MKCoordinateSpanMake is undefined

[TJ]

Hey all,

I'm working on porting some map code from Objective-C to NativeScript and I ran into this issue. Basically console.log( typeof MKCoordinateSpanMake ) logs undefined, and I'm not sure why, because my other mapping classes are all available. Here's the iOS API docs on it: https://developer.apple.com/library/mac/documentation/MapKit/Reference/MapKitFunctionsReference/index.html#//apple_ref/c/func/MKCoordinateSpanMake.

Thanks,
TJ

[Pana]

Hi,

MKCoordinateSpanMake is an inline function. This means it has its implementation defined in its header, but does not emit native code in the native library. Similar functions are not available in NativeScript. The function is declared as:

NS_INLINE MKCoordinateSpan MKCoordinateSpanMake(CLLocationDegrees latitudeDelta, CLLocationDegrees longitudeDelta)
{
    MKCoordinateSpan span;
    span.latitudeDelta = latitudeDelta;
    span.longitudeDelta = longitudeDelta;
    return span;
}

Anytime you use that function the native compiler will replace your C or Objective-C code with the function's implementation. However NativeScript does not translate the C code there to JavaScript. If you want to use it it would be best to write your own JavaScript utility function that does something like:

function MKCoordinateSpanMake(latitudeDelta, longitudeDelta) {
    return { latitudeDelta: latitudeDelta, longitudeDelta: longitudeDelta };
}

When the so created JavaScript object is used in a function that expects MKCoordinateSpan it will be marshaled to a C struct on the native side. There are still differences though the JavaScript does not support providing arguments by value.

In addition we are currently working on documentation for the iOS specific APIs and the inline functions topic will be included.

Regards,
Pana
Telerik

 

 

[TJ]

Hi Pana,

Thanks for the thorough answer. I appreciate it.

TJ