libjava/classpath/gnu/xml/transform/ParameterNode.java

   1 /* ParameterNode.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.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       ret.children = children.clone(stylesheet);
  77     if (next != null)
  78       ret.next = next.clone(stylesheet);
  79     return ret;
  80   }
  81
  82   void doApply(Stylesheet stylesheet, QName mode,
  83                Node context, int pos, int len,
  84                Node parent, Node nextSibling)
  85     throws TransformerException
  86   {
  87     // push the variable context
  88     stylesheet.bindings.push(type);
  89     // set the variable
  90     Object value = getValue(stylesheet, mode, context, pos, len);
  91     if (value != null)
  92       {
  93         stylesheet.bindings.set(name, value, type);
  94         if (stylesheet.debug)
  95           System.err.println(this + ": set to " + value);
  96       }
  97     // variable and param don't process children as such
  98     // all subsequent instructions are processed with that variable context
  99     if (next != null)
 100       next.apply(stylesheet, mode,
 101                  context, pos, len,
 102                  parent, nextSibling);
 103     // pop the variable context
 104     stylesheet.bindings.pop(type);
 105   }
 106
 107   Object getValue(Stylesheet stylesheet, QName mode,
 108                   Node context, int pos, int len)
 109     throws TransformerException
 110   {
 111     if (select != null)
 112       return select.evaluate(context, pos, len);
 113     else if (children != null)
 114       {
 115         Document doc = (context instanceof Document) ? (Document) context :
 116           context.getOwnerDocument();
 117         DocumentFragment fragment = doc.createDocumentFragment();
 118         children.apply(stylesheet, mode, context, pos, len, fragment, null);
 119         return Collections.singleton(fragment);
 120       }
 121     else
 122       return null;
 123   }
 124
 125   public boolean references(QName var)
 126   {
 127     if (select != null && select.references(var))
 128       return true;
 129     return super.references(var);
 130   }
 131
 132   public int compareTo(Object other)
 133   {
 134     if (other instanceof ParameterNode)
 135       {
 136         ParameterNode pn = (ParameterNode) other;
 137         boolean r1 = references(pn.name);
 138         boolean r2 = pn.references(name);
 139         if (r1 && r2)
 140           throw new IllegalArgumentException("circular definitions");
 141         if (r1)
 142           return 1;
 143         if (r2)
 144           return -1;
 145       }
 146     return 0;
 147   }
 148
 149   public String toString()
 150   {
 151     StringBuffer buf = new StringBuffer();
 152     switch (type)
 153       {
 154       case Bindings.VARIABLE:
 155         buf.append("variable");
 156         break;
 157       case Bindings.PARAM:
 158         buf.append("param");
 159         break;
 160       case Bindings.WITH_PARAM:
 161         buf.append("with-param");
 162         break;
 163       }
 164     buf.append('[');
 165     buf.append("name=");
 166     buf.append(name);
 167     if (select != null)
 168       {
 169         buf.append(",select=");
 170         buf.append(select);
 171       }
 172     buf.append(']');
 173     return buf.toString();
 174   }
 175
 176 }
 177