Initial revision

From-SVN: r102074

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

@@ -0,0 +1,228 @@
+/* KeyFunction.java -- 
+   Copyright (C) 2004 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package gnu.xml.transform;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
+import java.util.LinkedList;
+import java.util.List;
+import javax.xml.namespace.QName;
+import javax.xml.xpath.XPathFunction;
+import javax.xml.xpath.XPathFunctionException;
+import org.w3c.dom.Document;
+import org.w3c.dom.Node;
+import gnu.xml.xpath.Expr;
+import gnu.xml.xpath.Function;
+import gnu.xml.xpath.Pattern;
+
+/**
+ * The XSLT <code>key()</code>function.
+ *
+ * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
+ */
+final class KeyFunction
+  extends Pattern
+  implements XPathFunction, Function
+{
+
+  final Stylesheet stylesheet;
+  List args;
+
+  KeyFunction(Stylesheet stylesheet)
+  {
+    this.stylesheet = stylesheet;
+  }
+
+  public Object evaluate(List args)
+    throws XPathFunctionException
+  {
+    // Useless...
+    return Collections.EMPTY_SET;
+  }
+
+  public void setArguments(List args)
+  {
+    this.args = args;
+  }
+
+  public boolean matches(Node context)
+  {
+    Object ret = evaluate(context, 1, 1);
+    return !((Collection) ret).isEmpty();
+  }
+
+  public Object evaluate(Node context, int pos, int len)
+  {
+    // Evaluate arguments
+    int arity = args.size();
+    List values = new ArrayList(arity);
+    for (int i = 0; i < arity; i++)
+      {
+        Expr arg = (Expr) args.get(i);
+        values.add(arg.evaluate(context, pos, len));
+      }
+    // Get key name
+    QName keyName = QName.valueOf(_string(context, values.get(0)));
+    // Expand qualified name
+    String uri = keyName.getNamespaceURI();
+    String prefix = keyName.getPrefix();
+    if ((uri == null || uri.length() == 0) && 
+        (prefix != null && prefix.length() > 0))
+      {
+        uri = stylesheet.getNamespaceURI(prefix);
+        if (uri != null && uri.length() > 0)
+          {
+            String localName = keyName.getLocalPart();
+            keyName = new QName(uri, localName, prefix);
+          }
+      }
+    // Compute matching key set
+    Collection keySet = new LinkedList();
+    for (Iterator i = stylesheet.keys.iterator(); i.hasNext(); )
+      {
+        Key key = (Key) i.next();
+        if (key.name.equals(keyName))
+          {
+            keySet.add(key);
+          }
+      }
+    // Get target
+    Object target = values.get(1);
+    Collection acc = new LinkedHashSet();
+    Document doc = (context instanceof Document) ? (Document) context :
+      context.getOwnerDocument();
+    if (target instanceof Collection)
+      {
+        for (Iterator i = ((Collection) target).iterator(); i.hasNext(); )
+          {
+            String val = Expr.stringValue((Node) i.next());
+            addKeyNodes(doc, keySet, val, acc);
+          }
+      }
+    else
+      {
+        String val = Expr._string(context, target);
+        addKeyNodes(doc, keySet, val, acc);
+      }
+    List ret = new ArrayList(acc);
+    Collections.sort(ret, documentOrderComparator);
+    return ret;
+  }
+
+  final void addKeyNodes(Node node, Collection keySet,
+                         String value, Collection acc)
+  {
+    addKeyNodeIfMatch(node, keySet, value, acc);
+    // Apply children
+    for (Node ctx = node.getFirstChild(); ctx != null;
+         ctx = ctx.getNextSibling())
+      {
+        addKeyNodes(ctx, keySet, value, acc);
+      }
+  }
+  
+  final void addKeyNodeIfMatch(Node node, Collection keySet,
+                               String value, Collection acc)
+  {
+    for (Iterator i = keySet.iterator(); i.hasNext(); )
+      {
+        Key key = (Key) i.next();
+        if (key.match.matches(node))
+          {
+            Object eval = key.use.evaluate(node, 1, 1);
+            if (eval instanceof Collection)
+              {
+                for (Iterator j = ((Collection) eval).iterator();
+                     j.hasNext(); )
+                  {
+                    String keyValue = Expr.stringValue((Node) j.next());
+                    if (value.equals(keyValue))
+                      {
+                        acc.add(node);
+                        return;
+                      }
+                  }
+              }
+            else
+              {
+                String keyValue = Expr._string(node, eval);
+                if (value.equals(keyValue))
+                  {
+                    acc.add(node);
+                    return;
+                  }
+              }
+          }
+      }
+  }
+
+  public Expr clone(Object context)
+  {
+    Stylesheet s = stylesheet;
+    if (context instanceof Stylesheet)
+      {
+        s = (Stylesheet) context;
+      }
+    KeyFunction f = new KeyFunction(s);
+    int len = args.size();
+    List args2 = new ArrayList(len);
+    for (int i = 0; i < len; i++)
+      {
+        args2.add(((Expr) args.get(i)).clone(context));
+      }
+    f.setArguments(args2);
+    return f;
+  }
+
+  public boolean references(QName var)
+  {
+    for (Iterator i = args.iterator(); i.hasNext(); )
+      {
+        if (((Expr) i.next()).references(var))
+          {
+            return true;
+          }
+      }
+    return false;
+  }
+
+}
+