Missing weather when using GPS

[clach04]

I'm missing weather when GPS has not been on for (~16 hours), and enabling GPS fixes the issue. This is an idea for a feature, assuming I've diagnosed the problem correctly ;-)

Most of the time I set config to the location I care about, I.e. Location override is NOT left blank. My use case is I don't travel very far, very often, so I always want to see "home" weather. I also don't turn the GPS on that much.

When I travel I'll often leave it blank (to indicate Using GPS. ) but sometimes GPS will be off (e.g. saving power) I'll forget to re-enable. This ends up with blank weather information, force-fetching does NOT fix the issue. Have to re-enable GPS.

Idea is that if Location override is left blank, use GPS as per current behavior to get location, then:

1. Use (browser) local storage to save that information, if the location is the same as current cache leave alone.
2. If GPS lookup fails, use cache location information

For me this would work great for my use case.

I'm not sure if this would work for everyone, if not this approach would also need a new "cache location" option added to the config page.

Seeking feedback :-)

[clach04]

Main logic located in

forecaswatch2/src/pkjs/weather/provider.js

Line 114 in a84a3a7

WeatherProvider.prototype.withGpsCoordinates = function(callback) {

Ideas:

1. Add local storage cache (maybe with bounding box for when to update cache?)
2. Use Infinity for maximum age instead of 10k milliseconds (10 seconds)

[clach04]

I experimented with number 2 above with clach04@16b5cb0 and been running for a few days and this does not work (at least on my Android 10 device).

Which leaves number 1 with some sort of delta offset/bounding box to avoid updating the cache EVERY time . Updating cache may not be that terrible, we record the last successful pull already:

https://github.com/mattrossman/forecaswatch2/blob/a84a3a79753fe6dddfa6d066b8b1db4df7c20fc7/src/pkjs/index.js#L13C57-L13C57

forecaswatch2/src/pkjs/index.js

Line 151 in a84a3a7

localStorage.setItem('lastFetchSuccess', JSON.stringify(fetchStatus));

in lastFetchSuccess.time, idea is to add a new attribute to:

forecaswatch2/src/pkjs/index.js

Line 143 in a84a3a7

var fetchStatus = {

var fetchStatus = {
    time: new Date(),
    id: provider.id,
    name: provider.name
}

[clach04]

Finally got some time to spend on this. I have a prototype branch https://github.com/clach04/pebble-forecaswatch2-fcsw2-fcw2/tree/issue69_cached_gps_location

It unconditionally caches GPS location, and then uses that on a GPS lookup failure.

Possible improvements:

1. add an option to enable/disable this behavior? I personally always want this on.
2. do not update cached location if the new location is "close" to the cached location, via some config option? Not sure if there are negative implications for updating local storage on each GPS read.