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How to provide arguments like this `Callback` in Fragment using HILT ```class PostAdapter @Inject...
# dagger
k
How to provide arguments like this 
Callback
in Fragment using HILT
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class PostAdapter @Inject constructor(
    @ApplicationContext private val context: Context,
    private val callback: Callback //HOW THIS CAN BE PROVIDED FROM FRAGMENT
) : ListAdapter<Post, PostAdapter.Holder>(DIFF) {

  /.../

   interface Callback {
        fun onClick(post: Post)
    }

}
r
Depends on what that callback does
Do you want your 
Fragment
to implement this 
Callback
?
j
Why do you need the context? You can get the context from the view
👍 1
k
@Rafal yes i want to implement it in fragment
@Javier yes, i can skip context but Callback should be implemented by fragment and @Inject using Hilt
r
then the only thing I can think of is to make a method that could provide an 
Optional<Callback>
in the fragment scoped module
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@Provides
fun provideCallback(fragment: Fragment): Optional<Callback> = if(fragment is Callback) Optional.of(fragment) else Optional.empty()
k
@Rafal looks like it would work
but this maybe too much for this case
i am thinking to create Adapter instance manually in fragment
r
well, with your constructor arguments this sounds like a better option
j
I don't think you should use DI for this btw
r
+1 to above. You should not use DI for callback.
d
@Rafal You don't need to wrap fragment with Optional. You can just bind fragment to Callback type.
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@Binds
fun bindCallback(fragment: Fragment): Callback
r
how does Dagger will know if the fragment actually implements this 
Callback
d
From this binding
This the common use of 
@Binds
k
@dawidhyzy looks cool, so i don’t have to provide any implementation ?
because @Binds is going to be 
abstract
if i’m not wrong
and it would be better to add parameter fragment more specific like @Rafal You don't need to wrap fragment with Optional. You can just bind fragment to Callback type ???
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@Binds
fun bindCallback(fragment: LoginFragment): Callback
r
It wont work with hilt because you cant bind concrete fragment instance
If you install your module inside the FragmentComponent you can only refference the 
Fragment
class
You will get the error that you cant bind instance from class that doesnt implement given interface
You could do that in dagger-android
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