好主意还是不好：用协程反应Kotlin

Question

i want to ask a good developers. Maybe anyone can better explaine. Somewhere in web i found that few authors used coroutines instead for example asynctasks . Just trying to improve myself . Here a small part of code which i used . Just want to know - it's good or no. If no - how to make it's better or maybe in final im using this in wrong way.

 fun demoCall(callback: OnResponse) {
       CoroutineScope(Dispatchers.Main).launch {
          val result = withContext(Dispatchers.IO) {
             Api.getResponse("GET", ApiConstants.test_endpoint)//networkOnMainThread exception if i will not use withContext
          }
          callback?.onResponse(result))
       }
  }

This example is work . But im not sure it's good usage. If back to past ,

getResponse

was in asyncTask. Call was same with annonymus callback. If to use this way is good , looks like i can use this part without callback ? Just like this

fun demoCall() {
 CoroutineScope(Dispatchers.Main).launch {
    val result = withContext(Dispatchers.IO) {
       Api.getResponse("GET", ApiConstants.test_endpoint)
    }
    //do anything with result
    //populate views , make new response etc.. 
}

will be very happy if any tell me - is it ok or no :) Regards

Answer 1

I prefer making asynchronous calls be seen like synchronous in caller's view using suspend keyword.

For example,

suspend fun demoCall(): String {
    return withContext(Dispatchers.IO) {
        Api.getResponse("GET", ApiConstants.test_endpoint) // let's assume it would return string
    }
}

and caller can use it

CoroutineScope(Dispatchers.Main).launch {
    val result = demoCall() //this is async task actually, but it seems like synchronous call here.
    //todo something with result
}