this File Line Coverage Branch Coverage Complexity
IdFunction
100%
23/23
100%
6/6
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