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