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

   1 /* FunctionAvailableFunction.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.ArrayList;
  41 import java.util.Collection;
  42 import java.util.Collections;
  43 import java.util.Iterator;
  44 import java.util.List;
  45 import java.util.TreeSet;
  46 import javax.xml.namespace.NamespaceContext;
  47 import javax.xml.namespace.QName;
  48 import javax.xml.xpath.XPathFunction;
  49 import javax.xml.xpath.XPathFunctionException;
  50 import org.w3c.dom.Node;
  51 import gnu.xml.xpath.Expr;
  52 import gnu.xml.xpath.Function;
  53
  54 /**
  55  * The XSLT <code>function-available</code> function.
  56  *
  57  * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
  58  */
  59 class FunctionAvailableFunction
  60   extends Expr
  61   implements Function, XPathFunction
  62 {
  63
  64   static final Collection xsltFunctions;
  65   static final Collection xpathFunctions;
  66   static
  67   {
  68     TreeSet acc = new TreeSet();
  69     acc.add("document");
  70     acc.add("key");
  71     acc.add("format-number");
  72     acc.add("current");
  73     acc.add("unparsed-entity-uri");
  74     acc.add("generate-id");
  75     acc.add("system-property");
  76     acc.add("element-available");
  77     acc.add("function-available");
  78     xsltFunctions = Collections.unmodifiableSet(acc);
  79     acc = new TreeSet();
  80     acc.add("boolean");
  81     acc.add("ceiling");
  82     acc.add("concat");
  83     acc.add("contains");
  84     acc.add("count");
  85     acc.add("false");
  86     acc.add("floor");
  87     acc.add("id");
  88     acc.add("lang");
  89     acc.add("last");
  90     acc.add("local-name");
  91     acc.add("name");
  92     acc.add("namespace-uri");
  93     acc.add("normalize-space");
  94     acc.add("not");
  95     acc.add("number");
  96     acc.add("position");
  97     acc.add("round");
  98     acc.add("starts-with");
  99     acc.add("string");
 100     acc.add("string-length");
 101     acc.add("substring-after");
 102     acc.add("substring-before");
 103     acc.add("substring");
 104     acc.add("sum");
 105     acc.add("translate");
 106     acc.add("true");
 107     xpathFunctions = Collections.unmodifiableSet(acc);
 108   }
 109
 110   final NamespaceContext nsctx;
 111   List args;
 112
 113   FunctionAvailableFunction(NamespaceContext nsctx)
 114   {
 115     this.nsctx = nsctx;
 116   }
 117
 118   public Object evaluate(List args)
 119     throws XPathFunctionException
 120   {
 121     // Useless...
 122     return Collections.EMPTY_SET;
 123   }
 124
 125   public void setArguments(List args)
 126   {
 127     this.args = args;
 128   }
 129
 130   public Object evaluate(Node context, int pos, int len)
 131   {
 132     Expr arg = (Expr) args.get(0);
 133     Object val = arg.evaluate(context, pos, len);
 134     String name = _string(context, val);
 135     String prefix, localName, uri;
 136     int ci = name.indexOf(':');
 137     if (ci == -1)
 138       {
 139         prefix = null;
 140         localName = name;
 141       }
 142     else
 143       {
 144         prefix = name.substring(0, ci);
 145         localName = name.substring(ci + 1);
 146       }
 147     uri = nsctx.getNamespaceURI(prefix);
 148     if (uri == null)
 149       {
 150         return (xpathFunctions.contains(localName)  ||
 151                 xsltFunctions.contains(localName)) ?
 152           Boolean.TRUE : Boolean.FALSE;
 153       }
 154     else if (Stylesheet.XSL_NS.equals(uri))
 155       {
 156         return xsltFunctions.contains(localName) ?
 157           Boolean.TRUE : Boolean.FALSE;
 158       }
 159     // TODO extension functions
 160     return Boolean.FALSE;
 161   }
 162
 163   public Expr clone(Object context)
 164   {
 165     NamespaceContext n = nsctx;
 166     if (context instanceof NamespaceContext)
 167       n = (NamespaceContext) context;
 168     FunctionAvailableFunction f = new FunctionAvailableFunction(n);
 169     int len = args.size();
 170     List args2 = new ArrayList(len);
 171     for (int i = 0; i < len; i++)
 172       args2.add(((Expr) args.get(i)).clone(context));
 173     f.setArguments(args2);
 174     return f;
 175   }
 176
 177   public boolean references(QName var)
 178   {
 179     for (Iterator i = args.iterator(); i.hasNext(); )
 180       {
 181         if (((Expr) i.next()).references(var))
 182           return true;
 183       }
 184     return false;
 185   }
 186
 187   public String toString()
 188   {
 189     return "function-available(" + args.get(0) + ")";
 190   }
 191
 192 }
 193