Skip to main content

Action status

All actions have a status property that help you do something only if an action finished without errors.

For example, consider this action that saves some information:

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

Then, in your widget, if you want to pop the current screen only if the saving succeeded, use status.isCompletedOk:

var status = await dispatchAndWait(SaveAction());
if (status.isCompletedOk) Navigator.pop(context); // Here!

Testing with action status​

warning

The features below are meant for testing and debugging. You likely will not use them in production. In production code, you are interested in state changes, not action statuses.

The status property is of type ActionStatus.

You can read the action status at any time, while the action is running, and after it finishes. However, since the status object is immutable, it always shows the state of the action at the moment you read it:

var action = MyAction();

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

dispatch(action);

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

Has the action completed?​

  • action.status.isCompleted: Use it to check if a dispatched action has finished. It will be false if the action is still running or has not been dispatched yet.

  • action.status.isCompletedOk: Use it to check if the action finished without errors (that is, both before and reduce ran without throwing errors).

  • action.status.isCompletedFailed: Use it to check if the action finished with errors.

Example:

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

Or you can get the status directly from dispatchAndWait:

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

Getting the action error​

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

var error = action.status.originalError;

It is called the "original error" because it comes from the before or reduce methods. However, it may have been changed by the wrapError() method.

To get the changed version, use:

var error = action.status.wrappedError;

How far did the action run?​

You can check if the action 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);