001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements. See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership. The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the  "License");
007     * you may not use this file except in compliance with the License.
008     * You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    /*
019     * $Id: KeyRefIterator.java 468645 2006-10-28 06:57:24Z minchau $
020     */
021    package org.apache.xalan.transformer;
022    
023    import java.util.Vector;
024    
025    import org.apache.xalan.res.XSLMessages;
026    import org.apache.xalan.res.XSLTErrorResources;
027    import org.apache.xalan.templates.KeyDeclaration;
028    import org.apache.xml.dtm.DTM;
029    import org.apache.xml.dtm.DTMIterator;
030    import org.apache.xml.utils.QName;
031    import org.apache.xml.utils.XMLString;
032    import org.apache.xpath.objects.XNodeSet;
033    import org.apache.xpath.objects.XObject;
034    
035    /**
036     * This class filters nodes from a key iterator, according to 
037     * whether or not the use value matches the ref value.  
038     * @xsl.usage internal
039     */
040    public class KeyRefIterator extends org.apache.xpath.axes.ChildTestIterator
041    {
042        static final long serialVersionUID = 3837456451659435102L;
043      /**
044       * Constructor KeyRefIterator
045       *
046       *
047       * @param ref Key value to match
048       * @param ki The main key iterator used to walk the source tree 
049       */
050      public KeyRefIterator(QName name, XMLString ref, Vector keyDecls, DTMIterator ki)
051      {
052        super(null);
053        m_name = name;
054        m_ref = ref;
055        m_keyDeclarations = keyDecls;
056        m_keysNodes = ki;
057        setWhatToShow(org.apache.xml.dtm.DTMFilter.SHOW_ALL);
058      }
059      
060      DTMIterator m_keysNodes;
061      
062      /**
063       * Get the next node via getNextXXX.  Bottlenecked for derived class override.
064       * @return The next node on the axis, or DTM.NULL.
065       */
066      protected int getNextNode()
067      {                  
068            int next;   
069        while(DTM.NULL != (next = m_keysNodes.nextNode()))
070        {
071            if(DTMIterator.FILTER_ACCEPT == filterNode(next))
072                    break;
073        }
074        m_lastFetched = next;
075        
076        return next;
077      }
078    
079    
080      /**
081       *  Test whether a specified node is visible in the logical view of a
082       * TreeWalker or NodeIterator. This function will be called by the
083       * implementation of TreeWalker and NodeIterator; it is not intended to
084       * be called directly from user code.
085       * 
086       * @param testNode  The node to check to see if it passes the filter or not.
087       *
088       * @return  a constant to determine whether the node is accepted,
089       *   rejected, or skipped, as defined  above .
090       */
091      public short filterNode(int testNode)
092      {
093        boolean foundKey = false;
094        Vector keys = m_keyDeclarations;
095    
096        QName name = m_name;
097        KeyIterator ki = (KeyIterator)(((XNodeSet)m_keysNodes).getContainedIter());
098        org.apache.xpath.XPathContext xctxt = ki.getXPathContext();
099        
100        if(null == xctxt)
101            assertion(false, "xctxt can not be null here!");
102    
103        try
104        {
105          XMLString lookupKey = m_ref;
106    
107          // System.out.println("lookupKey: "+lookupKey);
108          int nDeclarations = keys.size();
109    
110          // Walk through each of the declarations made with xsl:key
111          for (int i = 0; i < nDeclarations; i++)
112          {
113            KeyDeclaration kd = (KeyDeclaration) keys.elementAt(i);
114    
115            // Only continue if the name on this key declaration
116            // matches the name on the iterator for this walker. 
117            if (!kd.getName().equals(name))
118              continue;
119    
120            foundKey = true;
121            // xctxt.setNamespaceContext(ki.getPrefixResolver());
122    
123            // Query from the node, according the the select pattern in the
124            // use attribute in xsl:key.
125            XObject xuse = kd.getUse().execute(xctxt, testNode, ki.getPrefixResolver());
126    
127            if (xuse.getType() != xuse.CLASS_NODESET)
128            {
129              XMLString exprResult = xuse.xstr();
130    
131              if (lookupKey.equals(exprResult))
132                return DTMIterator.FILTER_ACCEPT;
133            }
134            else
135            {
136              DTMIterator nl = ((XNodeSet)xuse).iterRaw();
137              int useNode;
138              
139              while (DTM.NULL != (useNode = nl.nextNode()))
140              {
141                DTM dtm = getDTM(useNode);
142                XMLString exprResult = dtm.getStringValue(useNode);
143                if ((null != exprResult) && lookupKey.equals(exprResult))
144                  return DTMIterator.FILTER_ACCEPT;
145              }
146            }
147    
148          } // end for(int i = 0; i < nDeclarations; i++)
149        }
150        catch (javax.xml.transform.TransformerException te)
151        {
152          throw new org.apache.xml.utils.WrappedRuntimeException(te);
153        }
154    
155        if (!foundKey)
156          throw new RuntimeException(
157            XSLMessages.createMessage(
158              XSLTErrorResources.ER_NO_XSLKEY_DECLARATION,
159              new Object[] { name.getLocalName()}));
160        return DTMIterator.FILTER_REJECT;
161      }
162    
163      protected XMLString m_ref;
164      protected QName m_name;
165    
166      /** Vector of Key declarations in the stylesheet.
167       *  @serial          */
168      protected Vector m_keyDeclarations;
169    
170    }