Robust offline functionality

[RobbotheGregg]

Offline mode is very temperamental in its current state.
Many trips have us travelling in areas without internet access and we loose all access to the app.

A toggle switch to force app offline would be beneficial to allow us to ensure we have all the info we need before actually going offline. I say an in app toggle so the app can make the needed downloads/configuration to ensure it has all it needs to go offline.

Also the ability to choose what information is stored locally. For example, I may only want the trip data, addresses, dates/times ect. We don't necessarily need the entire world map.

For conflicts with data entries when returning online, maybe a form can be shown to step through and choose which conflict wins etc.. or have rules that latest wins - global options for conflict resolution rules would be value adding here too.

Thanks for a great app! I am truly impressed with what you have built here 👌👌

[mauriceboe]

Thanks @RobbotheGregg, this is excellent feedback — and all three parts are now built and landing in 3.2.0:

• Force offline toggle — a switch under Settings → Offline that downloads everything first (trip data, documents and map tiles) and then takes the app offline, so you can be sure it has what it needs before you lose signal.
• Selective storage — you can leave map tiles out (they're by far the heaviest part) and pick which trips to keep on the device, so it's never "the entire world map" unless you want it.
• Conflict resolution — edits made offline are checked against the server when you reconnect; clashes are surfaced with a keep mine / keep theirs choice per item, plus a default rule (ask each time, always keep mine, or always keep the server version) if you'd rather not be asked.

It's all in #1380 if you'd like to follow along. Really glad you're enjoying TREK 👌