Is there already any multiplatform solution to show a location on an external map. Something that yo...

# multiplatform

[Michael Paus]

Is there already any multiplatform solution to show a location on an external map. Something that you would do in Android via https://developers.google.com/maps/documentation/urls/android-intents

[Alejandro Moya]

that’s platform specific, I don’t think that there will be anything like that available in multiplatform

[Alejandro Moya]

you can create a method on each platform to do that and have an expect on the commonMain, that way you’ll be able to do it

[Michael Paus]

If I can do it via expect/actual then anybody could have already done it and that’s what I was asking for. Just trying to avoid duplicate work. (Besides I don’t know how to do that on iOS.)

[Alejandro Moya]

fun openMaps(lat: Long, lon: Long) {
    if (UIApplication.sharedApplication.canOpenURL(
            NSURL.URLWithString("comgooglemaps://")!!)
    ) {
        UIApplication.sharedApplication.openURL(
            NSURL.URLWithString(
                "comgooglemaps://?saddr=&daddr=$lat,$lon&directionsmode=driving"
            )!!
        )
    }
}

[Alejandro Moya]

using code from: https://stackoverflow.com/questions/32039816/how-to-open-google-maps-to-show-route-using-swift

[Alejandro Moya]

that would be the ios implementation on multiplatform, I would first check if there’s access to the shared application from the library

[Alejandro Moya]

the reference on the maps urls for ios: https://developers.google.com/maps/documentation/urls/ios-urlscheme

[Alejandro Moya]

@Michael Paus I’ve been reading and you can’t access the app from a framework on ios, I think the same applies to android, this means you should pass the application object on ios and the context on android, you can achieve this by using typealias and create a common ApplicationObject type

[Alejandro Moya]

actual typealias APPObject = UIApplication

fun openMaps(appObject: APPObject, lat: Long, lon: Long) {
    if (appObject.canOpenURL(
            NSURL.URLWithString("comgooglemaps://")!!)
    ) {
        appObject.openURL(
            NSURL.URLWithString(
                "comgooglemaps://?saddr=&daddr=$lat,$lon&directionsmode=driving"
            )!!
        )
    }
}

[Alejandro Moya]

that would be the ios implementation

[Michael Paus]

@Alejandro Moya Many thanks. I’ll give that a try as soon as I can.

[Michael Paus]

Ohh, I just realize that this solution will probably not be usable in general. If I understand the docs correctly this would require the user to have the Google Maps app pre-installed on the device, right? My original question was “… to show a location on an external map.” and I gave the Google Maps example because that is what you would use on Android. On iOS I would instead use whatever is normally used to show a map on such a device without having anything specific being pre-installed by the user. Sorry for the confusion. 😢

[Alejandro Moya]

you can change the url in the code to match the apple one: https://developer.apple.com/library/archive/featuredarticles/iPhoneURLScheme_Reference/MapLinks/MapLinks.html

[Alejandro Moya]

that’s the reference for apple maps

[Alejandro Moya]

something like "<http://maps.apple.com/?ll=$lat,$lon>"

[Michael Paus]

Ahh, so the code above remains the same and only the URL changes, right?

[Alejandro Moya]

fun openMaps(appObject: APPObject, lat: Float, lon: Float) {
    if (appObject.canOpenURL(
            NSURL.URLWithString("<http://maps.apple.com/>")!!)
    ) {
        appObject.openURL(
            NSURL.URLWithString(
                "<http://maps.apple.com/?ll=$lat,$lon>"
            )!!
        )
    }
}

[Alejandro Moya]

fixed the lat and lon types as they will be Float

[Michael Paus]

It works. With the click of a button I can move to the iOS map at the given location in a multiplatform app.

[Michael Paus]

One question remains though. How can I get back to my app after I am done with the map?

[Alejandro Moya]

that’s regular iOS navigation, the person will switch apps to go back, same as with android