Step #6: Saving the Report

Now, we can wrap all this up, saving the report to the desired location.

First, add a new constructor parameter to RosterMotor, so we can get access to a RosterReport instance:

class RosterMotor(
  private val repo: ToDoRepository,
  private val report: RosterReport
) : ViewModel() {

This will require a change to its corresponding line in ToDoApp to get() the second parameter:

    viewModel { RosterMotor(get(), get()) }

Then, add this function to RosterMotor:

  fun saveReport(doc: Uri) {
    viewModelScope.launch {
      report.generate(_states.value.items, doc)
    }
  }

Here, we launch() our generate() coroutine, supplying that list of items from the current RosterViewState, along with the Uri identifying where we want the report to be written.

Next, in RosterListFragment, modify the createDoc property to call saveReport() on our RosterMotor:

  private val createDoc =
    registerForActivityResult(ActivityResultContracts.CreateDocument()) {
      motor.saveReport(it)
    }