Dagger inject Context in a ModelView

Question

I'm trying to inject the Context in my ModelView but I'm a little bit confused:

Here is my Module, I send him an Application for later use the context from this, but I don't know where it comes from this Application or how to take it:

@Module
class module {
    @Provides @Singleton fun appContext(application: Application): Context{
        return application
    }
}

And here is my Component:

@Component(modules = [module::class])
interface component {
    fun providesApplication(): Application
}

To finish I don't know how to inject this in my ViewModel because this don't have constructor to inject it.

How should I inject the context to my ViewModel?

why do you want to inject context to the ViewModel? – coroutineDispatcher Jul 22 '19 at 10:00 — coroutineDispatcher, Jul 22 '19 at 10:00

score 4 · Accepted Answer · answered Jul 22 '19 at 10:01

4

There is already build-in ViewModel with context, replace inheritance from ViewModel with AndroidViewModel

See: https://developer.android.com/reference/android/arch/lifecycle/AndroidViewModel

answered Jul 22 '19 at 10:01

Maksym V.

2,877
17
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And how I should replace this line: viewModel = ViewModelProviders.of(this).get(MainViewModel::class.java) because it jumps me an alert. – David Jul 22 '19 at 10:12

a_local_nobody · Answer 2 · 2019-07-22T10:30:23.540

1

alternatively, you could try something like this :

class YourViewModel @Inject constructor(context:Context) : ViewModel()

Merely a suggestion if nothing else works, hear me out...

var context: Context? = null

fun initViewModelWithContext(context: Context) {
    this.context = context
}

you could potentially do something like this as well, if you don't find a solution with dagger. all your functions can then use this local instance of context, and this ViewModel will be destroyed/created as it is needed so it won't be causing any memory issues

edited Jul 22 '19 at 10:30

answered Jul 22 '19 at 10:16

a_local_nobody

7,947
5
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Interesting... but then I should inject the a constructor instead of a Context? I don't know how to finish it. – David Jul 22 '19 at 10:20
The context is required, because I have a few fun who need it. However, I try what you say but the thing Is I need to make the builder and it usually done in the constructor. – David Jul 22 '19 at 10:26
I think what you are trying to made is inject a full constructor to my ViewModel right? – David Jul 22 '19 at 10:27

Dagger inject Context in a ModelView

2 Answers2