1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 /* 19 * $Id: FunctionDef1Arg.java 468655 2006-10-28 07:12:06Z minchau $ 20 */ 21 package org.apache.xpath.functions; 22 23 import org.apache.xalan.res.XSLMessages; 24 import org.apache.xml.dtm.DTM; 25 import org.apache.xml.utils.XMLString; 26 import org.apache.xpath.XPathContext; 27 import org.apache.xpath.objects.XString; 28 import org.apache.xpath.res.XPATHErrorResources; 29 30 /** 31 * Base class for functions that accept one argument that can be defaulted if 32 * not specified. 33 * @xsl.usage advanced 34 */ 35 public class FunctionDef1Arg extends FunctionOneArg 36 { 37 static final long serialVersionUID = 2325189412814149264L; 38 39 /** 40 * Execute the first argument expression that is expected to return a 41 * nodeset. If the argument is null, then return the current context node. 42 * 43 * @param xctxt Runtime XPath context. 44 * 45 * @return The first node of the executed nodeset, or the current context 46 * node if the first argument is null. 47 * 48 * @throws javax.xml.transform.TransformerException if an error occurs while 49 * executing the argument expression. 50 */ getArg0AsNode(XPathContext xctxt)51 protected int getArg0AsNode(XPathContext xctxt) 52 throws javax.xml.transform.TransformerException 53 { 54 55 return (null == m_arg0) 56 ? xctxt.getCurrentNode() : m_arg0.asNode(xctxt); 57 } 58 59 /** 60 * Tell if the expression is a nodeset expression. 61 * @return true if the expression can be represented as a nodeset. 62 */ Arg0IsNodesetExpr()63 public boolean Arg0IsNodesetExpr() 64 { 65 return (null == m_arg0) ? true : m_arg0.isNodesetExpr(); 66 } 67 68 /** 69 * Execute the first argument expression that is expected to return a 70 * string. If the argument is null, then get the string value from the 71 * current context node. 72 * 73 * @param xctxt Runtime XPath context. 74 * 75 * @return The string value of the first argument, or the string value of the 76 * current context node if the first argument is null. 77 * 78 * @throws javax.xml.transform.TransformerException if an error occurs while 79 * executing the argument expression. 80 */ getArg0AsString(XPathContext xctxt)81 protected XMLString getArg0AsString(XPathContext xctxt) 82 throws javax.xml.transform.TransformerException 83 { 84 if(null == m_arg0) 85 { 86 int currentNode = xctxt.getCurrentNode(); 87 if(DTM.NULL == currentNode) 88 return XString.EMPTYSTRING; 89 else 90 { 91 DTM dtm = xctxt.getDTM(currentNode); 92 return dtm.getStringValue(currentNode); 93 } 94 95 } 96 else 97 return m_arg0.execute(xctxt).xstr(); 98 } 99 100 /** 101 * Execute the first argument expression that is expected to return a 102 * number. If the argument is null, then get the number value from the 103 * current context node. 104 * 105 * @param xctxt Runtime XPath context. 106 * 107 * @return The number value of the first argument, or the number value of the 108 * current context node if the first argument is null. 109 * 110 * @throws javax.xml.transform.TransformerException if an error occurs while 111 * executing the argument expression. 112 */ getArg0AsNumber(XPathContext xctxt)113 protected double getArg0AsNumber(XPathContext xctxt) 114 throws javax.xml.transform.TransformerException 115 { 116 117 if(null == m_arg0) 118 { 119 int currentNode = xctxt.getCurrentNode(); 120 if(DTM.NULL == currentNode) 121 return 0; 122 else 123 { 124 DTM dtm = xctxt.getDTM(currentNode); 125 XMLString str = dtm.getStringValue(currentNode); 126 return str.toDouble(); 127 } 128 129 } 130 else 131 return m_arg0.execute(xctxt).num(); 132 } 133 134 /** 135 * Check that the number of arguments passed to this function is correct. 136 * 137 * @param argNum The number of arguments that is being passed to the function. 138 * 139 * @throws WrongNumberArgsException if the number of arguments is not 0 or 1. 140 */ checkNumberArgs(int argNum)141 public void checkNumberArgs(int argNum) throws WrongNumberArgsException 142 { 143 if (argNum > 1) 144 reportWrongNumberArgs(); 145 } 146 147 /** 148 * Constructs and throws a WrongNumberArgException with the appropriate 149 * message for this function object. 150 * 151 * @throws WrongNumberArgsException 152 */ reportWrongNumberArgs()153 protected void reportWrongNumberArgs() throws WrongNumberArgsException { 154 throw new WrongNumberArgsException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_ZERO_OR_ONE, null)); //"0 or 1"); 155 } 156 157 /** 158 * Tell if this expression or it's subexpressions can traverse outside 159 * the current subtree. 160 * 161 * @return true if traversal outside the context node's subtree can occur. 162 */ canTraverseOutsideSubtree()163 public boolean canTraverseOutsideSubtree() 164 { 165 return (null == m_arg0) ? false : super.canTraverseOutsideSubtree(); 166 } 167 } 168