Source for gnu.xml.xpath.VariableReference

   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: 
  54:   public VariableReference(XPathVariableResolver resolver, QName name)
  55:   {
  56:     this.resolver = resolver;
  57:     this.name = name;
  58:   }
  59: 
  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: 
  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: 
  84:   public boolean references(QName var)
  85:   {
  86:     return name.equals(var);
  87:   }
  88: 
  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: }