Hey everyone, I’m looking for the most idiomatic ...

# coroutines

[Stanislav Kral]

Hey everyone,

I’m looking for the most idiomatic way to group two “actions” under one cancellable scope (that "inherits" from another scope, read Android's viewModelScope ) so that I can wipe all in-flight work whenever my filter changes—rather than cancelling each Job? by hand.
Here’s what I’ve got today:

class MyViewModel : ViewModel() {
  private var loadNextPageJob: Job? = null
  private var refreshJob: Job?      = null

  fun onLoadNextPage() {
    loadNextPageJob = viewModelScope.launch {
      // …fetch next page, show retry SnackBar, recurse on retry…
    }
  }

  fun onRefresh() {
    refreshJob = viewModelScope.launch {
      // …fetch fresh data, toggle spinner, show error SnackBar…
    }
  }

  fun setFilter(filter: Filter) {
    // I want to cancel *all* running work here…
    loadNextPageJob?.cancel()
    refreshJob?.cancel()
    // …then apply the new filter
  }
}

I thought of creating a custom scope, but I am not sure how to properly "inherit" from viewModelScope

[Albert Chang]

You can create a job like this:

val job = Job(parent = viewModelScope.coroutineContext[Job])

and use viewModelScope.launch(job) {} so that all the launched jobs are the children of the job you created and calling job.cancel() will cancel all the children.

[Alexandru Caraus]

You can do a flow of filter, and collect latest