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NativeScript Core

Function Pointers

To create a native function pointer from a JavaScript function you must use the interop.FunctionReference() constructor which accepts a single parameter - a JavaScript function. You must keep the returned object alive as long as the native side would need it.

Example:

@interface NSMutableArray
+ (instancetype)arrayWithArray:(NSArray *)array;
- (void)sortUsingFunction:(NSInteger (*)(id, id, void *))compare context:(void *)context;
@end
var array = NSMutableArray.arrayWithArray([1, 3, 2, 4]);

array.sortUsingFunctionContext(new interop.FunctionReference(function (a, b, ctx) {
    return a - b;
}), null);

console.log(array); // [1, 2, 3, 4]

When a function pointer is marshalled to JavaScript it is exposed as a JavaScript function.