'Promise<T>' is deprecated. Use CompletableDeferred instead

[lemkoleg]

The object Promise was marked as deprecated.
It is suggested to use CompletableDeferred instead.
Could you give an example of how to do this. Thank you.

[soywiz]

Sure. Can share a snippet of the code you are using with promises, to explain how to use CompletableDeferred in that context?

[lemkoleg]

fun RETURN_PROMISE_WITH_USER_OBJECT(): Promise<SomeUserObject?> = CoroutineScope(Dispatchers.Default + SupervisorJob()).async {
            withTimeoutOrNull(Constants.CLIENT_TIMEOUT) {
                // no suspend function return Promise for create SomeUserObject
                // and front-end login will decide whether to wait for the object or use a callback function

                return@withTimeoutOrNull SomeUserObject
            } ?: throw my_user_exceptions_class(
                l_class_name = "UserObject",
                l_function_name = "RETURN_PROMISE_WITH_USER_OBJECT",
                name_of_exception = "EXC_SYSTEM_ERROR"
            )
        }.toPromise(EmptyCoroutineContext)

[lemkoleg]

Sorry, I don’t know how to highlight the code so that it looks normal

[soywiz]

I have edited it for you. You can edit it and see how it worked. It is with triple backticks "```"

[soywiz]

For tha case just do not use the .toPromise and return the Deferred.

fun RETURN_DEFERRED_WITH_USER_OBJECT(): Deferred<SomeUserObject?> = CoroutineScope(Dispatchers.Default + SupervisorJob()).async {
            withTimeoutOrNull(Constants.CLIENT_TIMEOUT) {
                // no suspend function return Promise for create SomeUserObject
                // and front-end login will decide whether to wait for the object or use a callback function

                return@withTimeoutOrNull SomeUserObject
            } ?: throw my_user_exceptions_class(
                l_class_name = "UserObject",
                l_function_name = "RETURN_PROMISE_WITH_USER_OBJECT",
                name_of_exception = "EXC_SYSTEM_ERROR"
            )
        }

[soywiz]

And for other scenarios:

val deferred = CompletableDeferred<Int>()
callbackThatWillExecuteInOtherThread {
  deferred.complete(10)
}
return deferred

or supporting throwing exceptions:

val deferred = CompletableDeferred<Int>()
callbackThatWillExecuteInOtherThread {
  deferred.completeWith(runBlocking {
     if (something) error("An error")
     return@runBlocking 10
  })
}
return deferred

[lemkoleg]

thank you very much