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