How to get lifecycle.coroutineScope with new androidx.lifecycle:*:2.2.0-alpha01

Question

On 7th May, 2019 androidx.lifecycle:*:2.2.0-alpha01 was released announcing:

This release adds new features that adds support for Kotlin coroutines for Lifecycle and LiveData. Detailed documentation on them can be found here.

On documentation it's mentioned that I can get the LifecycleScope:

either via lifecycle.coroutineScope or lifecycleOwner.lifecycleScope properties

But it seems that I'm not able to find none of them. My current dependencises are:

def lifecycle_ver = "2.2.0-alpha01"
implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_ver"
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_ver"
implementation "androidx.lifecycle:lifecycle-common-java8:$lifecycle_ver"

implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.2.1'
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.2.1'

What may be the cause and how do get these apis?

Parmer

you can find the relevant versions here , mvnrepository.com/artifact/androidx.lifecycle/… , mvnrepository.com/artifact/androidx.lifecycle/… , mvnrepository.com/artifact/androidx.lifecycle/… – Linnie

Answer 1

I actually spent a couple hours trying to figure this out myself and it turns out it is in a new package that only exists as of the alpha. Add this and you should be good to go.

implementation "androidx.lifecycle:lifecycle-runtime-ktx:$lifecycle_ver"

Turquoise

Are you sure you did that exact line? I pulled up the source for it and have my own code running with it using lifecycleScope. What is it doing when you add it and try to reference lifecycleScope from a lifecycleOwner? – Turquoise

Even in an activity you should be able to do lifecycle.lifecycleScope since the activity is a lifecycle owner. What error is it giving you when you add the runtime-ktx dependency? – Turquoise

Thanks, works for me. Just use lifecycleScope.launch {...} from acrivity – Grandchild

My bad, didn't noticed -ktx at end, you should also edit the answer and mention the same. Wasted a whole day :p – Parmer

OMG. I'm searching for this for hours! This works. (The jetpack / ktx documentation is absolutely miserable. So many different sites but none shows a clear list of available packages and versions. Shame on you jetpack team!) – Dottie

Source: developer.android.com/topic/libraries/architecture/… – Yarn

How come I still fail to get it ? I tried it for this : androidexplained.github.io/android/ui/2020/10/21/… . For some reason, no matter what I add to gradle, I can't get lifecycleScope to be used at all... – Felishafelita

Answer 2

The accepted answers is working, but I'm misused for the first time, so I'm trying to make it clear, the current version of lifecycle is "2.1.0" and lifecycleScope, and ViewModelScope is not available in this version, to get them use

For ViewModelScope,

use androidx.lifecycle:lifecycle-viewmodel-ktx:2.1.0-beta01 or higher.

For LifecycleScope,

use androidx.lifecycle:lifecycle-runtime-ktx:2.2.0-alpha01 or higher.

at this time 2.4.1 is available.

Gid

Answer 3

Try this line of code in Build.Gradle (App Level)

implementation("androidx.lifecycle:lifecycle-runtime-ktx:2.2.0")

Flyn

Answer 4

I've just added this two lines of code to my build.gradle (App) and that worked like a charm. I can import lifecycleScope without any problems.

implementation 'androidx.navigation:navigation-fragment-ktx:2.5.2'
implementation 'androidx.navigation:navigation-ui-ktx:2.5.2'

Tenorrhaphy