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Action status

All actions have a status property of type ActionStatus, that provides information about the action execution.

You can read the action status at any point in time. The status object is immutable, so it will always reflect the state of the action at the time you read it.

var action = MyAction();

var status = action.status;
print(status);

dispatch(action);

var status = action.status;
print(status);

Has the action completed?​

You can use action.status.isCompleted to check if a dispatched action finished. It will be false if the action is still running, or if it hasn't been dispatched yet.

You can use action.status.isCompletedOk to check if a dispatched action finished without errors (in more detail, if the action methods before and reduce finished without throwing any errors).

You can use action.status.isCompletedFailed to check if the action finished with errors.

An example:

var action = MyAction(); 
await store.dispatchAndWait(action);
print(action.isCompletedOk);

Better yet, you can get the status directly from the dispatchAndWait method:

var status = await store.dispatchAndWait(MyAction());
print(status.isCompletedOk);

Getting the action error​

If the action finished with an error, you can get the original error:

var error = action.status.originalError;

That's called an "original error" because it's the error that was originally thrown by the action's before or reduce methods. However, this error might have been changed by the action itself, by the action's wrapError() method.

For this reason you can also get the "wrapped error":

var error = action.status.wrappedError;

Up until which point did the action run?​

You can also use the status properties to check if the action has finished running the before, reduce, and after methods:

var status = await dispatch(MyAction(info));
print(action.status.hasFinishedMethodBefore);
print(action.status.hasFinishedMethodReduce);
print(action.status.hasFinishedMethodAfter);

Use cases​

The action status is useful mainly in testing and debugging scenarios. In production code, you are usually more interested in the state change that the action caused, rather than the action status.

However, one possible use case in production is taking some action only if the action completed.

As an example, suppose you want to save some info, and you want to leave the current screen if and only if the save process succeeded.

You could have the following save action:

class SaveAction extends AppAction {     
  Future<AppState> reduce() async {
    bool isSaved = await saveMyInfo(); 
    if (!isSaved) throw UserException('Save failed');	 
    return null;
  }
}

Then, in your widget, you can write:

var status = await dispatch(SaveAction(info));
if (status.isCompletedOk) Navigator.pop(context);