MVVM startActivityForResult

Question

When a view is clicked, startActivityForResult should be called. But I cannot call startActivityForResult in viewModel. How can I achieve it?

Answer 1

I have read the google samples here (https://github.com/googlesamples/android-architecture/tree/todo-mvvm-databinding) and find the solution:

1. create a interface to implement:

   public interface TaskItemNavigator {
       void openTaskDetails(String taskId);
   }
   

2. have a weak reference in view model:

   @Nullable
   private WeakReference<TaskItemNavigator> mNavigator;
   

3. implement it in activity:

   public class TasksActivity extends AppCompatActivity implements TaskItemNavigator{
       ...
       @Override
       public void openTaskDetails(String taskId) {
           Intent intent = new Intent(this, TaskDetailActivity.class);
           intent.putExtra(TaskDetailActivity.EXTRA_TASK_ID, taskId);
           startActivityForResult(intent, AddEditTaskActivity.REQUEST_CODE);
       }
   }