gomp-20050608-branch/libjava/classpath/gnu/xml/transform/ParameterNode.java

   1 /* ParameterNode.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.transform;
  39
  40 import java.util.Collections;
  41 import javax.xml.namespace.QName;
  42 import javax.xml.transform.TransformerException;
  43 import org.w3c.dom.Document;
  44 import org.w3c.dom.DocumentFragment;
  45 import org.w3c.dom.Node;
  46 import gnu.xml.xpath.Expr;
  47
  48 /**
  49  * A template node that sets a variable or parameter during template
  50  * processing.
  51  *
  52  * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
  53  */
  54 final class ParameterNode
  55   extends TemplateNode
  56   implements Comparable
  57 {
  58
  59   final QName name;
  60   final Expr select;
  61   final int type;
  62
  63   ParameterNode(QName name, Expr select, int type)
  64   {
  65     this.name = name;
  66     this.select = select;
  67     this.type = type;
  68   }
  69
  70   TemplateNode clone(Stylesheet stylesheet)
  71   {
  72     TemplateNode ret = new ParameterNode(name,
  73                                          select.clone(stylesheet),
  74                                          type);
  75     if (children != null)
  76       {
  77         ret.children = children.clone(stylesheet);
  78       }
  79     if (next != null)
  80       {
  81         ret.next = next.clone(stylesheet);
  82       }
  83     return ret;
  84   }
  85
  86   void doApply(Stylesheet stylesheet, QName mode,
  87                Node context, int pos, int len,
  88                Node parent, Node nextSibling)
  89     throws TransformerException
  90   {
  91     // push the variable context
  92     stylesheet.bindings.push(type);
  93     // set the variable
  94     Object value = getValue(stylesheet, mode, context, pos, len);
  95     if (value != null)
  96       {
  97         stylesheet.bindings.set(name, value, type);
  98         if (stylesheet.debug)
  99           {
 100             System.err.println(this + ": set to " + value);
 101           }
 102       }
 103     // variable and param don't process children as such
 104     // all subsequent instructions are processed with that variable context
 105     if (next != null)
 106       {
 107         next.apply(stylesheet, mode,
 108                    context, pos, len,
 109                    parent, nextSibling);
 110       }
 111     // pop the variable context
 112     stylesheet.bindings.pop(type);
 113   }
 114
 115   Object getValue(Stylesheet stylesheet, QName mode,
 116                   Node context, int pos, int len)
 117     throws TransformerException
 118   {
 119     if (select != null)
 120       {
 121         return select.evaluate(context, pos, len);
 122       }
 123     else if (children != null)
 124       {
 125         Document doc = (context instanceof Document) ? (Document) context :
 126           context.getOwnerDocument();
 127         DocumentFragment fragment = doc.createDocumentFragment();
 128         children.apply(stylesheet, mode, context, pos, len, fragment, null);
 129         return Collections.singleton(fragment);
 130       }
 131     else
 132       {
 133         return null;
 134       }
 135   }
 136
 137   public boolean references(QName var)
 138   {
 139     if (select != null && select.references(var))
 140       {
 141         return true;
 142       }
 143     return super.references(var);
 144   }
 145
 146   public int compareTo(Object other)
 147   {
 148     if (other instanceof ParameterNode)
 149       {
 150         ParameterNode pn = (ParameterNode) other;
 151         boolean r1 = references(pn.name);
 152         boolean r2 = pn.references(name);
 153         if (r1 && r2)
 154           {
 155             throw new IllegalArgumentException("circular definitions");
 156           }
 157         if (r1)
 158           {
 159             return 1;
 160           }
 161         if (r2)
 162           {
 163             return -1;
 164           }
 165       }
 166     return 0;
 167   }
 168
 169   public String toString()
 170   {
 171     StringBuffer buf = new StringBuffer(getClass().getName());
 172     buf.append('[');
 173     buf.append("name=");
 174     buf.append(name);
 175     if (select != null)
 176       {
 177         buf.append(",select=");
 178         buf.append(select);
 179       }
 180     buf.append(",type=");
 181     switch (type)
 182       {
 183       case Bindings.VARIABLE:
 184         buf.append("variable");
 185         break;
 186       case Bindings.PARAM:
 187         buf.append("param");
 188         break;
 189       case Bindings.WITH_PARAM:
 190         buf.append("with-param");
 191         break;
 192       }
 193     buf.append(']');
 194     return buf.toString();
 195   }
 196
 197 }
 198