libjava/classpath/gnu/xml/xpath/NameFunction.java

   1 /* NameFunction.java --
   2    Copyright (C) 2004,2006 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 java.util.Collection;
  41 import java.util.Collections;
  42 import java.util.List;
  43 import javax.xml.namespace.QName;
  44 import org.w3c.dom.Node;
  45
  46 /**
  47  * The <code>name</code> function returns a string containing a QName
  48  * representing the expanded-name of the node in the argument node-set that
  49  * is first in document order. The QName must represent the expanded-name
  50  * with respect to the namespace declarations in effect on the node whose
  51  * expanded-name is being represented. Typically, this will be the QName
  52  * that occurred in the XML source. This need not be the case if there are
  53  * namespace declarations in effect on the node that associate multiple
  54  * prefixes with the same namespace. However, an implementation may include
  55  * information about the original prefix in its representation of nodes; in
  56  * this case, an implementation can ensure that the returned string is
  57  * always the same as the QName used in the XML source. If the argument
  58  * node-set is empty or the first node has no expanded-name, an empty string
  59  * is returned. If the argument it omitted, it defaults to a node-set with
  60  * the context node as its only member.
  61  *
  62  * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
  63  */
  64 final class NameFunction
  65   extends Expr
  66 {
  67
  68   final Expr arg;
  69
  70   NameFunction(List args)
  71   {
  72     this(args.size() > 0 ? (Expr) args.get(0) : null);
  73   }
  74
  75   NameFunction(Expr arg)
  76   {
  77     this.arg = arg;
  78   }
  79
  80   public Object evaluate(Node context, int pos, int len)
  81   {
  82     Object val = (arg == null) ? Collections.singleton(context) :
  83         arg.evaluate(context, pos, len);
  84     return _name(context, (Collection) val);
  85   }
  86
  87   public Expr clone(Object context)
  88   {
  89     return new NameFunction((arg == null) ? null :
  90                             arg.clone(context));
  91   }
  92
  93   public boolean references(QName var)
  94   {
  95     return (arg == null) ? false : arg.references(var);
  96   }
  97
  98   public String toString()
  99   {
 100     return (arg == null) ? "name()" : "name(" + arg + ")";
 101   }
 102
 103 }