1 /*
2  * reserved comment block
3  * DO NOT REMOVE OR ALTER!
4  */
5 /*
6  * Licensed to the Apache Software Foundation (ASF) under one or more
7  * contributor license agreements.  See the NOTICE file distributed with
8  * this work for additional information regarding copyright ownership.
9  * The ASF licenses this file to You under the Apache License, Version 2.0
10  * (the "License"); you may not use this file except in compliance with
11  * the License.  You may obtain a copy of the License at
12  *
13  *      http://www.apache.org/licenses/LICENSE-2.0
14  *
15  * Unless required by applicable law or agreed to in writing, software
16  * distributed under the License is distributed on an "AS IS" BASIS,
17  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18  * See the License for the specific language governing permissions and
19  * limitations under the License.
20  */
21 
22 package com.sun.org.apache.xalan.internal.lib;
23 
24 import com.sun.org.apache.xml.internal.dtm.ref.DTMNodeProxy;
25 
26 import org.w3c.dom.Node;
27 import org.w3c.dom.NodeList;
28 
29 /**
30  * The base class for some EXSLT extension classes.
31  * It contains common utility methods to be used by the sub-classes.
32  */
33 public abstract class ExsltBase
34 {
35   /**
36    * Return the string value of a Node
37    *
38    * @param n The Node.
39    * @return The string value of the Node
40    */
toString(Node n)41   protected static String toString(Node n)
42   {
43     if (n instanceof DTMNodeProxy)
44          return ((DTMNodeProxy)n).getStringValue();
45     else
46     {
47       String value = n.getNodeValue();
48       if (value == null)
49       {
50         NodeList nodelist = n.getChildNodes();
51         StringBuffer buf = new StringBuffer();
52         for (int i = 0; i < nodelist.getLength(); i++)
53         {
54           Node childNode = nodelist.item(i);
55           buf.append(toString(childNode));
56         }
57         return buf.toString();
58       }
59       else
60         return value;
61     }
62   }
63 
64   /**
65    * Convert the string value of a Node to a number.
66    * Return NaN if the string is not a valid number.
67    *
68    * @param n The Node.
69    * @return The number value of the Node
70    */
toNumber(Node n)71   protected static double toNumber(Node n)
72   {
73     double d = 0.0;
74     String str = toString(n);
75     try
76     {
77       d = Double.valueOf(str).doubleValue();
78     }
79     catch (NumberFormatException e)
80     {
81       d= Double.NaN;
82     }
83     return d;
84   }
85 }
86