How to instantiate a viewmodel which extends AndroidViewModel class

[yashasvigirdhar]

Hi,

First of all, thanks for open sourcing this library.

In my project, I've viewmodels which extend AndroidViewModel class, which means they want an
instance of application as a constructor parameter. I use the application context in viewmodel for two purposes:

• to get some an instance of my application class to further have access to my dagger applicationComponent field so that I can use field injection in my viewmodel. Something like this:

MyApplication.getInstance(application).applicationComponent.inject(this)

• to get a string resource
  (getApplication() as MyApplication).getString(R.string....

Hope that's clear.

I can't think of anyway to test this viewmodel without using Android instrumention/RoboElectric.

Do you have any ideas in mind?

[yashasvigirdhar]

okay, I read about it and got to know that it's a bad practice to resolve the resources in viewmodels.we should just be setting int resource id there.
So we can eliminate the second use there.

[yashasvigirdhar]

okay I read more about first thing :) , and got to know implementing a custom view model factory is the way to provide all the dependencies to viewmodel. So, it turns out that I can get rid of the context itself here. I am.gonna try it.

[jraska]

Hello yes, I would go for the factory yes. Here there is an example implementation: https://github.com/jraska/github-client/blob/master/core-android/src/main/java/com/jraska/github/client/core/android/ViewModelFactory.kt