Syncing of data

[ltseng]

Allow the user to send and receive information to and from the server at various events.

References

Syncing of Data Spec Ruxandra pres Garo Syncing Mural Garo Summary

MVP breakdown

### Tasks
- [ ] https://github.com/techmatters/terraso-product/issues/990
- [ ] https://github.com/techmatters/terraso-product/issues/918
- [ ] https://github.com/techmatters/terraso-product/issues/1037
- [ ] https://github.com/techmatters/terraso-product/issues/1115
- [ ] https://github.com/techmatters/terraso-mobile-client/issues/2278
- [ ] https://github.com/techmatters/terraso-mobile-client/issues/2279
- [ ] https://github.com/techmatters/terraso-mobile-client/issues/2283
- [ ] https://github.com/techmatters/terraso-mobile-client/issues/2291
- [ ] https://github.com/techmatters/terraso-mobile-client/issues/2292
- [ ] https://github.com/techmatters/terraso-mobile-client/issues/2293
- [ ] https://github.com/techmatters/terraso-mobile-client/issues/2294
- [ ] QA
- [ ] https://github.com/techmatters/terraso-product/issues/1131

### Old Tasks - wont use these designs for MVP
- [ ] https://github.com/techmatters/terraso-product/issues/484
- [ ] https://github.com/techmatters/terraso-product/issues/485
- [ ] https://github.com/techmatters/terraso-product/issues/486
- [ ] https://github.com/techmatters/terraso-product/issues/487
- [ ] https://github.com/techmatters/terraso-product/issues/488
- [ ] https://github.com/techmatters/terraso-product/issues/489

Acceptance Criteria

Triggers

• [x] synchronize data on startup for all sites and projects I belong to (uploads and downloads new data).
• [x] push client-side updates with the cloud immediately if online
  • [ ] pull if there's an error
• [x] push and pull data when device goes from offline to online
• [ ] pull periodically (engineer discretion - 5 mins while app is in foreground?)

Sync Behavior

• [ ] the client will send the values of the entire site in which the user has modified a field since last sync
  • [ ] the server will unconditionally accept these values
  • [ ] the server will create a log entry with the values the client sent and the time that they were received (we won't immediately do anything to expose those log entries, but they'll be available via support request and could be exposed in future)
  • [ ] Push changes at a field level!

Nongoal:

• [ ] for MVP, we will NOT need to keep track of when the user has input data
• [ ] We will not try to recreate a site that has been deleted
• [ ] We will not try to add data to a site that has been moved to a project where the contributor does not have permissions

[DerekCaelin]

We plan to have a sync (with updated API calls) every time the data changes: slack conversation

[DerekCaelin]

Garo notes:

we discussed several possible enhancements to this workflow, but agreed that since: we expect data conflicts will be edge cases anyway, and we can advise users to record data for a site on only one device we can start with the above implementation, and revisit which enhancements make sense if we start receiving reports of user frustration due to data conflicts

[DerekCaelin]

Sync is heavy Option

Pull button:

• "pull" button in the footer menu
• go to screen that describes the behavior
• pros: relatively low effort,
• cons: trains the user to expect a behavior that we might not want long term
• cons: might need to rearrange the settings menu (bring back side drawer)

Do nothing:

• don't have a periodic refresh
• later, implement a cheaper pull
• cons: not really a great experience to have to start and stop the app again.

Research:

• optimize sync size as part of MVP
• pros: ideal to not have the user worry about syncing at all. it just works
• cons: unknown effort