Drupal 8 version of this module is available for test !
This module is an add-on to the Search API which allows the indexing and searching of attachments.
The extraction can be done using :
Apache Tika Library
The Solr built-in extractor since the version 1.3.
Acquia Search since the version 1.4.
pdftotext for pdfs since the version 1.7
python pdf2text for pdfs since the version 1.7
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