ViewModel

ViewModel

   private val vendorDetailsRepo = VendorDetailsRepo()
    private val _vendorType: MutableLiveData<Vendor> = MutableLiveData()
    val vendorType: LiveData<Vendor>
        get() = _vendorType

    var vendor: LiveData<Result<Vendors>> = _vendorType.switchMap { vendor ->
        vendor.ifExists {
            liveData(context = viewModelScope.coroutineContext + Dispatchers.IO) {
                emit(vendorDetailsRepo.getVendorDetails(it))
            }
        }
    }

    fun setVendorType(vendorType: String) {
        val update = Vendor(vendorType)
        _vendorType.value = update
    }

    data class Vendor(val vendorType: String) {
        fun <T> ifExists(f: (String) -> LiveData<T>): LiveData<T> {
            return if (vendorType.isBlank()) {
                AbsentLiveData.create()
            } else {
                f(vendorType)
            }
        }
    }