libjava/gnu/xml/transform/Bindings.java

   1 /* Bindings.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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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.Collection;
  41 import java.util.Collections;
  42 import java.util.HashMap;
  43 import java.util.HashSet;
  44 import java.util.Iterator;
  45 import java.util.LinkedList;
  46 import java.util.Map;
  47 import javax.xml.namespace.QName;
  48 import javax.xml.xpath.XPathVariableResolver;
  49 import org.w3c.dom.Node;
  50
  51 /**
  52  * The set of variable bindings in effect for a stylesheet.
  53  *
  54  * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
  55  */
  56 public class Bindings
  57   implements XPathVariableResolver, Cloneable
  58 {
  59
  60   final Stylesheet stylesheet;
  61
  62   /**
  63    * Global variables.
  64    */
  65   final LinkedList variables;
  66
  67   /**
  68    * Parameter value stack.
  69    */
  70   final LinkedList parameters;
  71
  72   Bindings(Stylesheet stylesheet)
  73   {
  74     this.stylesheet = stylesheet;
  75     variables = new LinkedList();
  76     parameters = new LinkedList();
  77     push(true);
  78     push(false);
  79   }
  80
  81   public Object clone()
  82   {
  83     try
  84       {
  85         return (Bindings) super.clone();
  86       }
  87     catch (CloneNotSupportedException e)
  88       {
  89         throw new Error(e.getMessage());
  90       }
  91   }
  92
  93   void push(boolean global)
  94   {
  95     if (global)
  96       {
  97         variables.addFirst(new HashMap());
  98       }
  99     else
 100       {
 101         parameters.addFirst(new HashMap());
 102       }
 103   }
 104
 105   void pop(boolean global)
 106   {
 107     if (global)
 108       {
 109         variables.removeFirst();
 110       }
 111     else
 112       {
 113         parameters.removeFirst();
 114       }
 115   }
 116
 117   public boolean containsKey(String name, boolean global)
 118   {
 119     Iterator i = global ? variables.iterator() : parameters.iterator();
 120     while (i.hasNext())
 121       {
 122         Map ctx = (Map) i.next();
 123         if (ctx.containsKey(name))
 124           {
 125             return true;
 126           }
 127       }
 128     return false;
 129   }
 130
 131   public Object get(String name, Node context, int pos, int len)
 132   {
 133     //System.err.println("bindings.get: "+name);
 134     //System.err.println("\t"+toString());
 135     Object ret = null;
 136     for (Iterator i = variables.iterator(); i.hasNext() && ret == null; )
 137       {
 138         Map vctx = (Map) i.next();
 139         ret = vctx.get(name);
 140       }
 141     if (ret == null)
 142       {
 143         for (Iterator i = parameters.iterator(); i.hasNext() && ret == null; )
 144           {
 145             Map pctx = (Map) i.next();
 146             ret = pctx.get(name);
 147           }
 148       }
 149     /*if (ret instanceof Expr && context != null)
 150       {
 151         Expr expr = (Expr) ret;
 152         ret = expr.evaluate(context, 1, 1);
 153       }*/
 154     if (ret instanceof Node)
 155       {
 156         ret = Collections.singleton(ret);
 157       }
 158     if (ret == null)
 159       {
 160         ret = "";
 161       }
 162     //System.err.println("\tret="+ret);
 163     return ret;
 164   }
 165
 166   void set(String name, Object value, boolean global)
 167   {
 168     if (global)
 169       {
 170         Map context = (Map) variables.getFirst();
 171         context.put(name, value);
 172       }
 173     else
 174       {
 175         Map context = (Map) parameters.getFirst();
 176         context.put(name, value);
 177       }
 178   }
 179
 180   public Object resolveVariable(QName qName)
 181   {
 182     return get(qName.toString(), null, 1, 1);
 183   }
 184
 185   public String toString()
 186   {
 187     StringBuffer buf = new StringBuffer();
 188     boolean next = false;
 189     Collection seen = new HashSet();
 190     buf.append('{');
 191     for (Iterator i = variables.iterator(); i.hasNext(); )
 192       {
 193         Map ctx = (Map) i.next();
 194         for (Iterator j = ctx.entrySet().iterator(); j.hasNext(); )
 195           {
 196             if (next)
 197               {
 198                 buf.append(',');
 199               }
 200             else
 201               {
 202                 next = true;
 203               }
 204             Map.Entry entry = (Map.Entry) j.next();
 205             Object key = entry.getKey();
 206             if (!seen.contains(key))
 207               {
 208                 buf.append(key);
 209                 buf.append('=');
 210                 buf.append(entry.getValue());
 211                 seen.add(key);
 212               }
 213           }
 214       }
 215     for (Iterator i = parameters.iterator(); i.hasNext(); )
 216       {
 217         Map ctx = (Map) i.next();
 218         for (Iterator j = ctx.entrySet().iterator(); j.hasNext(); )
 219           {
 220             if (next)
 221               {
 222                 buf.append(',');
 223               }
 224             else
 225               {
 226                 next = true;
 227               }
 228             Map.Entry entry = (Map.Entry) j.next();
 229             Object key = entry.getKey();
 230             if (!seen.contains(key))
 231               {
 232                 buf.append(key);
 233                 buf.append('=');
 234                 buf.append(entry.getValue());
 235                 seen.add(key);
 236               }
 237           }
 238       }
 239     buf.append('}');
 240     return buf.toString();
 241   }
 242 }