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: Function3Args.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.xpath.Expression;
25 import org.apache.xpath.ExpressionOwner;
26 import org.apache.xpath.XPathVisitor;
27 
28 /**
29  * Base class for functions that accept three arguments.
30  * @xsl.usage advanced
31  */
32 public class Function3Args extends Function2Args
33 {
34     static final long serialVersionUID = 7915240747161506646L;
35 
36   /** The third argument passed to the function (at index 2).
37    *  @serial  */
38   Expression m_arg2;
39 
40   /**
41    * Return the third argument passed to the function (at index 2).
42    *
43    * @return An expression that represents the third argument passed to the
44    *         function.
45    */
getArg2()46   public Expression getArg2()
47   {
48     return m_arg2;
49   }
50 
51   /**
52    * This function is used to fixup variables from QNames to stack frame
53    * indexes at stylesheet build time.
54    * @param vars List of QNames that correspond to variables.  This list
55    * should be searched backwards for the first qualified name that
56    * corresponds to the variable reference qname.  The position of the
57    * QName in the vector from the start of the vector will be its position
58    * in the stack frame (but variables above the globalsTop value will need
59    * to be offset to the current stack frame).
60    */
fixupVariables(java.util.Vector vars, int globalsSize)61   public void fixupVariables(java.util.Vector vars, int globalsSize)
62   {
63     super.fixupVariables(vars, globalsSize);
64     if(null != m_arg2)
65       m_arg2.fixupVariables(vars, globalsSize);
66   }
67 
68   /**
69    * Set an argument expression for a function.  This method is called by the
70    * XPath compiler.
71    *
72    * @param arg non-null expression that represents the argument.
73    * @param argNum The argument number index.
74    *
75    * @throws WrongNumberArgsException If the argNum parameter is greater than 2.
76    */
setArg(Expression arg, int argNum)77   public void setArg(Expression arg, int argNum)
78           throws WrongNumberArgsException
79   {
80 
81     if (argNum < 2)
82       super.setArg(arg, argNum);
83     else if (2 == argNum)
84     {
85       m_arg2 = arg;
86       arg.exprSetParent(this);
87     }
88     else
89 		  reportWrongNumberArgs();
90   }
91 
92   /**
93    * Check that the number of arguments passed to this function is correct.
94    *
95    *
96    * @param argNum The number of arguments that is being passed to the function.
97    *
98    * @throws WrongNumberArgsException
99    */
checkNumberArgs(int argNum)100   public void checkNumberArgs(int argNum) throws WrongNumberArgsException
101   {
102     if (argNum != 3)
103       reportWrongNumberArgs();
104   }
105 
106   /**
107    * Constructs and throws a WrongNumberArgException with the appropriate
108    * message for this function object.
109    *
110    * @throws WrongNumberArgsException
111    */
reportWrongNumberArgs()112   protected void reportWrongNumberArgs() throws WrongNumberArgsException {
113       throw new WrongNumberArgsException(XSLMessages.createXPATHMessage("three", null));
114   }
115 
116   /**
117    * Tell if this expression or it's subexpressions can traverse outside
118    * the current subtree.
119    *
120    * @return true if traversal outside the context node's subtree can occur.
121    */
canTraverseOutsideSubtree()122    public boolean canTraverseOutsideSubtree()
123    {
124     return super.canTraverseOutsideSubtree()
125     ? true : m_arg2.canTraverseOutsideSubtree();
126    }
127 
128   class Arg2Owner implements ExpressionOwner
129   {
130     /**
131      * @see ExpressionOwner#getExpression()
132      */
getExpression()133     public Expression getExpression()
134     {
135       return m_arg2;
136     }
137 
138 
139     /**
140      * @see ExpressionOwner#setExpression(Expression)
141      */
setExpression(Expression exp)142     public void setExpression(Expression exp)
143     {
144     	exp.exprSetParent(Function3Args.this);
145     	m_arg2 = exp;
146     }
147   }
148 
149 
150   /**
151    * @see org.apache.xpath.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
152    */
callArgVisitors(XPathVisitor visitor)153   public void callArgVisitors(XPathVisitor visitor)
154   {
155   	super.callArgVisitors(visitor);
156   	if(null != m_arg2)
157   		m_arg2.callVisitors(new Arg2Owner(), visitor);
158   }
159 
160   /**
161    * @see Expression#deepEquals(Expression)
162    */
deepEquals(Expression expr)163   public boolean deepEquals(Expression expr)
164   {
165   	if(!super.deepEquals(expr))
166   		return false;
167 
168   	if(null != m_arg2)
169   	{
170   		if(null == ((Function3Args)expr).m_arg2)
171   			return false;
172 
173   		if(!m_arg2.deepEquals(((Function3Args)expr).m_arg2))
174   			return false;
175   	}
176   	else if (null != ((Function3Args)expr).m_arg2)
177   		return false;
178 
179   	return true;
180   }
181 
182 
183 }
184