Configuration of file content mining is hard and/or not documented.
I'm really sorry to ask directly in here, but I was not able to find a solution via stackexchange/websearch or the online-documentation.
OS: Ubuntu 18.04 LTS (fresh install, everything is default)
~> gnome-shell --version GNOME Shell 3.28.3 ~> nautilus --version GNOME nautilus 3.26.3
Since Ubuntu 18.04 the gnome dash search does not search for files contents, but only in it's names (and maybe metadata or so). I believe that I found the reason for that:
~> tracker daemon -w Ressourcen-Aktualisierungen der Datenbank werden nun überwacht Alle Eigenschafte »nie:plainTextContent« werden ausgelassen Drücken Sie Strg+C zum Anhalten
In line 3 it says that »nie:plainTextContent« is being skipped (german output). I wonder why. I had no problems with this feature and would like to re-enable it, but I didn't find anything. I tried config files and searched in gconf/dconf, tried a few things but nothing worked. It seems like the nie:plainTextContent is the Element that has the information I want to search for:
~> tracker extract ~/watched_folder/file.pdf @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . @prefix nie: <http://www.semanticdesktop.org/ontologies/2007/01/19/nie#> . @prefix nfo: <http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#> . <file:///home/user/watched_folder/file.pdf> nfo:pageCount 51 ; nie:title "Lecture_File" ; a nfo:PaginatedTextDocument ; nie:plainTextContent "long text from the pdf" # this is what I want to search in!
So the extraction works, but it is either not extracted or searched in. How can I enable this?