/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-2015 The eXist Project
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.exist.xquery.modules.ngram;
import java.io.IOException;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import org.exist.dom.persistent.Match;
import org.exist.dom.persistent.NodeProxy;
import org.exist.dom.QName;
import org.exist.indexing.ngram.NGramMatch;
import org.exist.numbering.NodeId;
import org.exist.stax.ExtendedXMLStreamReader;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.NodeValue;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
import org.exist.xquery.ErrorCodes;
public class AddMatch extends BasicFunction {
public final static FunctionSignature signature = new FunctionSignature(
new QName("add-match", NGramModule.NAMESPACE_URI, NGramModule.PREFIX),
"For each of the nodes in the argument sequence, mark the entire first text descendant as a " +
"text match, just as if it had been found through a search operation. At serialization time, " +
"the text node will be enclosed in an <exist:match> tag, which facilitates further processing " +
"by the kwic module or match highlighting. The function is not directly related to the NGram index" +
"and works without an index; " +
"it just uses the NGram module's match processor.",
new SequenceType[]{
new FunctionParameterSequenceType("node-set", Type.NODE, Cardinality.ZERO_OR_ONE, "The node set")
},
new FunctionReturnSequenceType(Type.NODE, Cardinality.ZERO_OR_MORE, "a node set containing nodes that do not have descendent nodes."));
public AddMatch(XQueryContext context) {
super(context, signature);
}
@Override
public Sequence eval(Sequence[] args, Sequence contextSequence)
throws XPathException {
if (args[0].isEmpty())
return args[0];
NodeValue nv = (NodeValue) args[0].itemAt(0);
if (!nv.isPersistentSet())
return nv;
NodeProxy node = (NodeProxy) nv;
String matchStr = null;
NodeId nodeId = null;
try {
for (final XMLStreamReader reader = context.getBroker().getXMLStreamReader(node, true); reader.hasNext(); ) {
int status = reader.next();
if (status == XMLStreamConstants.CHARACTERS) {
matchStr = reader.getText();
nodeId = (NodeId) reader.getProperty(ExtendedXMLStreamReader.PROPERTY_NODE_ID);
break;
}
}
} catch (IOException e) {
throw new XPathException(this, ErrorCodes.FOER0000, "Exception caught while reading document");
} catch (XMLStreamException e) {
throw new XPathException(this, ErrorCodes.FOER0000, "Exception caught while reading document");
}
if (nodeId != null) {
Match match = new NGramMatch(getContextId(), node.getNodeId(), matchStr);
match.addOffset(0, matchStr.length());
node.addMatch(match);
}
return node;
}
}