Don't instantly delete an unreferenced attachment

[hungrysnake]

Current behavior

when the note text with images is deleted, undoing the delete will only bring back the text, not the

Expected behavior

able to undo the deletion of images

Steps to reproduce

1. paste an image to a note
2. delete the line for the image
3. Ctrl-Z to undo

the text will come back but the image is not loaded because it is deleted in the filesystem

Environment

• Version : Boostnote 0.11.17
• OS Version and name : Win10

[ehhc]

I don't have a solution for this problem (i don't even know if there is a technical solution on how to do that..) but #3107 gives you 30 seconds to decide that you want to undo the change before the attachment is deleted :)
Maybe that's better than nothing :)

[hungrysnake]

just throwing some idea.
could it be implemented this way?
when the image is deleted, temporarily rename the file to image.jpg.deleted.
when undo is triggered, rename it back to image.jpg
after a while (2 days maybe) delete all the *.deleted files.

[ehhc]

the problem ist the last part: when and how do you crawl all folders with images/attachments in and delete unneeded ones? How do you trigger that job?

i think debouncing the deletion can be a good workaround. Maybe it's enough :)

[hungrysnake]

i think the triggering point would be the moment of closing the application because undo can't be done after app close anyway.
another point would be the moment of opening application to make sure if there is any temp file left over

[ehhc]

@hungrysnake at least the first idea dosen't work: after closing the app, the process is terminated. As far as i konw, there is no way to hook in at this point.
Scanning all notes at the start of the app (inclusive scanning the folders containing the attachments for all scanned notes) seems to be quite slow. Therefore the start of the app would be slowed down.. I don't know whether that's worth the benfefit of being able to undo changes..

[Flexo013]

@ehhc I'm not quite sure how it works in Electron, but I think it should be possible to hook in on process termination. Similar in how certain programs will ask you "Are you sure you want to exit?".

A force termination of the process would be harder to hook into, so in that case we do need some clean-up of these files.

---

To expand on @hungrysnake's suggestion: We could move the deleted image to a separate designated .deleted_images folder. If the user undos then we simply move the image back to the orginal location. Upon closing (or starting) of Boostnote we check the .delete_images folder and clean it up.

[Flexo013]

While this is now slightly mitigated I still think that the feature as I suggested in my previous comment would be really helpful.

It would solve #3203 for example.