Simple sync methods

[MihanEntalpo]

This thread is a continuation of the discussion started in this PR: #2207

The problem: the need to sync habits with external systems in order to use automation, scripts, and similar tools.

An easy solution would be to make the backup frequency configurable, so that the database backup could be synced via Syncthing or some other tool available. This method was rejected as it is not directly related to backup functionality.

Now I want to discuss possible ways to implement syncing of habit states with remote systems

I put the methods I’ve come up with into a table:

Method	Details	Pros	Cons
Online web app + sync protocol	Create web-based app, with an online account, and synchronize with it	It would satisfy many users needs, according to feature requests it's quite demanded feature to use multiple devices or even web-app	It would be too hard, and as Loop is simple stand-alone offline app, it would take enormous amount of work, and eventually it would be a completely different app
Automatic sync database file to some public folder	Something like backups, but make a copy of database to the same file over and over again, and sync it via syncthing	Very simple, can be used by lots of scenarios	Only one-direction sync, cannot automatically update database of the app. The minimum dump frequency (15 minutes) may not be sufficient for some users. The setting "Sync to public folder" would be unclear or confusing for non-technical users
Automatic backup with configurable period	The idea is proposed in PR	Simple, "kills two birds with one stone" - backups & sync	If the frequency is set to every 15 minutes, it may be too frequent for normal backups
Tasker/Automate plugin to export database to json	Loop already has Tasker plugin integrations, and another plugin can be added: a handler that exports the entire database in JSON format, so TaskerAutomate could acquire it, and do something with it (send somewhere, copy, etc.)	Not so hard solution, doesn't require any web/third-party systems to synchronize	Has security problem, as any app could use such plugin handle, but this can be addressed: when Automate try to add plugin, configuration window appears (implemented in Loop), and so, this window can have button "Grant permission" which would populate a text parameter field with a token, saved in preferences or database, and on each call of plugin handle, this token is checked. So, no other app could access this handle without user granting access manually.
Tasker/Automate plugin to Event of "Habit state changed"	When user changes some habit's state, event is fired, and Tasker/Automate can listen for it, and make some actions based on it.	Gives more granularly access	Synchronization would have to be implemented using Tasker/Automate scripts, which could be quite cumbersome

As I, and some other users NEED syncing functionality, lets discuss available methods, maybe propose another, which I've didn't realize.

Right now I'm looking forward at "Tasker/Automate plugin to export database to json", but also, will make option to copy database to a public folder on my own fork, as a temporary solution.

@iSoron I invite you to this thread :)