I just installed EOS, BTRFS, fresh install. I disabled Baloo.
Created a text file and downloaded a PDF book (that has text that can be copied) and an html.

I noticed that in Dolphin I can search content inside text files and html files. But not PDF.
I remember I read there is something to do this (a service, an addon?) I wonder if I got it right.
Is there any way to let KDE treat PDF as text and html files so I can search content in PDF (without installing Recoll, or any indexing app or using Baloo)?

Your kind help will be highly appreciated.
Thank you.

Search has been a mess since....forever. In short, good luck with that. I personally use pdfgrep for a quick search for text in pdf files. Unless I'm missing something, Recoll is still my best gui option. As search tool overall. https://imgur.com/a/P46bsIa

Thank you fro your replly, and sorry for late response.

OK... can I make Dolphin use recoll for searching for file content?
I installed kio_recoll but couldn't get it to work.

Any ideas?

Hello, I have installed KFind and call it from Dolphin, instead of using the "classic" search tool.
The results of a research are significantly different since I have many kinds of text-files (odt, docx, pdf, MD, html[and several markup formats] on my drive). I'm not sure about PDFs.
Will try out this evening.

Kfind can't search pdf's. No, you can't put recoll in the dolphin more search options thingy. Best option is to create a service menu if you want it in Dolphin itself. I quickly made the one in the screenshot. Strange thing is that I couldn't launch the program as such. So, I created a keybinding for it first and used xdotool to launch it.
Like so:

[Desktop Entry]
Type=Service
Icon=edit-find
X-KDE-ServiceTypes=KonqPopupMenu/Plugin
MimeType=all/all;
Actions=Search with Recoll
X-KDE-Priority=TopLevel
#X-KDE-Submenu=
Encoding=UTF-8


[Desktop Action Search with Recoll]
Name=Search with Recoll
Icon=edit-find
Exec=xdotool key ctrl+y

https://imgur.com/a/wnMvnOr

Ps: I searched for a recoll plugin for krunner. But the one I found wasn't usable. So yeah, a servicemenu is the closest you'll get I guess.