Get data from Callback using Coroutine 🧠

3 great ways to get data from a callback using a coroutine

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0️⃣ Define a result class:

Result

sealed class Result<T> {
    data class Success<T>(val result: T) : Result<T>()
    data class Failure<T>(val error: Throwable) : Result<T>()
}

FOREWORD: example based on Firebase Auth Send SignIn Link and DataStore.

1️⃣ FIRST method — just getting data from a callback:

suspendCoroutine

override suspend fun sendSignInLinkToEmail(
    email: String,
    actionCodeSettings: ActionCodeSettings
) = suspendCoroutine<Result<Boolean>> { continuation ->
    auth.sendSignInLinkToEmail(email, actionCodeSettings)
        .addOnSuccessListener { continuation.resume(Result.Success(true)) }
        .addOnFailureListener { continuation.resume(Result.Failure(it)) }
}

2️⃣ SECOND method — get data from callback with cancellation option:

suspendCancelableCoroutine

override suspend fun sendSignInLinkToEmail(
    email: String,
    actionCodeSettings: ActionCodeSettings
) = suspendCancellableCoroutine<Result<Boolean>> { continuation ->
    auth.sendSignInLinkToEmail(email, actionCodeSettings)
        .addOnSuccessListener { continuation.resume(Result.Success(true)) }
        .addOnFailureListener { continuation.resume(Result.Failure(it)) }
}

RECOMMENDATION: suspendCoroutine VS suspendCancelableCoroutine always use — suspendCancelableCoroutine.

3️⃣ THIRD method — get data from callback with the ability to run suspend functions:

CompletableDeferred

PS. Vel_daN: Love what You DO 💚.