1 /* 2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultLocationPath.java,v 1.26 2005/05/16 10:46:43 elharo Exp $ 3 * $Revision: 1.26 $ 4 * $Date: 2005/05/16 10:46:43 $ 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: DefaultLocationPath.java,v 1.26 2005/05/16 10:46:43 elharo Exp $ 60 */ 61 package org.jaxen.expr; 62 63 import java.util.ArrayList; 64 import java.util.Collections; 65 import java.util.Iterator; 66 import java.util.LinkedList; 67 import java.util.List; 68 69 import org.jaxen.Context; 70 import org.jaxen.ContextSupport; 71 import org.jaxen.JaxenException; 72 73 abstract class DefaultLocationPath extends DefaultExpr implements LocationPath 74 { 75 private List steps; 76 77 /*** 78 * Create a new empty location path. 79 */ 80 DefaultLocationPath() 81 { 82 this.steps = new LinkedList(); 83 } 84 85 public void addStep(Step step) 86 { 87 getSteps().add(step); 88 } 89 90 public List getSteps() 91 { 92 return this.steps; 93 } 94 95 public Expr simplify() 96 { 97 Iterator stepIter = getSteps().iterator(); 98 Step eachStep = null; 99 while (stepIter.hasNext()) 100 { 101 eachStep = (Step) stepIter.next(); 102 eachStep.simplify(); 103 } 104 return this; 105 } 106 107 public String getText() 108 { 109 StringBuffer buf = new StringBuffer(); 110 Iterator stepIter = getSteps().iterator(); 111 while (stepIter.hasNext()) 112 { 113 buf.append(((Step) stepIter.next()).getText()); 114 if (stepIter.hasNext()) 115 { 116 buf.append("/"); 117 } 118 } 119 return buf.toString(); 120 } 121 122 public String toString() 123 { 124 StringBuffer buf = new StringBuffer(); 125 Iterator stepIter = getSteps().iterator(); 126 while (stepIter.hasNext()) 127 { 128 buf.append(stepIter.next().toString()); 129 if (stepIter.hasNext()) 130 { 131 buf.append("/"); 132 } 133 } 134 return buf.toString(); 135 } 136 137 public boolean isAbsolute() 138 { 139 return false; 140 } 141 142 public Object evaluate(Context context) throws JaxenException 143 { 144 List nodeSet = context.getNodeSet(); 145 List contextNodeSet = new ArrayList(nodeSet.size()); 146 contextNodeSet.addAll(nodeSet); 147 ContextSupport support = context.getContextSupport(); 148 Context stepContext = new Context(support); 149 Iterator stepIter = getSteps().iterator(); 150 while ( stepIter.hasNext() ) 151 { 152 Step eachStep = (Step) stepIter.next(); 153 stepContext.setNodeSet(contextNodeSet); 154 contextNodeSet = eachStep.evaluate(stepContext); 155 // now we need to reverse the list if this is a reverse axis 156 if (isReverseAxis(eachStep)) { 157 Collections.reverse(contextNodeSet); 158 } 159 } 160 161 if (getSteps().size() > 1) { 162 Collections.sort(contextNodeSet, new NodeComparator(support.getNavigator())); 163 } 164 165 return contextNodeSet; 166 } 167 168 private boolean isReverseAxis(Step step) { 169 170 int axis = step.getAxis(); 171 return axis == org.jaxen.saxpath.Axis.PRECEDING 172 || axis == org.jaxen.saxpath.Axis.PRECEDING_SIBLING 173 || axis == org.jaxen.saxpath.Axis.ANCESTOR 174 || axis == org.jaxen.saxpath.Axis.ANCESTOR_OR_SELF; 175 } 176 177 } 178