Full text search is the core App of a full-text search framework for your Nextcloud. To have it operate, and get content indexed, some other Apps are needed:

• Some Providers Apps to extract content from your Nextcloud.
• A Platform App that communicate with a search platform (ie. Elastic Search, Solr, ...) in order to index the content provided by the Providers.
  Note: There is no limit to the number of Platform-App to be installed, however only one can be selected from the Admin Interface

List of Providers Apps:

• Files_FullTextSearch - Index your files.

List of Platform Apps:

• FullTextSearch_ElasticSearch - Use Elasticsearch to index content.

Documentations

• Basic Installation to index your files in Elasticsearch