elm-lang/geolocation

Get location data from Elm

Geolocation in Elm

Your client code is running on someone's device somewhere in the world. This library helps you find out where that device happens to be. If you are lucky, it may even tell you how fast the device is moving!

It is based on the JavaScript Geolocation API. You can read about how to use libraries with tasks and subscriptions in guide.elm-lang.org, particularly the section on The Elm Architecture.

geolocation's Issues

Publish to elm package registry

Looks great and useful! Can you publish it to the registry?

Need help with Task Type

I really could not get Geolocation.now working.

import Geolocation  exposing ( Location )
import Task

update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
    case msg of
        Msgs.SubscribeGeolocation ->
          ( model ,
            Task.attempt processGeolocation Geolocation.now
          )

processGeolocation : Result x a -> Msg
processGeolocation res =
  case res of
    Geolocation.Location location -> Msgs.SaveLocation location
    _ -> Msgs.Submit

Compiler tells me

Cannot find pattern `Geolocation.Location`.

Can someone assist? I'm really stuck.

Newest Safari no longer working with default options passed by Native.Geolocation#fromOptions

With the latest iOS update (10.3, is working with 10.2 - I tested this with multiple devices), Geolocation.now stopped working with default options. Don't know how long this hasn't been working with macOS Sierra, but it certainly doesn't work with 10.12.5. Geolocation.now with default options works in Chrome desktop and mobile, but in Safari it fails.

The cause of the problem is with the default options and the timeout setting:

function fromOptions(options)
{
	return {
		enableHighAccuracy: options.enableHighAccuracy,
		timeout: options.timeout._0 || Infinity,
		maximumAge: options.maximumAge._0 || 0
	};
}

Having timeout = Infinity immediately returns an error in the latest Safari across all platforms. In all the newest versions of Safari, this works exactly the same as passing timeout "0".

This can be tested easily by this snippet:

navigator.geolocation.getCurrentPosition(() => {}, (err) => { console.log(err)}, { timeout: Infinity})

It outputs just the next moment:
[Log] PositionError {code: 3, message: "Timeout expired", PERMISSION_DENIED: 1, POSITION_UNAVAILABLE: 2, TIMEOUT: 3}

Note that not passing any options works just fine with Safari and every other browser I tested:

navigator.geolocation.getCurrentPosition((result) => {console.log(result)}, (err) => { console.log(err)})

[Log] Geoposition {coords: Coordinates, timestamp: 519569198545}

I've checked MDN documentation once again (https://developer.mozilla.org/en-US/docs/Web/API/PositionOptions) and it does say that default option for timeout is Infinity. Seems like Apple decided to do something differently.

Anyway, with current implementation, unspecified (default) options just break the Geolocation API. Is it possible not to pass timeout set to Inifinity when talking to JS?

Why not a Time?

The timeout and TTL are specified using plain integer values. The docs specify a unit (yay!), but Time encodes it in a type. Is there some design constraint that makes Time undesirable here?

Geolocation.Options takes unitless values instead of Times

The record for Geolocation.Options has the following structure:

type alias Options = 
    { enableHighAccuracy : Bool
    , timeout : Maybe Int
    , maximumAge : Maybe Int
    }

The documentation specifies these values are in milliseconds. I'm curious why this isn't implemented using a Time instead. Wouldn't it reduce mistakes to use an interface that encodes the unit as well as the value?

-- unitless integers
{ defaultOptions | maximumAge = Just 30000 }

-- Times
{ defaultOptions | maximumAge = Just (30 * Time.second) }

(moved from #9)

Need to be able to handle PermissionDenied on changes

Am I missing something obvious?

Update to elm 0.19

Are there plans to upgrade this package to 0.19 ? Or has it been renamed somewhere else ?