How I can use callback in Kotlin?

Question

I have View and one CircleShape , which should show toast in this View. And I use it in main Activity. This is my interface

interface OnClickListenerInterfa         


        

Answer 1

to use Kotlin callbacks , I use them in my api calls for success or failure use

create enum class for state

enum class APIState(val result: Boolean) {
SUCCESS(true),
FAILURE(false)}

use call back in fun

 private fun fetchFeesList(studentID:String,call:(APIState)->Unit){
 ... do stuff here , and use call(APIState.SUCCESS) or call(APIState.FAILURE) }

when calling function fetchFeesList , call it like

fetchFeesList(studentID){
        val res = it.result
        if(res){
            toast("success")
        }else {
            toast("failure")
        }
    }

for toast("message") , use Anko Lib from GitHub : - https://github.com/Kotlin/anko