Hello Guys, I am having hard time figuring out how...

# android

[Somesh]

Hello Guys, I am having hard time figuring out how I can connect my Repository and `ViewModel`'s livedata in-case of @GET request and observe them in fragment.
I don't have this problem when the request type is @POST because I can use Transformation.switchMap on body and whenever the body changes repository's function gets invoked and emit value to the response live data something like this

val matchSetsDetail: LiveData<Resource<MatchDetailBean>> = Transformations.switchMap(matchIdLiveData) { matchId ->
        val body = MatchSetRequest(matchId)
        repository.getMatchSet(body)
    }

but in case of @GET request I have several query parameter the my View supplies

I have this retrofit API call in repository class and the code looks like this

fun checkInCheckOutUser(apiKey: String, userId: Int, status: String, latitude: Double, longitude: Double, checkedOn: Long): LiveData<Resource<BaseResponse>> = liveData {
        emit(Resource.Loading())
        try {
            val response: Response<BaseResponse> = ApiClient.coachApi.checkInCheckOutUser(apiKey, userId, status, latitude, longitude, checkedOn)
            if (response.isSuccessful && response.body() != null) {
                if (response.body()!!.isValidKey && response.body()!!.success) {
                    emit(Resource.Success(response.body()!!))
                } else {
                    emit(Resource.Failure(response.body()!!.message))
                }
            } else {
                emit(Resource.Failure())
            }
        } catch (e: Exception) {
            emit(Resource.Failure())
        }
    }

and ViewModel

class CheckInMapViewModel : ViewModel() {
    val checkInResponse: LiveData<Resource<BaseResponse>> = MutableLiveData()

    fun checkInCheckOut(apiKey: String, userId: Int, status: String, latitude: Double, longitude: Double, checkedOn: Long): LiveData<Resource<BaseResponse>>  {
        return repository.checkInCheckOutUser(apiKey,userId,status,latitude,longitude,checkedOn)
    }
}

Main problem is I want to observe checkInResponse but don't know how to pass repository's livedata same as I did with my post request above using Transformations.switchMap. Can anyone help me with this case?

[pavi2410]

You could write your VM as

class CheckInMapViewModel : ViewModel() {
    val _checkInResponse = MutableLiveData()

val checkInResponse: LiveData<Resource<BaseResponse>
    get() = _checkInResponse

    fun checkInCheckOut(apiKey: String, userId: Int, status: String, latitude: Double, longitude: Double, checkedOn: Long)  {
        _checkInResponse.value = repository.checkInCheckOutUser(apiKey,userId,status,latitude,longitude,checkedOn)
    }
}

and in Activity

checkInMapViewModel.checkInResponse(this) { /* observe */}

checkInMapViewModel.checkInCheckOut(...) // Refreshes livedata

[Somesh]

@pavi2410 Thanks for reply. As you can see my repository function emits a live data but with your approach it expecting Resource<BaseResponse>. I simply can not do _checkInResponse.value = repository.checkInCheckOutUser(apiKey,userId,status,latitude,longitude,checkedOn) because of this.

[kristianconk]

in my experience, repositories must not return livedata, your viewmodel validate repository's response and emit into livedata

[pavi2410]

Yeah, repository should be only for retrieving data, not observing them

[pavi2410]

@Somesh You can either do

_checkInResponse.value = repository.checkInCheckOutUser(...).value

or

_checkInResponse = repository.checkInCheckOutUser(...)

[pavi2410]

It, basically, is

livedata.value = anotherLivedata.value

or

livedata = anotherLivedata

[Bacho Kurtanidze]

what if you create mediator live data in view model and set returned liveData from repository as its source somethings like this. I'm facing same problem rn and I cant come up with better idea yet

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