Golang - GoMobile tool for cross platform slices of struct return type

Question

During the journey of cross-platform mobile app development, I came across Golang which is having a GoMobile command line tool which generates language bindings that make it possible to call Go functions from Java and Objective-C. However, there are some restriction on the types used in an exported function/method as documented here: https://godoc.org/golang.org/x/mobile/cmd/gobind#hdr-Type_restrictions

So any idea about the work in progress to support slices of struct (Array of struct) in the data types used in exported functions

Answer 1

A workaround with String as an example:

type StringCollection interface {
    Add(s string) StringCollection
    Get(i int) string
    Size() int
}

// TODO solve this with generics
type StringArray struct {
    items []string
}

func (array StringArray) Add(s string) StringArray {
    array.items = append(array.items, s)
    return array
}

func (array StringArray) Get(i int) string {
    return array.items[i]
}

func (array StringArray) Size() int {
    return len(array.items)
}

Usage in go:

func GetExampleStringArray() *StringArray {
    strings := []string{"example1", "example2"}
    return &StringArray{items: strings}
}

On Android you can use this extension to convert it to a List<String>:

fun StringArray.toStringList(): List<String> {
    val list = mutableListOf<String>()
    for (i in 0 until size()) {
        list.add(get(i))
    }
    return list
}

fun main() {
    GoPackage.getExampleStringArray().toStringList()
}