001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 /*
019 * $Id: FunctionOneArg.java 468655 2006-10-28 07:12:06Z minchau $
020 */
021 package org.apache.xpath.functions;
022
023 import org.apache.xalan.res.XSLMessages;
024 import org.apache.xpath.Expression;
025 import org.apache.xpath.ExpressionOwner;
026 import org.apache.xpath.XPathVisitor;
027
028 /**
029 * Base class for functions that accept one argument.
030 * @xsl.usage advanced
031 */
032 public class FunctionOneArg extends Function implements ExpressionOwner
033 {
034 static final long serialVersionUID = -5180174180765609758L;
035
036 /** The first argument passed to the function (at index 0).
037 * @serial */
038 Expression m_arg0;
039
040 /**
041 * Return the first argument passed to the function (at index 0).
042 *
043 * @return An expression that represents the first argument passed to the
044 * function.
045 */
046 public Expression getArg0()
047 {
048 return m_arg0;
049 }
050
051 /**
052 * Set an argument expression for a function. This method is called by the
053 * XPath compiler.
054 *
055 * @param arg non-null expression that represents the argument.
056 * @param argNum The argument number index.
057 *
058 * @throws WrongNumberArgsException If the argNum parameter is greater than 0.
059 */
060 public void setArg(Expression arg, int argNum)
061 throws WrongNumberArgsException
062 {
063
064 if (0 == argNum)
065 {
066 m_arg0 = arg;
067 arg.exprSetParent(this);
068 }
069 else
070 reportWrongNumberArgs();
071 }
072
073 /**
074 * Check that the number of arguments passed to this function is correct.
075 *
076 *
077 * @param argNum The number of arguments that is being passed to the function.
078 *
079 * @throws WrongNumberArgsException
080 */
081 public void checkNumberArgs(int argNum) throws WrongNumberArgsException
082 {
083 if (argNum != 1)
084 reportWrongNumberArgs();
085 }
086
087 /**
088 * Constructs and throws a WrongNumberArgException with the appropriate
089 * message for this function object.
090 *
091 * @throws WrongNumberArgsException
092 */
093 protected void reportWrongNumberArgs() throws WrongNumberArgsException {
094 throw new WrongNumberArgsException(XSLMessages.createXPATHMessage("one", null));
095 }
096
097 /**
098 * Tell if this expression or it's subexpressions can traverse outside
099 * the current subtree.
100 *
101 * @return true if traversal outside the context node's subtree can occur.
102 */
103 public boolean canTraverseOutsideSubtree()
104 {
105 return m_arg0.canTraverseOutsideSubtree();
106 }
107
108 /**
109 * This function is used to fixup variables from QNames to stack frame
110 * indexes at stylesheet build time.
111 * @param vars List of QNames that correspond to variables. This list
112 * should be searched backwards for the first qualified name that
113 * corresponds to the variable reference qname. The position of the
114 * QName in the vector from the start of the vector will be its position
115 * in the stack frame (but variables above the globalsTop value will need
116 * to be offset to the current stack frame).
117 */
118 public void fixupVariables(java.util.Vector vars, int globalsSize)
119 {
120 if(null != m_arg0)
121 m_arg0.fixupVariables(vars, globalsSize);
122 }
123
124 /**
125 * @see org.apache.xpath.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
126 */
127 public void callArgVisitors(XPathVisitor visitor)
128 {
129 if(null != m_arg0)
130 m_arg0.callVisitors(this, visitor);
131 }
132
133
134 /**
135 * @see ExpressionOwner#getExpression()
136 */
137 public Expression getExpression()
138 {
139 return m_arg0;
140 }
141
142 /**
143 * @see ExpressionOwner#setExpression(Expression)
144 */
145 public void setExpression(Expression exp)
146 {
147 exp.exprSetParent(this);
148 m_arg0 = exp;
149 }
150
151 /**
152 * @see Expression#deepEquals(Expression)
153 */
154 public boolean deepEquals(Expression expr)
155 {
156 if(!super.deepEquals(expr))
157 return false;
158
159 if(null != m_arg0)
160 {
161 if(null == ((FunctionOneArg)expr).m_arg0)
162 return false;
163
164 if(!m_arg0.deepEquals(((FunctionOneArg)expr).m_arg0))
165 return false;
166 }
167 else if(null != ((FunctionOneArg)expr).m_arg0)
168 return false;
169
170 return true;
171 }
172
173
174 }