Cross-browser support

[stlim0730]

I was trying to test some on-map interactivity features on Safari, to make sure nothing is Chrome-dependent. Safari failed to properly load the map.

Need to find out the reason and solution.

[stlim0730]

I found one of the potential reasons. I prefer let expression to var for variable assignment in Javascript because let has more specific local scope. However, Safari doesn't officially support the MDN standard regarding let expression (MDN let statement).

When I mechanically replaced all the let in my Javascript code with var, both Chrome and Safari failed to load the map correctly. The replacement might require more careful attention.

Currently, the only web browser we can confirm to be supported is Chrome.

[calo1]

If this persists .. lets add that to the readme to keep track

[brianashpugh]

I just did a quick browser check on the most recent versions of Safari and Firefox. Safari loaded the map correctly, but Firefox did not. There are some javascript errors in the console so it may be a quick fix.

We should consider a more serious browser compatibility audit too since Farmview users are more likely than average to be on outdated software.

[brianashpugh]

The Firefox issue is on this line:

let values = val.split(' ');

so almost definitely still the 'let' incompatibility. But I realized I was on a very old version of FF, and updating fixed the issue. We should still consider moving from 'let' to 'var' to support old FF and Safari versions.

[stlim0730]

I disagree that we should move from let to var declaration.
They have different behaviors or side effects where let gives us more specific scope of the declaration.
let is one of features in newer standard. I think Farmview should be more future-proof, rather than backward-compatible.