1 /* VariableReference.java --
2    Copyright (C) 2004 Free Software Foundation, Inc.
3 
4 This file is part of GNU Classpath.
5 
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10 
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 General Public License for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING.  If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 02110-1301 USA.
20 
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library.  Thus, the terms and
23 conditions of the GNU General Public License cover the whole
24 combination.
25 
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module.  An independent module is a module which is not derived from
33 or based on this library.  If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so.  If you do not wish to do so, delete this
36 exception statement from your version. */
37 
38 package gnu.xml.xpath;
39 
40 import gnu.java.lang.CPStringBuilder;
41 
42 import javax.xml.namespace.QName;
43 import javax.xml.xpath.XPathVariableResolver;
44 import org.w3c.dom.Node;
45 import gnu.xml.transform.Bindings;
46 
47 public class VariableReference
48   extends Expr
49 {
50 
51   final XPathVariableResolver resolver;
52   final QName name;
53 
VariableReference(XPathVariableResolver resolver, QName name)54   public VariableReference(XPathVariableResolver resolver, QName name)
55   {
56     this.resolver = resolver;
57     this.name = name;
58   }
59 
evaluate(Node context, int pos, int len)60   public Object evaluate(Node context, int pos, int len)
61   {
62     if (resolver != null)
63       {
64         if (resolver instanceof Bindings)
65           {
66             // Needs context to operate properly
67             return ((Bindings) resolver).get(name, context, pos, len);
68           }
69         return resolver.resolveVariable(name);
70       }
71     throw new IllegalStateException("no variable resolver");
72   }
73 
clone(Object context)74   public Expr clone(Object context)
75   {
76     XPathVariableResolver r = resolver;
77     if (context instanceof XPathVariableResolver)
78       {
79         r = (XPathVariableResolver) context;
80       }
81     return new VariableReference(r, name);
82   }
83 
references(QName var)84   public boolean references(QName var)
85   {
86     return name.equals(var);
87   }
88 
toString()89   public String toString()
90   {
91     CPStringBuilder buf = new CPStringBuilder("$");
92     String prefix = name.getPrefix();
93     if (prefix != null && !"".equals(prefix))
94       {
95         buf.append(prefix);
96         buf.append(':');
97       }
98     buf.append(name.getLocalPart());
99     return buf.toString();
100   }
101 
102 }
103