Indexing image alt text in HTML documents

The default parsing rules do not index the content of alt attributes in HTML elements, such as <img alt="content"/>. To ensure that the alt text is indexed, you must specify rules in a parser configuration file.

To configure the parser to add content from alt text to the index:

1. Log in as the default Watson Content Analytics administrator on the master server and edit the ES_NODE_ROOT/master_config/collection_ID.indexservice/parser_config.xml file, where collection_ID identifies the collection that you want to customize.
2. Add the following rule to the file and save your changes:

   <Rule>
     <Conditions>
      <Element Name="img" />
     </Conditions>
     <Actions>
      <AttributeAction FieldName="alttext" FieldNameType="fixed" ValueFrom="alt" />
     </Actions>
   </Rule>

3. In the administration console, create an index field named alttext. Enable the full-text searchable attribute for the index field.
4. Restart the parse and index services for the collection.
5. Recrawl or re-import documents so that they can be parsed and indexed again.