restconf/restconf-nb/src/main/java/org/opendaylight/restconf/nb/rfc8040/streams/listeners/XMLDataTreeCandidateFormatter.java

   1 /*
   2  * Copyright (c) 2020 PANTHEON.tech, s.r.o. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.restconf.nb.rfc8040.streams.listeners;
   9
  10 import static org.opendaylight.restconf.nb.rfc8040.streams.listeners.NotificationFormatter.DATA_CHANGED_NOTIFICATION_ELEMENT;
  11 import static org.opendaylight.restconf.nb.rfc8040.streams.listeners.NotificationFormatter.SAL_REMOTE_NAMESPACE;
  12
  13 import java.io.IOException;
  14 import java.io.StringWriter;
  15 import java.time.Instant;
  16 import java.util.Collection;
  17 import javax.xml.stream.XMLStreamException;
  18 import javax.xml.xpath.XPathExpressionException;
  19 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeCandidate;
  20 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  21
  22 public final class XMLDataTreeCandidateFormatter extends DataTreeCandidateFormatter {
  23     private static final XMLDataTreeCandidateFormatter INSTANCE = new XMLDataTreeCandidateFormatter();
  24
  25     static final DataTreeCandidateFormatterFactory FACTORY =
  26         new DataTreeCandidateFormatterFactory() {
  27             @Override
  28             public XMLDataTreeCandidateFormatter getFormatter(final String xpathFilter)
  29                     throws XPathExpressionException {
  30                 return new XMLDataTreeCandidateFormatter(xpathFilter);
  31             }
  32
  33             @Override
  34             public XMLDataTreeCandidateFormatter getFormatter() {
  35                 return INSTANCE;
  36             }
  37         };
  38
  39     private XMLDataTreeCandidateFormatter() {
  40
  41     }
  42
  43     private XMLDataTreeCandidateFormatter(final String xpathFilter) throws XPathExpressionException {
  44         super(xpathFilter);
  45     }
  46
  47     @Override
  48     String createText(final EffectiveModelContext schemaContext, final Collection<DataTreeCandidate> input,
  49             final Instant now, final boolean leafNodesOnly, final boolean skipData, final boolean changedLeafNodesOnly,
  50             final boolean childNodeOnly) throws Exception {
  51         final var writer = new StringWriter();
  52         boolean nonEmpty = false;
  53         try {
  54             final var xmlStreamWriter = NotificationFormatter.createStreamWriterWithNotification(writer, now);
  55
  56             xmlStreamWriter.setDefaultNamespace(SAL_REMOTE_NAMESPACE);
  57             xmlStreamWriter.writeStartElement(SAL_REMOTE_NAMESPACE, DATA_CHANGED_NOTIFICATION_ELEMENT);
  58
  59             final var serializer = new XmlDataTreeCandidateSerializer(schemaContext, xmlStreamWriter);
  60             for (var candidate : input) {
  61                 nonEmpty |= serializer.serialize(candidate, leafNodesOnly, skipData, changedLeafNodesOnly,
  62                     childNodeOnly);
  63             }
  64
  65             // data-changed-notification
  66             xmlStreamWriter.writeEndElement();
  67
  68             // notification
  69             xmlStreamWriter.writeEndElement();
  70             xmlStreamWriter.close();
  71         } catch (XMLStreamException e) {
  72             throw new IOException("Failed to write notification content", e);
  73         }
  74
  75         return nonEmpty ? writer.toString() : null;
  76     }
  77 }