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    1   /*
    2    * Licensed to the Apache Software Foundation (ASF) under one or more
    3    * contributor license agreements.  See the NOTICE file distributed with
    4    * this work for additional information regarding copyright ownership.
    5    * The ASF licenses this file to You under the Apache License, Version 2.0
    6    * (the "License"); you may not use this file except in compliance with
    7    * the License.  You may obtain a copy of the License at
    8    *
    9    *  http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   */
    17
    18  package org.apache.any23.extractor.html.microformats2;
    19
    20  import org.apache.any23.extractor.ExtractionException;
    21  import org.apache.any23.extractor.ExtractionResult;
    22  import org.apache.any23.extractor.ExtractorDescription;
    23  import org.apache.any23.extractor.TagSoupExtractionResult;
    24  import org.apache.any23.vocab.HItem;
    25  import org.eclipse.rdf4j.model.BNode;
    26  import org.eclipse.rdf4j.model.IRI;
    27  import org.eclipse.rdf4j.model.vocabulary.RDF;
    28  import org.w3c.dom.Node;
    29  import org.apache.any23.extractor.html.EntityBasedMicroformatExtractor;
    30  import org.apache.any23.extractor.html.HTMLDocument;
    31
    32  /**
    33   * Extractor for the <a href="http://microformats.org/wiki/h-item">h-item</a> microformat.
    34   *
    35   * @author Nisala Nirmana
    36   */
    37  public class HItemExtractor extends EntityBasedMicroformatExtractor {
    38
    39      private static final HItem vHITEM = HItem.getInstance();
    40
    41      private static final String[] itemFields = { "name", "url", "photo" };
    42
    43      @Override
    44      public ExtractorDescription getDescription() {
    45          return HItemExtractorFactory.getDescriptionInstance();
    46      }
    47
    48      protected String getBaseClassName() {
    49          return Microformats2Prefixes.CLASS_PREFIX + "item";
    50      }
    51
    52      @Override
    53      protected void resetExtractor() {
    54          // Empty.
    55      }
    56
    57      protected boolean extractEntity(Node node, ExtractionResult out) throws ExtractionException {
    58          if (null == node)
    59              return false;
    60          final HTMLDocument document = new HTMLDocument(node);
    61          BNode item = getBlankNodeFor(node);
    62          out.writeTriple(item, RDF.TYPE, vHITEM.Item);
    63          final String extractorName = getDescription().getExtractorName();
    64          addName(document, item);
    65          addPhotos(document, item);
    66          addUrls(document, item);
    67          final TagSoupExtractionResult tser = (TagSoupExtractionResult) getCurrentExtractionResult();
    68          tser.addResourceRoot(document.getPathToLocalRoot(), item, this.getClass());
    69          return true;
    70      }
    71
    72      private void mapFieldWithProperty(HTMLDocument fragment, BNode item, String fieldClass, IRI property) {
    73          HTMLDocument.TextField title = fragment.getSingularTextField(fieldClass);
    74          conditionallyAddStringProperty(title.source(), item, property, title.value());
    75      }
    76
    77      private void addName(HTMLDocument fragment, BNode item) {
    78          mapFieldWithProperty(fragment, item, Microformats2Prefixes.PROPERTY_PREFIX + itemFields[0], vHITEM.name);
    79      }
    80
    81      private void addPhotos(HTMLDocument fragment, BNode item) throws ExtractionException {
    82          final HTMLDocument.TextField[] photos = fragment
    83                  .getPluralUrlField(Microformats2Prefixes.URL_PROPERTY_PREFIX + itemFields[2]);
    84          for (HTMLDocument.TextField photo : photos) {
    85              addIRIProperty(item, vHITEM.photo, fragment.resolveIRI(photo.value()));
    86          }
    87      }
    88
    89      private void addUrls(HTMLDocument fragment, BNode item) throws ExtractionException {
    90          HTMLDocument.TextField[] links = fragment
    91                  .getPluralUrlField(Microformats2Prefixes.URL_PROPERTY_PREFIX + itemFields[1]);
    92          for (HTMLDocument.TextField link : links) {
    93              conditionallyAddResourceProperty(item, vHITEM.url, getHTMLDocument().resolveIRI(link.value()));
    94          }
    95      }
    96  }