[FIXED] ViewModel in Kotlin: Unresolved Reference

Issue

I am trying to implement ViewModel in a 100% Kotlin app. Every piece of documentation I can find says I want to use this to get the ViewModel instance:

ViewModelProviders.of(this).get(CustomViewModel::class.java)

According to the docs, I should be able to import this with:

import android.arch.lifecycle.ViewModelProviders

This import is unresolved though. I am using the following in my build file:

def androidArchVersion = '1.1.1'
implementation "android.arch.lifecycle:viewmodel:$androidArchVersion"
implementation "android.arch.lifecycle:livedata:$androidArchVersion"
annotationProcessor "android.arch.lifecycler:compiler:$androidArchVersion"
testImplementation "android.arch.core:core-testing:$androidArchVersion"

Why can't I access ViewModelProviders?

Solution

Include the following as a dependency:

implementation "android.arch.lifecycle:extensions:1.1.1"

The equivalent AndroidX dependency is:

"androidx.lifecycle:lifecycle-extensions:VERSION"

in where VERSION can be replaced for Current Stable, Beta or Alpha values given in this official link

This dependency is for both ViewModel and LiveData and thus would not require you to give separate dependencies for the same either; i.e. the first two dependencies indicated by you can be replaced by the aforementioned lifecycle extensions dependency.

Answered By - Supriya