Using relative paths should work. Can you please show me the relevant part of your .html file?

Please note that file paths on iOS are case-sensitive. So "Filters" is not the same folder as "filters".

Feel free to do that. There would be much more needed to implement this efficiently and for all supported languages. 

Just running a regex on the whole text on potentially every keystroke would not be how I'd approach this. 

Also, one of the biggest problems for me is how to do a touch-friendly UI for expanding/collapsing and have big enough touch targets on small iPhone screens while not interfering with text selection.

With Secure ShellFish, I'd recommend to add the server as an external folder to Textastic using the "Add External Folder…" command.

When you then open a file and edit it, Secure ShellFish should automatically upload your changes.

You can trigger a Save with an external keyboard using Cmd-S. Tapping the "…" button in the top right corner also triggers a save.

If that still doesn't upload the file, I would try if a reboot of your device helps. 

Let me know how it goes.

Using the "Share" command method I mentioned, you can select a specific app for different file extensions. So if you use share to open Textastic for .txt, and another app for .md for example, the system will remember this selection.

I also wish this would have a better UI - similar to the Mac, but that would be something Apple has to change.

In the Files app, open the context menu of the file and select "Share". Then select Textastic. From now on it should open files with the same file extension in Textastic.

Alternatively, you can use the "Open…" command in Textastic to pick a file using the Files user interface.

This is fixed in Textastic 10.5.2.

This is changed in Textastic 10.5.2:

The app no longer prompts users to connect to a Wi-Fi network when starting while Airplane mode is enabled. This behavior was removed by deleting UIRequiresPersistentWiFi from the app’s Info.plist.

This is fixed in Textastic 10.5.2. 

Thanks again for letting me know about this - I'm honestly not sure how I missed this - looks like it was like that for years 😬

Do you want to have the option to order the results when doing a filename search or when doing a file content search?

When doing a filename search, Textastic performs a fuzzy search and displays the files with the best matching name first, so a sort order doesn't make a lot of sense.

So I assume you are asking for sorting the results of a file content search?